ပ္တံင်ထင်းသင့်လိက်ပဝ်ႋ:SVG

SVG (scalable vector graphics) is an accepted file format on Wikimedia Commons. It is suited to diagrams, maps, and other non-photographic images. SVG is highly appreciated on Commons because it describes graphical objects with source code and thus currently provides the best way to modify and improve content.

SVG files are used extensively on Wikimedia Commons. Here are a few tips to get started (if you already know what program you will be using to generate such files, consider visiting Help:Illustrator or Help:Inkscape in addition to the following).

Scalable Vector Graphics (SVG) is an XML specification and file format for describing two-dimensional vector graphics (as opposed to a "bitmap" or raster graphic) in both static and animated forms. It is stored in either plain text or compressed (binary) format which is much more size efficient than most other image formats such as JPEGs or GIFs. SVGs also allow embedding of raster graphics and editable text.

librsvg (alternatively "RSVG") is the rendering library used by MediaWiki to rasterize the SVG files into the PNG bitmap format that is served to Wikimedia pages. The displayed image is not SVG and is therefore not animated or interactive. One reason for this choice is that rendering an SVG in real-time slows down older computers or operating systems. A raster version which can be efficiently converted from the SVG source helps overcome this technical problem. Another reason is that some SVG files are large (e.g., 1 MB), but the image when displayed on a monitor might be 160×320 pixels, which would be an uncompressed 51200 pixels (153600 bytes for 24-bit color).

As of May 2023, Commons is running librsvg 2.44.10 (phab:T193352), already four years old by the time of its adoption. This is an early version of the librsvg rewrite in Rust programming language. Although it manages to fix longstanding problems such as the mask bug (phab:T55899) and provides initial support for SVG 2.0, some fixes on the upstream remain unavailable to us due to our old Debian release. See (phab:T265549) for the latest updates.

Several of librsvg's missing features and bugs impact SVG images on Commons. Consequently, SVG files need to avoid or workaround those problems. For example, librsvg does not support the text on a path feature, and librsvg has problems with top-to-bottom text. Even where librsvg works flawlessly, there can be compatibility issues if an SVG file uses a font that Commons does not have, for example.

See § Not displayed text (Flowed Text bug)

For MediaWiki, the Serbian pages have a common source than can be rendered in either Cyrillic or Latin script. Similarly, the Chinese pages have a common source that can be rendered in either Hans or Hant. Ideally, a Chinese reader could select the Hans script, and all the images in the article would also be rendered in Hans. The desired effect would be something like

It is not clear whether or how this can be done in MediaWiki.

The maximum size of an attribute or text node of an SVG in MediaWiki is 10 MB. This means an embedded raster image cannot exceed 6.9 MiB in size. Using embedded raster images is discouraged.

Programs you can use to create SVG images are shown in the § Editors hereafter. Alternatively you can edit the SVG code directly with any text editor or IDE.

The following sections explain specific features of SVG.

Although not a requirement on Commons, it is a good idea to run your file through the World Wide Web Consortium (W3C) XML validator (https://validator.w3.org) before you upload. The validator can find problems with an SVG file that may cause the file to render incorrectly in different platforms. For example, validation will complain about the use of flowText elements, which are nonstandard and poorly supported. However validating a file generally does not justify a reupload,^[3] for exceptions see Optimizing SVGs that have already been uploaded.

If the SVG file has a DOCTYPE declaration, then the validator will use that DTD to check the syntax. If there is no DOCTYPE (which is not required nor is it recommended),^[4][5] then the validator may check that the file is well-formed XML, but it may realize the file is SVG and perform non-DTD validation by passing the file to its nu Validator.

From the W3C validator web page, one can select to validate the file as SVG 1.1. (In the upcoming SVG 2 Draft, references to the SVG DTD will be removed.)^[6]

If additional namespaces are present in the SVG document, the validator will complain about them. Many tools, such as Adobe Illustrator and Inkscape, insert nodes in additional namespaces.

Other namespaces will still cause validation errors. The W3C nu Validator can be told to suppress errors about other namespaces with the nsfilter parameter.^[7]

In addition, non-SVG 1.1 attributes will produce validation errors. The SVG 2.0 draft allows users to include arbitrary data-* attributes just as HTML 5.0 does, but the W3C validator will complain about them.

See § Tagging SVG files for how to tag a file as validated.

Different software programs and different browser platforms may render the exact same SVG file in slightly different ways. The way you see your final image in a vector image editor may not reflect how that image will look once it is uploaded to Commons and is viewed by others. Also, all SVG images are automatically converted to PNG files when used in a Wikipedia article, and this may affect how the final image looks as well. As an example of the former, in an image containing a series of very fine strokes, those strokes will probably look much more bold and thick in the editor than they will once the image has been converted to SVG and viewed in a web browser.

Those who create SVG files should consider saving their work in SVG format and then opening that same image using two or three different browsers to verify that it is rendering as intended. A similar check can be done by opening the file in other image editing programs as well.

To preview how an SVG will be rendered to PNG on Commons, go to Commons SVG Checker.

The reasons why the same file becomes rendered differently depending on context is a result of how these contexts (browsers or programs) interpret the file’s SVG code and use that code to generate the image. Aim to create a "least common denominator" SVG that renders correctly no matter what browser is used to open it, and never assume that your own image editing program is showing you what the image will really look like to other viewers. Previewing SVGs in a Web browser (rather than vector graphics editor) can reveal some problems. It is sometimes helpful in tuning and tweaking the SVG code, especially in conjunction with DOM Inspector tools.

Also, some programs will allow you to insert raster-based components into your file without warning you that if the file is converted into SVG these components will not simultaneously convert to vectors, meaning that you may need to be very careful about the sorts of filters and effects you include in an image and should check for any extraneous embedded "links" within an image before you upload the SVG to Commons. How to do this will vary from program to program.

However, if you are using Adobe Illustrator, here are examples of things which will cause Illustrator to convert a path into a raster component:

These are just a few examples of things which will cause Illustrator to produce a raster when a vector was intended. The simpler these paths can be, the more likely Illustrator will be able to retain them as vectors.

For more information on how to check SVG files for MediaWiki, see § How SVG files work in MediaWiki.

The source code of every SVG file SHOULD begin with the XML processing instruction.^[8] The XML processing instruction specifies the version of XML and the character set.^[9] The W3C insists that character encoding declaration SHOULD be used,^[10] (the W3C's validator warns only for its absence).

The software with which you create or edit the SVG file should provide the option of choosing character encoding. UTF-8 is RECOMMENDED for internationalization as opposed to ANSI or Unicode encodings other than UTF-8. The absence of the XML declaration will lead to a mild confusion when the SVG source file on a Wikimedia server is opened in a browser: the raw XML code will be displayed instead of being rendered into an image. This is not an issue if you download the source SVG file to your device and open it locally.

A DOCTYPE declaration with its DTD is not needed and it is official not recommend to use a DTD,^[5] but neither it is recommended to not use a DTD. SVG 1.0 and SVG 1.1 have DTD specifications, but SVG 2.0 will not have one. The SVG DTD will validate the SVG, but the DTD is not aware of any extensions. Consequently, a DTD validator will list as errors RDF metadata and the additional elements and attributes that Inkscape includes with its SVG output. Wikimedia servers also restrict what can be included in a DTD's internal subset, so it is no longer possible to extend the SVG DTD to include additional elements and attributes.

The svg root element should follow. It MUST specify the XML namespace for SVG, xmlns="http://www.w3.org/2000/svg";^[11] without the SVG namespace, an SVG image will not render. (The default namespace is specified with xmlns.) Other namespaces may be included in the svg element. For example, if the file uses linking,^[12] then the xlink namespace xmlns:xlink="http://www.w3.org/1999/xlink" should be declared.

The SVG version number SHOULD be included (typically 1.1). Software normally supplies these namespace declarations and may include other namespaces.

The defaults for the width and height attributes are "100%", and those defaults will permit automatic scaling. An image that specifies width="400px" is declaring that it wants to be displayed at a size of 400 pixels instead of neatly filling its container. Unfortunately, many software tools specify a fixed size for these attributes. The svg element should specify a viewBox^[13] attribute. The view box specifies the displayed portion of the image; the view box is translated and scaled to fit the width and height of the container.

There are some valuable uses of bitmap images within SVG files, such as annotating a photograph (e.g., labeling the parts in an anatomical photograph; the labels can be easily translated), which takes the best from the two worlds: vectorizing a photograph or ray-traced image would produce large files that scale unnaturally and poorly, while rendering any added fonts and hard edges into a pure bitmap would lead to a loss of detail when scaled, and ringing around the edges. However, most uses of bitmaps in SVG files are not necessary and bitmaps are often better converted or redrawn as vectors. Bitmaps should be included within an SVG file if for some reason this is the best solution, but should be redrawn as vectors if this yields an overall better or more informative image. Further, other editors who come across the image on Commons may decide to apply the tag {{BadSVG}} to an SVG image containing undesirable raster-based elements.

Please think carefully about using bitmaps in SVG files, and consider converting them or redrawing them as vectors when incorporating them into an image rather than including a bitmap directly. See the talk page for further discussion of this issue. If you do decide to use a bitmap image, please be sure to embed and not link to the image; otherwise it won't render.

SVG images can be animated, but because the SVG is converted to raster PNG format for use in Wikimedia projects, the animation only shows when the SVG file is loaded into the browser. From an article page, that involves clicking on the image to reach the File: page, and then clicking on that image to load the SVG.

The original method of animating SVG uses SMIL. More recently, CSS animation is available.

SMIL is seeing diminishing support across browsers. Internet Explorer did not support it; Google deprecated SMIL in 2015 with the possibility that it may completely remove SMIL from Google Chrome in the future.^[14] As of July 2018, SVG SMIL animation is available in most browsers except Internet Explorer, Edge, and Opera.^[15]

See § Tagging SVG files for how to mark an SVG file as animated.

The title element right under the SVG element serves as the title name of the SVG image itself, but it can be also applied further inside of the descendant elements within the SVG image. Most modern desktop browsers render these titles into popup tooltips which help readers to identify the meaning of the object on mouse-hover even if there is text label by the object.

Similarly, title can also be applied on text too for collapsing message but it may be a good idea to give some hint of the existence of the title element by using text decoration like underline. XML comment is more suitable for technical information which should not be displayed to the reader normally but other users who may edit the SVG source code.

Currently most mobile browsers can not display any title content innately except for the one right under the SVG element because there is no equivalent of hovering the pointer on mobile devices.

For security reasons, MediaWiki does not accept SVG files containing the following patterns:

To sanitize problematic svg files, you can use https://svgworkaroundbot.toolforge.org/ (enable sanitize potentially dangerous commands), more details can be found at User:JoKalliauer/IllegalSVGPattern.

Due to limited abilities, the XML-Parser does not recognize and block the following patterns:

Before saving the final version of an SVG image you should remove any references to other files you used to make the SVG (this is what is meant by "linking"); if these references are left in the SVG text, then the renderer will not find the external file(s) and will fail. Wikimedia blocks such uploads, so they can't be uploaded any more.

It’s also a good idea to remove or "vacuum" any unused definitions (defs), as these can needlessly bloat the size of the file (except when you need them for further edits, such as default templates).

There are three common SVG optimizers: scour, svgcleaner and svgo, but be aware that all three optimizers have dozens of open bugs and are not actively developed any more,^[16][17][18] for more optimization options and how to use them see using Optimizers.

But be aware that tidying up is controversial and often undesired, see When is optimizing/validating files undesired? for details and reasons. Tidying up or validating does not justify a reupload^[19]. Invalid elements and attributes are often necessary for correct rendering, and should not be removed^[20].

Inkscape and other programs also allow users to save files in SVGZ (compressed binary SVG) format. This format is not supported on Commons and should not be applied to any images uploaded here. Such images cannot be uploaded.

Be aware in Adobe Illustrator and Inkscape are different options to save, see Help:Inkscape#Inkscape SVG vs. Plain SVG and Help:Illustrator#How to save as an Illustrator SVG.

In Inkscape there are three possible svg-options: "Inkscape SVG", "plain SVG" and "optimized SVG". Inkscape SVGs is the best fileformat to reedit the file in Inkscape, otherwise informations such as layer or grids will be removed, such images should be taged with {{Created with Inkscape|IMPORTANT=yes}} to show they should not be optimized. Plain SVG will be rendered identical as Inkscape SVGs and are a bit smaller. Optimized SVG uses a optimizer called scour, which can reduce the file-size even more and offers some workarounds for librsvg-bugs, such as phab:T217990^[21].

A number of free fonts installed on Wikimedia server can be rendered using the <text> tag. You can find sample renderings on MetaWiki or the raw list. Web fonts are not supported at all. Some fonts are not available in Regular style, only in Bold or in others such as Italic; consider alternatives like Liberation. Please consider using these fonts and not converting text to paths for the following reasons:

In addition, if fonts are converted to paths, there may be copyright issues if the font does not have an acceptable free license. (Such vector images become derivative works of the font.) See also: WP:PD#Fonts and typefaces

SVG files which should not convert text to path shape may be tagged with {{Path text SVG}}. For linking text modifiable (what we have been calling "text" or "font") and text non-modifiable (i.e., path-based) versions of an SVG file use {{Vector text versions|…}}.

If you still insist converting text to path for reasons like the lack of support of textPath function or rare glyph which is not present in most typefaces, you should duplicate the raw text group to overlap the converted text and add the attribute fill-opacity="0" stroke-opacity="0" to this group in order to hide the raw text. This way the text in the original SVG file can still be searched, clicked and highlighted by readers manually. opacity="0" may lead to some misunderstanding because it will make the highlight invisible while still selectable. display="none" prevents readers from searching the text without accessing the source code.

Converting text to outline (path) before exporting SVG is particularly popular among Adobe Illustrator users because the vector graphic software does not convert text-align attribute to text-anchor and the fallback fonts on Wikimedia have different font metrics than the chosen font by the image contributor. This leads to incorrect text positioning and encourages users to ignore the benefits of maintaining raw text in the vector file.

Inkscape supports a feature known as "Flowed Text" which automatically wraps text to fit into the bounds of a given text box. Unfortunately this feature is part of SVG Tiny 1.2, which nobody supports. Its usage will almost certainly result in compatibility problems.^[22] On Wikipedia, a flowed text box does not render at all (phab:T43424 - depending on font size and color).

To avoid this issue in Inkscape:

• The easiest solution is to only use a single click (without dragging) to create text with Inkscape’s text tool. (In contrast when holding the mouse button and dragging the mouse to draw a text box, you're specifically telling Inkscape to use Flowed Text).

However there are some easy ways to fix this issue:

If you accidentally created a Flowed Text box which is empty (i.e. contains no text) it’s not visible or selectable in Inkscape but it still shows up as a black rectangle on Wikipedia. To delete it there are some possibilities:

Font scaling currently does not work as expected if horizontal and vertical scales (according to the effective transform matrix) are not equal (the horizontal stretch will be ignored: only the font height, computed from the matrix is currently honored); this can prevent the correct rendering in narrow/condensed or width-extended styles from another font, with text taking unexpected width and flowing out of the expected box (the alternative is to select an alternate free font family which is already narrowed/condensed).

Text is guaranteed to be misplaced (and in some case, ugly kerning) if the resolution of the PNG render is not the same as the native dimension defined by the SVG file itself regardless of how "regular" the scaling multiplier is (e.g. 0.5, 2 or 4) (phab:T36947).^[31] In any case, do not use extremely small (>10px) or large font-size and then scale the text or the whole image to your desirable size. Always begin with a reasonable font-size (unfortunately a size around 80px is preferable).^[32]

Beware also with font metrics differences: an SVG file may look good when rendered directly in a SVG-capable (all modern) browser under Windows or Mac OS (which can use common, but non free fonts such as Courier or Courier New), but will look other when restricted to the list of free fonts currently supported by the MediaWiki’s SVG-to-PNG renderer (or when viewed under OSes like free distributions of Linux), see also section "Font substitution and fallback fonts".

The attribute textLength isn't fully supported and could not rendered correctly. See phab:T15387.^[33]

RSVG recognizes writing-mode property, but there are problems with some fonts on Commons (especially the default font). That some fonts work suggests that the problem lies with the font rather than RSVG. The problem is the vertical spacing causes the characters to overwrite each other (phab:T65236). For example, the typical way of producing vertical text does not work:

The workaround is to specify a font that works rather than relying on the default Chinese font (which is probably WenQuanYi Zen Hei). Suitable fonts are Noto Sans CJK SC or AR PL UKai TW or monospace.

SVG font specifications may use a specific font family such as Arial or Times New Roman. Such a font specification usually means the user agent must have access to the font file with that name. Unfortunately, many fonts are proprietary and are not available on all operating systems. For example, not all operating systems have the proprietary Arial font. If the specific font family is not available, then some default font will be used; the default font may have a much different appearance. For the user agent librsvg, the default font is Liberation Serif.

Many user agents have a font substitution table that allows the user agent to substitute a font family that is close. To improve the font matching, SVG allows the font-family to be a list of font family names; the user agent will use the first font family that it recognizes. The graphic artist might list similar Microsoft, Apple, and Unix fonts to improve the chance of the user agent having the desired font. Additionally, SVG supports the CSS generic font family specification.^[34][35] That means most SVG user agents should support the generic font families of serif, sans-serif, cursive, fantasy, and monospace. It is good practice to use a generic font family as the last entry in the font family list. For the librsvg on Commons:

• sans-serif maps to DejaVu Sans
• serif maps to DejaVu Serif
• cursive maps to the uninteresting DejaVu Sans
• fantasy maps to the uninteresting DejaVu Sans
• monospace maps to DejaVu Sans Mono

On Commons, librsvg has the fonts listed in m:SVG fonts#Latin (basic) fonts comparison. Using just those fonts will get good results in Wikipedia articles that display their images using librsvg, but graphic artists should also be aware that SVG files may be displayed by other user agents. Consequently, it is best to use common font families (such as Arial) or a list of font families that ends with a generic font family (such as Trebuchet, sans-serif).

The font metrics for generic font families such as sans-serif will likely vary widely on different user agents. In graphic illustrations metric exact text elements are often important and Arial can be seen as de-facto standard for such a feature. Adding both Arial and sans-serif as fallback fonts will help the SVG to be displayed with best effort on machines that do not have or substitute Arial. To make the SVG file independent of Arial, change all occurrences of font-family: Arial to font-family: 'Liberation Sans', Arial, sans-serif.

If you are using non-Western characters, you should define those typefaces preceding Liberation Sans. For example, if your text contains Chinese characters, font-family definition should be: ‘ Liberation Sans, Arial, WenQuanYi Zen Hei, SimHei, sans-serif’. In this case, western fonts are put in the front because the quality of Western characters in Chinese fonts is often low, and we want to use the higher-quality ones first.

• Inkscape begins supporting fallback fonts from version 0.91.
• Adobe Illustrator version 18.1.1 or earlier (probably in later versions as well) does not support fallback fonts, so the SVG file has to be manually updated in a text editor after it is saved.

Although you can use only the text element to render simple text in the image, the tspan element can be useful to handle text which the position of the word is dependent to the other.^[37] A tspan element must be nested within the text element, and then more tspan can be nested within this tspan, all styling defined in the parent text element will be inherited by its child tspan elements. For example:

The primarily difference with the "g nesting text" structure is that few important text layout behaviors are exclusive to tspan: When multiple text elements are lined up consecutively, they still position themselves independently; if multiple tspan elements are lined up consecutively but the second and subsequent tspan elements are not given absolute x coordinate, text of these tspan elements will line up horizontally right next to the end of the character of prior tspan in the same text element.

However, tspan should be used sparingly even if you define the absolute x coordinate for every single tspan element in the text element. This is because under the default xml:space definition, any line break (within text or tspan) with an extra trailing white-space is converted to a blank space character automatically.^[38] If there happens to be multiple consecutive line breaks, they are treated as one space still. This would not be a problem if the line break is followed by a tspan element with absolute x coordinate and is align to left (text-anchor=start, the default value). If xml:space is given the 'preserve' value, librsvg will translate the indent to a long white tab character equal to 8 space characters. Because the auto-formatting or re-indentation (indent style) of most XML editors creates indent for every new descendant XML tag automatically, use re-indentation carefully if your SVG file contains such usage of tspan.

The behaviors in different SVG renderers to this issue varies much and is usually inconsistent to the W3C specification (also the 'preserve' value of xml:space will be deprecated in SVG 2.^[39]). The only problem with librsvg is that it never converts the line break alone into space no matter which value of xml:space is given if there is no trailing space or indent before the tspan tag. Except for librsvg, nearly all modern browsers always add the converted space character right after the preceding text, this is the reason why the end or middle values of text-anchor property always align the text 1 space leftward because the new line and/or the trailing tab or space after the closing tspan tag is converted to an unexpected space character.^[40]

Inkscape is buggy to render tspan, for example, inheriting text-anchor property from the first tspan element incorrectly for the subsequent tspan elements even if the property is specifically given a value in all tspan elements.^[41] In such case, simply revert the "text nestling tspan" structure to just "g nestling text". Inkscape also defaults to xml:space="preserve" to deal with space between tspan. If you are completely concern with how your SVG appears in Inkscape but prefer the default xml:space handling, use   to replace each general space so it will not be hidden in Inkscape.

If you are generating an SVG using Adobe Illustrator, you will be given options to "Output fewer <tspan> elements" and "Use <textPath> element for Text on Path" during the save dialog. To maximize the consistency of the appearance of your font across browser platforms, you should place a check mark next to the former and make sure there is no check mark next to the latter. If you do not do this, the kerning of some of your letters may cause them to overlap (depending on your browser).

SVG 1.1 does not provide any form of line wrap (either hard or soft). Any line wrap should be done manually by repositioning new text or tspan elements with the same absolute x coordinate and a new y coordinate. For tspan elements, the next line's y coordinate can be set with the dy attribute. Although textPath can handle a similar situation,^[42] this element is not supported by librsvg/Wikimedia (phab:T11420).

A draft of SVG 1.2 did address line wrapping, but there is little support.

The draft of SVG 2.0 also addresses line wrapping, but Chrome, Firefox, Edge, and librsvg do not support it as of May 2018.

Usually it is simply gratuitous use of the ‘style attribute’. To ease the process of updating font-family for every text or tspan elements, you can define the font CSS class(es) within ‘style element’ and apply the class property in elements like this:

CSS class defined in ‘style element’ can also be used for other SVG elements (e.g. g and path) despite the misleading type="text/css" attribute. Even if one particular style is defined once in the SVG, it is still advised to replace the style with class for a tidier layout of XML codes.

Contrary to popular belief the style attribute does not separate content from presentation, and unless you need to override properties set by a CSS selector, it is best to use the SVG formatting attributes instead (e.g. <path fill="#fff" stroke="none"/> instead of <path style="fill:#fff;stroke:none"/>).^[43] However, if you need to override the element style defined in style element, you do need to employ style attribute. If you need to override the style for text element without style attribute, you can use a tspan element container to nest the text you need to override the style, presuming there is nothing predefined in style element for tspan element.

Note

• phab:T68672 – CSS style element get ignored if the default value type="text/css" is omitted.
• phab:T43423 – CSS child selectors are not supported by librsvg.
• phab:T68551 – CSS classes on text elements get not inherited on child tspan elements. If you want this, you need to add a separate class for tspan as well, or use simply groups (but not in the text element as it Scour unfortunately does).

Sometimes the text might be unreadable because the background color has low contrast with the font color or the pattern is too complicated that confuses the reader. This can be solved by duplicating the text in exactly the same position, but the back text rendered with stroke and the fore text without it like this:

• "stroke-linejoin:round" is defined to avoid sharp corner of the text stroke.

The problem with applying stroke and fill to the same text element is that the stroke will be rendered over the main body of text, making it otherwise unreadable if the font is too small but requires a larger stroke to be distinguishable from the background.

SVG filters can be used to draw the text over a dilated version of the text. The filter first expands the text, sets the color of the expanded text, and then draws the original text over the dilated version. One filter can be defined, and that filter can be used by several text blocks:

SVG filters can also be used to size an opaque rectangular background that surrounds the text. Using a filter is more robust than painting a rectangle and then painting the text on top of that rectangle. A fixed-size rectangle may not fit the font used for the text; the size of the rectangle would also need adjustment if the text changes. If the text is translated, for example, the rectangle may need to be changed. Using a filter automatically adjusts the size.

Outlining text can be done without filters by explicitly rendering the text twice. The first time, the text is rendered with a white stroke to set the outline. The white outline erodes the text. The text is rendered a second time, but this time the text is not stroked. Consequently, the characters are rendered full size (without erosion).

If you have lot of text that needs to be rendered with a stroke background, you can manually include the text within <g>, <text> and <tspan> elements. The <g> element which will be rendered underneath, apply the stroke, then <use> the text group of <text> element without a stroke and fill the font with contrasting color:

W3C includes paint-order property in SVG 2.0 which allows the order to render the attributes of "fill", "stroke" and "markers" within one element arranged by the user manually, instead of following the default mandatory order.^[44]

Mozilla Firefox also includes this attribute experimentally but it defaults to disable in the stable release until SVG 2.0 matures. This feature can be enabled in the about:config entries of Firefox.^[45]

Users of Inkscape version 0.46 may notice that images with "Fill gradients" display perfectly on Inkscape, but display "messed up" in Opera or Firefox browsers. One possible cause is that the last "stop" on a gradient has opacity set to 0. Inkscape appears to ignore this last stop, but both Firefox 3.0.6 and Opera 9.36 will render it as a white border in the filled object. Solutions are either remove the last stop (because it was probably created in error) or change the opacity (and colour) so that the image renders correctly in browsers.

Note that Inkscape adds a JavaScript polyfill to SVG images containing mesh gradients. Scripted SVG images cannot be uploaded to Wikimedia Commons, but removing the JavaScript code will break the gradients.

Users of Adobe Illustrator CS5, CS6, or CC and who also use Firefox may notice that an Illustrator "symbol" containing a gradient will render normally as a Commons PNG file but if the SVG file itself is opened in Firefox these symbols will appear vacant. Other browsers will have no difficulty— Google Chrome, even Internet Explorer will render Illustrator’s SVG symbol gradients correctly, but because of a known bug that the designers of Firefox have been aware of since 2005 (Mozilla’s Bugzilla bug 376027 and other reports that lead to it such as bug 353575) but have so far failed to adequately fix, Firefox will display such symbols as empty shapes (symbol strokes and symbol paths without gradients are unaffected).

Adobe Illustrator users should also note that any Illustrator "symbols" containing paths with both a gradient and a filter will be rendered as a PNG in Commons only within the first instance of the use of that symbol. Subsequent use of a symbol containing these paths will render the paths (though not the entire symbol) as blank (neither gradient nor filter nor fill nor stroke will be applied).

Wikimedia’s SVG renderer currently supports various filter effects, but some effects such as gaussian blur (feGaussianBlur) behave differently when the blurred object exceeds the edge of the actual image. The current version of RSVG will treat the cropped edge as the actual edge of the object to apply the effect (as if the object has applied clipPath before applying filter effect), creating an undesirable filter effect against the image edge.

• The maximum file size on Commons is 4 GiB (4,294,967,296 bytes) for users of UploadWizard and other tools that support chunked uploads. Although big files can be uploaded, they cause problems when user opens the file.
• The maximum size for thumbnails for SVG files is 10 MB.
• the recommended image height is around 400–600 pixels

If the file is too big, reduce/optimize it by:

SVG files can be translated and can be multilingual (have embedded translations). For more information, see Commons:Translation possible/Learn more.

Given an image file that is in a format other than SVG, there are various ways to convert it to SVG; see § Converters for programs.

Note: For vector images where the vectorization was done by a third party, there is the issue where the vectorization code may have its own copyright even if the depicted image itself is out of copyright or below the threshold of originality. See § Copyright for more info.

Generally, there are 3 ways to produce an SVG file, given an existing image:

1. Regenerate it
2. Convert it
3. Create a new one

If you are unable to convert an image yourself, please add the tag {{Convert to SVG}} to flag that the image should be converted. Some images are not well-suited to SVG, notably continuous-tone images such as photographs. These generally should instead be stored as JPG.

If the image was generated by a program (rather than drawn by hand) — for example, a chart from a spreadsheet — it may be possible to set the output format to SVG, rather than PNG or other format, and thus produce an SVG image from the same source. If possible, this is generally easiest.

Many vector file formats can be easily converted to SVG simply by changing the format (repackaging the existing data), by using a converter program. This may be as simple as opening the file in a vector image editor and then saving it in SVG.

For raster (bitmap) graphics, this cannot be done because the image is a set of individual pixel values, not a set of strokes (vectors). For these images (notably PNG images), one can convert to SVG via "vectorization" or "tracing" — automatically generating a vector graphic from a raster image.

Many SVG editors have tracing functions, and dedicated converters exist. In Inkscape, this is done by the potrace program.^[49][50] Concretely: open the bitmap (File → Open… (Ctrl-O)), then select Path → Trace Bitmap… (Shift-Alt-B). There are various options; after using, please delete the underlying bitmap, and consider simplifying the path to reduce the number of nodes (Ctrl-L).

Adobe Illustrator also allows for the conversion of bitmap images into vectors via its Image Trace function. Care must be taken when doing so that the resulting vector image is neither ponderously large (often the result of too much conversion fidelity with regard to color and shape) nor so simple that it loses faithfulness to the original image. Converted images almost always require some manual correction after conversion. As in Inkscape, the underlying bitmap should be removed after conversion is complete.

It should also be noted that when Illustrator converts one of its files into an SVG file, it tends to convert a number of shading effects such as "inner glow", "outer glow", and gradients applied along or across a path into undesirable raster images which it then embeds in the SVG image using links. Such embedded images can often be immediately detected by viewing the image in a web browser under high zoom where they will appear cloudy or have visibly jagged edges (neither of which is ever true of a correctly rendered vector image). As these effects were originally created without regard to the W3C consortium, Adobe does not offer and is never likely to have a solution to the problem.

In order to remove raster components from an Adobe Illustrator-generated SVG prior to uploading the image to Commons, the artist must first be able to identify where Illustrator has put them. This can be done in the following way:

First finish editing an image file and save in Illustrator’s AI format (*.AI), then save it again in SVG format. During the second Save dialogue, choose to "embed" the links (for now). Then close out the image (File=>Close or Ctrl+w). Next, open the SVG version back up again, click on "Window" from the right side of the top menu bar, and scroll down to "Links". This will open up a small window containing information about each of the links (if any) which currently exist in the SVG image (whether or not Illustrator produced them). You can click any of the entries in the top half of the window and then select the "Go to link" button located in about the middle of it-- this will take you to that particular raster so that you can identify it and either remove it or replace it with a non-raster based alternative.

Note that this SVG version of your image, when viewed in Illustrator, may look very different from the same SVG file you thought you had saved just a few minutes prior: this is because Illustrator has made a set of codes during the creation of that file which it then has difficulty reading (SVG is not an Illustrator-proprietary format, AI is, and so while Illustrator will never have difficulty correctly viewing an AI (Adobe Illustrator) file, it will sometimes struggle to correctly render an SVG, even one that it itself produced). Fortunately, even an SVG that looks confusing in Illustrator will usually at least appear to render correctly in most browsers (with the occasional and already noted exception of Firefox) and in Inkscape.

If an image cannot be regenerated or converted, the remaining option is to recreate it — draw a new SVG image, using the existing image as a model. This is manual and the most time-consuming option, but may ultimately yield the highest quality.

In all cases, it may prove useful to touch up the resulting image in an SVG editor — perhaps adding details which are hard or impossible to produce in the originating program, or simplifying or refining a complex conversion (such as simplifying a path described by 100 points to one described by 5 points, if extra points add unnecessary detail).

Once you have created an SVG image, upload it (under a new name), and tag the original raster image with {{Vector version available}}, but please do not delete the raster image or list it for deletion, as it still serves some purposes — see Commons:Superseded images policy for details.

Every SVG file uploaded to Wikimedia Commons should show how it was made: use template {{Inkscape}}, {{Adobe}}, {{HandSVG}}, etc.

You should check the appearance and the validity before you upload the file; use the tool Commons SVG Checker

If you are not sure or want to see first how librsvg will render your file, upload it to Test.svg

Uploading is described at Commons:First steps/Uploading files.

Make sure to fill out the {{Information}} box as fully as you can. Often, it’s a help when an image has a complete information box as this makes categorization by others easier and allows others to make translations.

See the § SVG software tags section for detailed information on a SVG media.

All SVG graphics should be sorted into the appropriate subcategory or subcategories of Category:SVG files. Please do not place images directly in the parent category as it will become overcrowded and useless (we have thousands and thousands of more than 100,000 SVG files).

Sort subcategories which rely not on subject but on technical aspects ("created with…", "animated", "valid", and so on) by '*' to keep them outside the alphabet listing.

The main tree is Category:SVG, as a part of Category:Images → Category:Media types.

Concerning the creation of topical subcategories, it is unnecessary to rebuild the complete hierarchy tree of Category:Topics. Normally, it is enough to gather some topics into one. For instance, Category:SVG colors could contain all color-related SVG files of Category:Colors, so it’s pointless to create Category:SVG red, Category:SVG blue and so on. Maybe some subcategories will become useful later, but stay close to the existing topics tree, and do not put any SVG files only into a SVG category: Categories are primarily for finding media, not for hiding them. Do not over-categorize.

See Commons:Categories for general information.

Category names start with "SVG" followed by the topic in lowercase (unless it’s a proper noun). For example, a category containing SVG files related to chemistry would be called Category:SVG chemistry. There was no naming convention for a long time, thus you may see titles that do not match this format. These will be converted over time.

See Category:SVG marker templates for all SVG markers available.

When you upload your SVG to Commons (or any other MediaWiki wiki), the software automatically produces PNG thumbnails, embedded in the articles and the description page. If you download the image (usually by right mouse clicking on the image), you will get the PNG image. If you want the SVG file you must save the link to the image instead of the image itself. This works (by right mouse clicking on the link under the image) only on the description page of the image, not on the thumbnail in the category page.

MediaWiki uses librsvg to convert SVG files to PNG files for display (SVG rendering), it has some long and well-known bugs that should be fixed, so you might want to check your file with that program before uploading. You can test the SVG with SVG Check for accurate PNG render preview and W3 XML validator for possible code errors or incompatibility of SVG elements or attributes.

Further information: MediaWiki SVG limitations.

What this means: Say you want to produce a large version of your SVG for detailed maps, or using in-bitmap software like gimp, or calligraphy printed out one character per page, or something like that. You need to force MediaWiki to produce a huge PNG thumbnail, by using https://commons.wikimedia.org/w/thumb.php?f=Foo.svg&w=1000 or by doing something like [[File:Foo.svg|1000px]] in the sandbox or your talk page or somewhere else unimportant. Printing this giant PNG will look much better than if you try to scale up one of the default thumbnails! Of course, you can also use for-printing SVG software like Inkscape but sometimes that shows something other than what’s shown on-screen (black background, other fonts, etc.).

Many programs can handle SVG files. You may like to try one given below, though these are not the only programs around. Some are available for free download, while others are commercial software.

As SVG is just an XML specification, it is possible to write SVG files manually in a text editor, or with your own programs/scripts.^[52] In fact, many SVG images are written in text editors. An editor which can highlight the syntax is helpful. Check your work with the W3C SVG validator.

All modern web browsers render SVG natively.

Most SVG editors include a raster-to-vector-converter (image tracing)

There is some concern that the SVG source code of images might be copyrightable as a "computer program" even if the output is an image in the public domain due to being below the threshold of originality or otherwise indistinguishable from a work that is public domain due to copyright expiration. This could mean that even though the output of an SVG, the image, is in public domain, the code could be restrictively copyrighted, and therefore inappropriate for including in Wikimedia Commons.

Elements that weigh in favor of SVG source code containing sufficient creative expression to be copyrightable might include hand-written code, complex embedded CSS, embedded comments longer than short phrases, or a large carefully selected set of control points. Elements that weigh in favor of SVG source code lacking creativity include programmatically generated code or slavish copying of a public domain source. See the following for additional context:

• Example DRs at Commons:Deletion requests/File:Bethlehem Steel logo.svg and Commons:Deletion requests/File:W3C Semantic Web Logo.svg.
• Discussion at Commons:Village pump/Copyright/Archive/2014/03#SVG's are computer software?
• Cases: Adobe Systems, Inc. v. Southern Software, Inc., Alfred Bell & Co. v. Catalda Fine Arts, Inc.. (judgment, commentary), and Meshworks v. Toyota (judgment, commentary)

Maintenance:

• Category:SVG
• Category:SVG maps — The SVG branch of the map project.
• Category:Images that should use vector graphics
• Category:Pictures showing a librsvg bug
• Commons:Transition to SVG