CODEWITHSUNDEEP
svggithubmarkdown
chris Frisina
chris Frisina

Reputation: 19688

Include an SVG (hosted on GitHub) in MarkDown

I know that an image can be placed in an MD with the MD syntax of either ![Alt text](/path/to/img.jpg) or ![Alt text](/path/to/img.jpg "Optional title"), but I am having difficulty placing an SVG in MD where the code is hosted on GitHub.

Ultimately using rails3, and changing the model frequently right now, so I am using RailRoady to generate an SVG of the schema diagram of the models. I would like for that SVG to then be placed in the ReadMe.md, and be displayed. When I open the SVG file locally, it does work, so how do I get the browser to render the SVG in the MD file? Given that the code will be dynamic until it is finalized (seemingly never), hosting the SVG in a separate place seems overkill and that I am missing an approach to accomplish this.

The SVG I am trying to include is here on GitHub: https://github.com/specialorange/FDXCM/blob/master/Rails/fdxcm/doc/models_brief.svg

I have tried the following, with an actual image as well to verify the syntax is working, just that the SVG code isn't being rendered:

![Overview][1]
[1]: https://github.com/specialorange/FDXCM/blob/master/doc/controllers_brief.svg  "Overview"

<img src="https://raw.github.com/specialorange/FDXCM/master/doc/controllers_brief.svg">

![Alt text](https://raw.github.com/specialorange/FDXCM/master/doc/controllers_brief.svg)

[Google Doc](https://docs.google.com/drawings/d/1B95ajItJTAImL2WXISX0fkBLYk3nldea4Vm9eo-VyE4/edit) :

<img src="https://docs.google.com/drawings/pub?id=117XsJ1kDyaY-n8AdPS3_8jTgMyITqaoT3-ah_BSc9YQ&w=960&h=720">

<img src="https://raw.github.com/specialorange/FDXCM/master/doc/controllers_brief.svg">

<img src="https://docs.google.com/drawings/d/1B95ajItJTAImL2WXISX0fkBLYk3nldea4Vm9eo-VyE4/edit">

to get the results of:

Overview 1: https://github.com/specialorange/FDXCM/blob/master/Rails/fdxcm/doc/controllers_brief.svg "Overview"

Alt text

Google Doc :

Upvotes: 266

Views: 249605

Answers (11)

Nadav Aharoni
Nadav Aharoni

Reputation: 311

The following worked for me (December 2024):

![SVG Image](file.svg)

In this case, file.svg is in the same directory as the containing .md file.

An example: https://github.com/NadavAharoni/Oop_5785/blob/main/Module_004/csharp-boxing-unboxing.md

Upvotes: 1

Potherca
Potherca

Reputation: 14640

The purpose of raw.github.com is to allow users to view the contents of a file, so for text based files this means (for certain content types) you can get the wrong headers and things break in the browser.

When this question was asked (in 2012) SVGs didn't work. Since then Github has implemented various improvements. Now (at least for SVG), the correct Content-Type headers are sent.

The easiest way to add SVG is to use the upload assets feature. To quote the manual:

You can upload assets like images by dragging and dropping, selecting from a file browser, or pasting. You can upload assets to issues, pull requests, comments, and .md files in your repository.

Since 2022, "images" also includes SVG:

screenshot animation of SVG file upload

Some comments regarding changes that happened along the way:

  • Github has implemented a feature which makes it possible for SVG's to be used with the Markdown image syntax. The SVG image will be sanitized and displayed with the correct HTTP header. Certain tags (like <script>) are removed.

    To view the sanitized SVG or to achieve this effect from other places (i.e. from markdown files not hosted in repos on http://github.com/) simply append ?sanitize=true to the SVG's raw URL.

  • As stated by AdamKatz in the comments, using a source other than github.io can introduce potentially privacy and security risks. See the answer by CiroSantilli and the answer by DavidChambers for more details.

  • The issue to resolve this was opened on Github on October 13th 2015 and was resolved on August 31th 2017

  • Support for SVG drag-and-drop file upload was announced January 21 2022

Examples

All of the ways stated below will work.

I copied the SVG image from the question to a repo on github in order to create the examples below

Linking to files using relative paths (Works, but obviously only on github.com / github.io)

Code

![Alt text](./controllers_brief.svg)
<img src="./controllers_brief.svg">

Result

See the working example on github.com.

Linking to RAW files

Code

![Alt text](https://raw.github.com/potherca-blog/StackOverflow/master/question.13808020.include-an-svg-hosted-on-github-in-markdown/controllers_brief.svg)
<img src="https://raw.github.com/potherca-blog/StackOverflow/master/question.13808020.include-an-svg-hosted-on-github-in-markdown/controllers_brief.svg">

Result

Alt text

Linking to RAW files using ?sanitize=true

Code

![Alt text](https://raw.github.com/potherca-blog/StackOverflow/master/question.13808020.include-an-svg-hosted-on-github-in-markdown/controllers_brief.svg?sanitize=true)
<img src="https://raw.github.com/potherca-blog/StackOverflow/master/question.13808020.include-an-svg-hosted-on-github-in-markdown/controllers_brief.svg?sanitize=true">

Result

Alt text

Linking to files hosted on github.io

Code

![Alt text](https://potherca-blog.github.io/StackOverflow/question.13808020.include-an-svg-hosted-on-github-in-markdown/controllers_brief.svg)
<img src="https://potherca-blog.github.io/StackOverflow/question.13808020.include-an-svg-hosted-on-github-in-markdown/controllers_brief.svg">

Result

Alt text

Upvotes: 284

Mahozad
Mahozad

Reputation: 24792

You can also insert animated SVG images like any other format.
It can be a good alternative to GIF images.

![image description](relative/path/in/repository/to/image.svg)
OR
<img src="relative/path/in/repository/to/image.svg" width="128"/>

Example (assuming the image is in assets directory in the repository):

![My animated logo](assets/my-logo.svg)

Result:

Upvotes: 9

Mohammad Heydari
Mohammad Heydari

Reputation: 4310

Just like this worked for me on Github.

![Image Caption](ImageAddressOnGitHub.svg)

or

<img src="ImageAddressOnGitHub.svg">

Upvotes: 6

VonC
VonC

Reputation: 1329662

Since Jan. 2022, that seems possible (and easy):

Allow to upload .svg files to Markdown

It is now possible to upload .svg files to comments in issues, PRs, discussions, and Markdown files, like READMEs.

You just have to drag and drop the file in the text area.

An animation showing how to upload a SVG image to an issue comment.

Upvotes: 15

Ciro Santilli OurBigBook.com
Ciro Santilli OurBigBook.com

Reputation: 384404

Update 2020: how they made it work while avoiding XSS attacks

GitHub appears to use two security approaches, this is a good article: https://digi.ninja/blog/svg_xss.php see also: https://security.stackexchange.com/questions/148507/how-to-prevent-xss-in-svg-file-upload

Update 2017

A GitHub dev is currently looking into this: https://github.com/github/markup/issues/556#issuecomment-306103203

Update 2014-12: GitHub now renders SVG on blob show, so I don't see any reason why not to render on README renderings:

Also note that that SVG does have an XSS attempt but it does not run: https://raw.githubusercontent.com/cirosantilli/test/2144a93333be144152e8b0d4144b77b211afce63/svg.svg

The billion laugh SVG does make Firefox 44 Freeze, but Chromium 48 is OK: https://github.com/cirosantilli/web-cheat/blob/master/svg-billion-laughs.svg

Petah mentioned that blobs are fine because the SVG is inside an iframe.

Possible rationale for GitHub not serving SVG images

The following questions asks about the risks of SVG in general: https://security.stackexchange.com/questions/11384/exploits-or-other-security-risks-with-svg-upload

Upvotes: 26

sel-fish
sel-fish

Reputation: 4496

Use this site: https://rawgit.com , it works for me as I don't have permission issue with the svg file.
Please pay attention that RawGit is not a service of github, as mentioned in Rawgit FAQ :

RawGit is not associated with GitHub in any way. Please don't contact GitHub asking for help with RawGit

Enter the url of svg you need, such as :

https://github.com/sel-fish/redis-experiments/blob/master/dat/memDistrib-jemalloc-4.0.3.svg

Then, you can get the url bellow which can be used to display:

https://cdn.rawgit.com/sel-fish/redis-experiments/master/dat/memDistrib-jemalloc-4.0.3.svg

Upvotes: 1

Tanner Perrien
Tanner Perrien

Reputation: 3133

This will work. Link to your SVG using the following pattern:

https://cdn.rawgit.com/<repo-owner>/<repo>/<branch>/path/to.svg

The downside is hardcoding the owner and repo in the path, meaning the svg will break if either of those are renamed.

Upvotes: 9

davidchambers
davidchambers

Reputation: 24866

rawgit.com solves this problem nicely. For each request, it retrieves the appropriate document from GitHub and, crucially, serves it with the correct Content-Type header.

Upvotes: 16

davidchambers
davidchambers

Reputation: 24866

I contacted GitHub to say that github.io-hosted SVGs are no longer displayed in GitHub READMEs. I received this reply:

We have had to disable svg image rendering on GitHub.com due to potential cross site scripting vulnerabilities.

Upvotes: 52

Karsten S.
Karsten S.

Reputation: 2391

I have a working example with an img-tag, but your images won't display. The difference I see is the content-type.

I checked the github image from your post (the google doc images don't load at all because of connection failures). The image from github is delivered as content-type: text/plain, which won't get rendered as an image by your browser.

The correct content-type value for svg is image/svg+xml. So you have to make sure that svg files set the correct mime type, but that's a server issue.

Try it with http://svg.tutorial.aptico.de/grafik_svg/dummy3.svg and don't forget to specify width and height in the tag.

Upvotes: 4

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