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GitLab Markdown
This markdown guide is valid for GitLab's system markdown entries and files. It is not valid for the GitLab documentation website nor GitLab's main website, as they both use Kramdown as their markdown engine. The documentation website uses an extended Kramdown gem, GitLab Kramdown. Consult the GitLab Kramdown Guide for a complete Kramdown reference._
GitLab Flavored Markdown (GFM)
GitLab uses "GitLab Flavored Markdown" (GFM). It extends the CommonMark specification (which is based on standard Markdown) in a few significant ways to add some useful functionality. It was inspired by GitHub Flavored Markdown.
You can use GFM in the following areas:
- Comments
- Issues
- Merge requests
- Milestones
- Snippets (the snippet must be named with a
.md
extension) - Wiki pages
- Markdown documents inside repositories
You can also use other rich text files in GitLab. You might have to install a
dependency to do so. Please see the github-markup
gem readme for more information.
Notes:
For the best result, we encourage you to check this document out as rendered by GitLab itself.
As of 11.1, GitLab uses the CommonMark Ruby Library for Markdown processing of all new issues, merge requests, comments, and other Markdown content in the GitLab system. As of 11.3, wiki pages and Markdown files (
.md
) in the repositories are also processed with CommonMark. Older content in issues/comments are still processed using the Redcarpet Ruby library.The documentation website had its markdown engine migrated from Redcarpet to Kramdown in October 2018.
Where there are significant differences, we will try to call them out in this document.
Transitioning to CommonMark
You may have Markdown documents in your repository that were written using some of the nuances of RedCarpet's version of Markdown. Since CommonMark uses a slightly stricter syntax, these documents may now display a little strangely since we've transitioned to CommonMark. Numbered lists with nested lists in particular can be displayed incorrectly.
It is usually quite easy to fix. In the case of a nested list such as this:
1. Chocolate
- dark
- milk
simply add a space to each nested item:
1. Chocolate
- dark
- milk
In the documentation below, we try to highlight some of the differences.
If you have a need to view a document using RedCarpet, you can add the token
legacy_render=1
to the end of the url, like this:
https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md?legacy_render=1
If you have a large volume of Markdown files, it can be tedious to determine if they will be displayed correctly or not. You can use the diff_redcarpet_cmark tool (not an officially supported product) to generate a list of files and differences between how RedCarpet and CommonMark render the files. It can give you a great idea if anything needs to be changed - many times nothing will need to changed.
Newlines
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#newlines
GFM honors the markdown specification in how paragraphs and line breaks are handled.
A paragraph is simply one or more consecutive lines of text, separated by one or more blank lines. Line-breaks, or soft returns, are rendered if you end a line with two or more spaces:
Roses are red [followed by two or more spaces]
Violets are blue
Sugar is sweet
Roses are red
Violets are blue
Sugar is sweet
Multiple underscores in words
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#multiple-underscores-in-words
It is not reasonable to italicize just part of a word, especially when you're dealing with code and names that often appear with multiple underscores. Therefore, GFM ignores multiple underscores in words:
perform_complicated_task
do_this_and_do_that_and_another_thing
perform_complicated_task
do_this_and_do_that_and_another_thing
URL auto-linking
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#url-auto-linking
GFM will autolink almost any URL you copy and paste into your text:
* https://www.google.com
* https://google.com/
* ftp://ftp.us.debian.org/debian/
* smb://foo/bar/baz
* irc://irc.freenode.net/gitlab
* http://localhost:3000
- https://www.google.com
- https://google.com/
- ftp://ftp.us.debian.org/debian/
- smb://foo/bar/baz
- irc://irc.freenode.net/gitlab
- http://localhost:3000
Multiline Blockquote
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#multiline-blockquote
On top of standard Markdown blockquotes, which require prepending >
to quoted lines,
GFM supports multiline blockquotes fenced by >>>
:
>>>
If you paste a message from somewhere else
that
spans
multiple lines,
you can quote that without having to manually prepend `>` to every line!
>>>
If you paste a message from somewhere else
that
spans
multiple lines,
you can quote that without having to manually prepend
>
to every line!
Code and Syntax Highlighting
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#code-and-syntax-highlighting
GitLab uses the Rouge Ruby library for syntax highlighting. For a list of supported languages visit the Rouge website.
Blocks of code are either fenced by lines with three back-ticks ```
,
or are indented with four spaces. Only the fenced code blocks support syntax
highlighting:
Inline `code` has `back-ticks around` it.
Inline code
has back-ticks around
it.
Example:
```javascript
var s = "JavaScript syntax highlighting";
alert(s);
```
```python
def function():
#indenting works just fine in the fenced code block
s = "Python syntax highlighting"
print s
```
```ruby
require 'redcarpet'
markdown = Redcarpet.new("Hello World!")
puts markdown.to_html
```
```
No language indicated, so no syntax highlighting.
s = "There is no highlighting for this."
But let's throw in a <b>tag</b>.
```
becomes:
var s = "JavaScript syntax highlighting";
alert(s);
def function():
#indenting works just fine in the fenced code block
s = "Python syntax highlighting"
print s
require 'redcarpet'
markdown = Redcarpet.new("Hello World!")
puts markdown.to_html
No language indicated, so no syntax highlighting.
s = "There is no highlighting for this."
But let's throw in a <b>tag</b>.
Inline Diff
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#inline-diff
With inline diffs tags you can display {+ additions +} or [- deletions -].
The wrapping tags can be either curly braces or square brackets: [+ additions +] or {- deletions -}.
Examples:
- {+ additions +}
- [+ additions +]
- {- deletions -}
- [- deletions -]
However the wrapping tags cannot be mixed as such:
- {+ additions +]
- [+ additions +}
- {- deletions -]
- [- deletions -}
Emoji
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#emoji
Sometimes you want to :monkey: around a bit and add some :star2: to your :speech_balloon:. Well we have a gift for you:
:zap: You can use emoji anywhere GFM is supported. :v:
You can use it to point out a :bug: or warn about :speak_no_evil: patches. And if someone improves your really :snail: code, send them some :birthday:. People will :heart: you for that.
If you are new to this, don't be :fearful:. You can easily join the emoji :family:. All you need to do is to look up one of the supported codes.
Consult the [Emoji Cheat Sheet](https://www.emojicopy.com) for a list of all supported emoji codes. :thumbsup:
Most emoji are natively supported on macOS, Windows, iOS, Android and will fallback to image-based emoji where there is lack of support.
On Linux, you can download [Noto Color Emoji](https://www.google.com/get/noto/help/emoji/) to get full native emoji support.
Ubuntu 18.04 (like many modern Linux distros) has this font installed by default.
Sometimes you want to around a bit and add some
to your
. Well we have a gift for you:
You can use emoji anywhere GFM is supported.
You can use it to point out a or warn about
patches. And if someone improves your really
code, send them some
. People will
you for that.
If you are new to this, don't be . You can easily join the emoji
. All you need to do is to look up one of the supported codes.
Consult the Emoji Cheat Sheet for a list of all supported emoji codes.
Most emoji are natively supported on macOS, Windows, iOS, Android and will fallback to image-based emoji where there is lack of support.
On Linux, you can download Noto Color Emoji to get full native emoji support.
Ubuntu 18.04 (like many modern Linux distros) has this font installed by default.
Special GitLab References
GFM recognizes special references.
You can easily reference e.g. an issue, a commit, a team member or even the whole team within a project.
GFM will turn that reference into a link so you can navigate between them easily.
GFM will recognize the following:
input | references |
---|---|
@user_name |
specific user |
@group_name |
specific group |
@all |
entire team |
namespace/project> |
project |
#12345 |
issue |
!123 |
merge request |
$123 |
snippet |
~123 |
label by ID |
~bug |
one-word label by name |
~"feature request" |
multi-word label by name |
%123 |
project milestone by ID |
%v1.23 |
one-word milestone by name |
%"release candidate" |
multi-word milestone by name |
9ba12248 |
specific commit |
9ba12248...b19a04f5 |
commit range comparison |
[README](doc/README) |
repository file references |
[README](doc/README#L13) |
repository file line references |
GFM also recognizes certain cross-project references:
input | references |
---|---|
namespace/project#123 |
issue |
namespace/project!123 |
merge request |
namespace/project%123 |
project milestone |
namespace/project$123 |
snippet |
namespace/project@9ba12248 |
specific commit |
namespace/project@9ba12248...b19a04f5 |
commit range comparison |
namespace/project~"Some label" |
issues with given label |
It also has a shorthand version to reference other projects from the same namespace:
input | references |
---|---|
project#123 |
issue |
project!123 |
merge request |
project%123 |
project milestone |
project$123 |
snippet |
project@9ba12248 |
specific commit |
project@9ba12248...b19a04f5 |
commit range comparison |
project~"Some label" |
issues with given label |
Task Lists
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#task-lists
You can add task lists to issues, merge requests and comments. To create a task list, add a specially-formatted Markdown list, like so:
- [x] Completed task
- [ ] Incomplete task
- [ ] Sub-task 1
- [x] Sub-task 2
- [ ] Sub-task 3
Tasks formatted as ordered lists are supported as well:
1. [x] Completed task
1. [ ] Incomplete task
1. [ ] Sub-task 1
1. [x] Sub-task 2
Task lists can only be created in descriptions, not in titles. Task item state can be managed by editing the description's Markdown or by toggling the rendered check boxes.
Videos
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#videos
Image tags with a video extension are automatically converted to a video player.
The valid video extensions are .mp4
, .m4v
, .mov
, .webm
, and .ogv
.
Here's a sample video:
![Sample Video](img/markdown_video.mp4)
Here's a sample video:
Math
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#math
It is possible to have math written with the LaTeX syntax rendered using KaTeX.
Math written inside $``$
will be rendered inline with the text.
Math written inside triple back quotes, with the language declared as math
, will be rendered on a separate line.
Example:
This math is inline $`a^2+b^2=c^2`$.
This is on a separate line
```math
a^2+b^2=c^2
```
Becomes:
This is on a separate line
![](/kotovalexarian-likes-gitlab/gitlab-org--gitlab-foss/media/commit/f31aea1722c11263b17d01e4ac2f8ba214ffcd0f/doc/user/img/math_inline_sup_render_gfm.png)
Be advised that KaTeX only supports a subset of LaTeX.
Note: This also works for the asciidoctor
:stem: latexmath
. For details see the asciidoctor user manual.
Colors
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#colors
It is possible to have color written in HEX, RGB or HSL format rendered with a color indicator.
Color written inside backticks will be followed by a color "chip".
Examples:
`#F00`
`#F00A`
`#FF0000`
`#FF0000AA`
`RGB(0,255,0)`
`RGB(0%,100%,0%)`
`RGBA(0,255,0,0.7)`
`HSL(540,70%,50%)`
`HSLA(540,70%,50%,0.7)`
Becomes:
Supported formats:
- HEX:
`#RGB[A]`
or`#RRGGBB[AA]`
- RGB:
`RGB[A](R, G, B[, A])`
- HSL:
`HSL[A](H, S, L[, A])`
Mermaid
Introduced in GitLab 10.3.
If this is not rendered correctly, see https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#mermaid
It is possible to generate diagrams and flowcharts from text using Mermaid.
In order to generate a diagram or flowchart, you should write your text inside the mermaid
block.
Example:
```mermaid
graph TD;
A-->B;
A-->C;
B-->D;
C-->D;
```
Becomes:
![](/kotovalexarian-likes-gitlab/gitlab-org--gitlab-foss/media/commit/f31aea1722c11263b17d01e4ac2f8ba214ffcd0f/doc/user/img/mermaid_diagram_render_gfm.png)
For details see the Mermaid official page.
Standard Markdown
Headers
# H1
## H2
### H3
#### H4
##### H5
###### H6
Alternatively, for H1 and H2, an underline-ish style:
Alt-H1
======
Alt-H2
------
Header IDs and links
All Markdown-rendered headers automatically get IDs, except in comments.
On hover, a link to those IDs becomes visible to make it easier to copy the link to the header to give it to someone else.
The IDs are generated from the content of the header according to the following rules:
- All text is converted to lowercase.
- All non-word text (e.g., punctuation, HTML) is removed.
- All spaces are converted to hyphens.
- Two or more hyphens in a row are converted to one.
- If a header with the same ID has already been generated, a unique incrementing number is appended, starting at 1.
For example:
# This header has spaces in it
## This header has a :thumbsup: in it
# This header has Unicode in it: 한글
## This header has spaces in it
### This header has spaces in it
## This header has 3.5 in it (and parentheses)
Would generate the following link IDs:
this-header-has-spaces-in-it
this-header-has-a-in-it
this-header-has-unicode-in-it-한글
this-header-has-spaces-in-it
this-header-has-spaces-in-it-1
this-header-has-3-5-in-it-and-parentheses
Note that the Emoji processing happens before the header IDs are generated, so the Emoji is converted to an image which then gets removed from the ID.
Emphasis
Examples:
Emphasis, aka italics, with *asterisks* or _underscores_.
Strong emphasis, aka bold, with **asterisks** or __underscores__.
Combined emphasis with **asterisks and _underscores_**.
Strikethrough uses two tildes. ~~Scratch this.~~
Becomes:
Emphasis, aka italics, with asterisks or underscores.
Strong emphasis, aka bold, with asterisks or underscores.
Combined emphasis with asterisks and underscores.
Strikethrough uses two tildes. Scratch this.
Lists
Examples:
1. First ordered list item
2. Another item
* Unordered sub-list.
1. Actual numbers don't matter, just that it's a number
1. Ordered sub-list
4. And another item.
* Unordered list can use asterisks
- Or minuses
+ Or pluses
Becomes:
- First ordered list item
- Another item
- Unordered sub-list.
- Actual numbers don't matter, just that it's a number
- Ordered sub-list
- And another item.
- Unordered list can use asterisks
- Or minuses
- Or pluses
If a list item contains multiple paragraphs, each subsequent paragraph should be indented to the same level as the start of the list item text (Redcarpet: paragraph should be indented with four spaces.)
Example:
1. First ordered list item
Second paragraph of first item.
2. Another item
Becomes:
-
First ordered list item
Paragraph of first item.
-
Another item
If the paragraph of the first item is not indented with the proper number of spaces, the paragraph will appear outside the list, instead of properly indented under the list item.
Example:
1. First ordered list item
Paragraph of first item.
2. Another item
Becomes:
- First ordered list item
Paragraph of first item.
- Another item
Links
There are two ways to create links, inline-style and reference-style.
[I'm an inline-style link](https://www.google.com)
[I'm a reference-style link][Arbitrary case-insensitive reference text]
[I'm a relative reference to a repository file](LICENSE)
[I am an absolute reference within the repository](/doc/user/markdown.md)
[I link to the Milestones page](/../milestones)
[You can use numbers for reference-style link definitions][1]
Or leave it empty and use the [link text itself][]
Some text to show that the reference links can follow later.
[arbitrary case-insensitive reference text]: https://www.mozilla.org
[1]: http://slashdot.org
[link text itself]: https://www.reddit.com
Note: Relative links do not allow referencing project files in a wiki page or wiki page in a project file. The reason for this is that, in GitLab, wiki is always a separate Git repository. For example,
[I'm a reference-style link](style)
will point the link towikis/style
when the link is inside of a wiki markdown file.
Images
Examples:
Here's our logo (hover to see the title text):
Inline-style:
![alt text](img/markdown_logo.png)
Reference-style:
![alt text1][logo]
[logo]: img/markdown_logo.png
Becomes:
Here's our logo:
Inline-style:
Reference-style:
Blockquotes
Examples:
> Blockquotes are very handy in email to emulate reply text.
> This line is part of the same quote.
Quote break.
> This is a very long line that will still be quoted properly when it wraps. Oh boy let's keep writing to make sure this is long enough to actually wrap for everyone. Oh, you can *put* **Markdown** into a blockquote.
Becomes:
Blockquotes are very handy in email to emulate reply text. This line is part of the same quote.
Quote break.
This is a very long line that will still be quoted properly when it wraps. Oh boy let's keep writing to make sure this is long enough to actually wrap for everyone. Oh, you can put Markdown into a blockquote.
Inline HTML
You can also use raw HTML in your Markdown, and it'll mostly work pretty well.
See the documentation for HTML::Pipeline's SanitizationFilter class for the list of allowed HTML tags and attributes. In addition to the default SanitizationFilter
whitelist, GitLab allows span
, abbr
, details
and summary
elements.
Examples:
<dl>
<dt>Definition list</dt>
<dd>Is something people use sometimes.</dd>
<dt>Markdown in HTML</dt>
<dd>Does *not* work **very** well. Use HTML <em>tags</em>.</dd>
</dl>
Becomes:
- Definition list
- Is something people use sometimes.
- Markdown in HTML
- Does *not* work **very** well. Use HTML tags.
Details and Summary
Content can be collapsed using HTML's <details>
and <summary>
tags. This is especially useful for collapsing long logs so they take up less screen space.
Click me to collapse/fold.
These details will remain hidden until expanded.
PASTE LOGS HERE
Note: Markdown inside these tags is supported, as long as you have a blank line after the </summary>
tag and before the </details>
tag, as shown in the example. Redcarpet does not support Markdown inside these tags. You can work around this by using HTML, for example you can use <pre><code>
tags instead of code fences.
<details>
<summary>Click me to collapse/fold.</summary>
These details _will_ remain **hidden** until expanded.
PASTE LOGS HERE
</details>
Horizontal Rule
Examples:
Three or more...
---
Hyphens
***
Asterisks
___
Underscores
Becomes:
Three or more...
Hyphens
Asterisks
Underscores
Line Breaks
A good way to learn how line breaks work is to experiment and discover -- hit Enter once (i.e., insert one newline), then hit it twice (i.e., insert two newlines), see what happens. You'll soon learn to get what you want. The "Preview" tab is your friend.
Here are some things to try out:
Examples:
Here's a line for us to start with.
This line is separated from the one above by two newlines, so it will be a *separate paragraph*.
This line is also a separate paragraph, but...
This line is only separated by a single newline, so it *does not break* and just follows the previous line in the *same paragraph*.
This line is also a separate paragraph, and...
This line is *on its own line*, because the previous line ends with two spaces. (but still in the *same paragraph*)
spaces.
Becomes:
Here's a line for us to start with.
This line is separated from the one above by two newlines, so it will be a separate paragraph.
This line is also a separate paragraph, but... This line is only separated by a single newline, so it does not break and just follows the previous line in the same paragraph.
This line is also a separate paragraph, and...
This line is on its own line, because the previous line ends with two spaces. (but still in the same paragraph)
spaces.
Tables
Tables aren't part of the core Markdown spec, but they are part of GFM.
Example:
| header 1 | header 2 |
| -------- | -------- |
| cell 1 | cell 2 |
| cell 3 | cell 4 |
Becomes:
header 1 | header 2 |
---|---|
cell 1 | cell 2 |
cell 3 | cell 4 |
Note: The row of dashes between the table header and body must have at least three dashes in each column.
By including colons in the header row, you can align the text within that column.
Example:
| Left Aligned | Centered | Right Aligned | Left Aligned | Centered | Right Aligned |
| :----------- | :------: | ------------: | :----------- | :------: | ------------: |
| Cell 1 | Cell 2 | Cell 3 | Cell 4 | Cell 5 | Cell 6 |
| Cell 7 | Cell 8 | Cell 9 | Cell 10 | Cell 11 | Cell 12 |
Becomes:
Left Aligned | Centered | Right Aligned | Left Aligned | Centered | Right Aligned |
---|---|---|---|---|---|
Cell 1 | Cell 2 | Cell 3 | Cell 4 | Cell 5 | Cell 6 |
Cell 7 | Cell 8 | Cell 9 | Cell 10 | Cell 11 | Cell 12 |
Footnotes
Example:
You can add footnotes to your text as follows.[^2]
[^2]: This is my awesome footnote.
Becomes:
You can add footnotes to your text as follows.1
Superscripts / Subscripts
CommonMark and GFM currently do not support the superscript syntax ( x^2
) that Redcarpet does. You can use the standard HTML syntax for superscripts and subscripts.
The formula for water is H<sub>2</sub>O
while the equation for the theory of relativity is E = mc<sup>2</sup>.
The formula for water is H2O while the equation for the theory of relativity is E = mc2.
Wiki-specific Markdown
The following examples show how links inside wikis behave.
Wiki - Direct page link
A link which just includes the slug for a page will point to that page, at the base level of the wiki.
This snippet would link to a documentation
page at the root of your wiki:
[Link to Documentation](documentation)
Wiki - Direct file link
Links with a file extension point to that file, relative to the current page.
If this snippet was placed on a page at <your_wiki>/documentation/related
,
it would link to <your_wiki>/documentation/file.md
:
[Link to File](file.md)
Wiki - Hierarchical link
A link can be constructed relative to the current wiki page using ./<page>
,
../<page>
, etc.
-
If this snippet was placed on a page at
<your_wiki>/documentation/main
, it would link to<your_wiki>/documentation/related
:[Link to Related Page](./related)
-
If this snippet was placed on a page at
<your_wiki>/documentation/related/content
, it would link to<your_wiki>/documentation/main
:[Link to Related Page](../main)
-
If this snippet was placed on a page at
<your_wiki>/documentation/main
, it would link to<your_wiki>/documentation/related.md
:[Link to Related Page](./related.md)
-
If this snippet was placed on a page at
<your_wiki>/documentation/related/content
, it would link to<your_wiki>/documentation/main.md
:[Link to Related Page](../main.md)
Wiki - Root link
A link starting with a /
is relative to the wiki root.
-
This snippet links to
<wiki_root>/documentation
:[Link to Related Page](/documentation)
-
This snippet links to
<wiki_root>/miscellaneous.md
:[Link to Related Page](/miscellaneous.md)
References
- This document leveraged heavily from the Markdown-Cheatsheet.
- The original Markdown Syntax Guide at Daring Fireball is an excellent resource for a detailed explanation of standard markdown.
- The detailed specification for CommonMark can be found in the CommonMark Spec
- The CommonMark Dingus is a handy tool for testing CommonMark syntax.
-
This is my awesome footnote. ↩︎