GitLab uses the Asciidoctor gem to convert AsciiDoc content to HTML5. Consult the Asciidoctor User Manual for a complete Asciidoctor reference.


Here’s a brief reference of the most commonly used AsciiDoc syntax. You can find the full documentation for the AsciiDoc syntax at


A normal paragraph.
Line breaks are not preserved.

Line comments, which are lines that start with //, are skipped:

// this is a comment

A blank line separates paragraphs.

A paragraph with the [%hardbreaks] option preserves line breaks:

This paragraph carries the `hardbreaks` option.
Notice how line breaks are now preserved.

An indented (literal) paragraph disables text formatting, preserves spaces and line breaks, and is displayed in a fixed-width font:

 This literal paragraph is indented with one space.
 As a consequence, *text formatting*, spaces,
 and lines breaks will be preserved.

Admonition paragraphs grab the reader’s attention:

  • NOTE: This is a brief reference, please read the full documentation at
  • TIP: Lists can be indented. Leading whitespace is not significant.

Text Formatting

Constrained (applied at word boundaries)

*strong importance* (aka bold)
_stress emphasis_ (aka italic)
`monospaced` (aka typewriter text)
"`double`" and '`single`' typographic quotes
+passthrough text+ (substitutions disabled)
`+literal text+` (monospaced with substitutions disabled)

Unconstrained (applied anywhere)



A long time ago in a galaxy far, far away...
(C) 1976 Arty Artisan
I believe I shall--no, actually I won't.


// where c=specialchars, q=quotes, a=attributes, r=replacements, m=macros, p=post_replacements, etc.
The European icon:flag[role=blue] is blue & contains pass:[************] arranged in a icon:circle-o[role=yellow].
The pass:c[->] operator is often referred to as the stabby lambda.
Since `pass:[++]` has strong priority in AsciiDoc, you can rewrite pass:c,a,r[C++ => C{pp}].
// activate stem support by adding `:stem:` to the document header
stem:[sqrt(4) = 2]


User-defined attributes

// define attributes in the document header
:name: value

You can download and install Asciidoctor {asciidoctor-version} from {url-gem}.
C{pp} is not required, only Ruby.
Use a leading backslash to output a word enclosed in curly braces, like \{name}.

Environment attributes

GitLab sets the following environment attributes:

Attribute Description
docname Root name of the source document (no leading path or file extension).
outfilesuffix File extension corresponding to the backend output (defaults to .adoc to make inter-document cross references work).[A webpage]
link:../path/to/file.txt[A local file]
xref:document.adoc[A sibling document][Email to say hello!]


[[idname,reference text]]
// or written using normal block attributes as `[#idname,reftext=reference text]`
A paragraph (or any block) with an anchor (aka ID) and reftext.

See <<idname>> or <<idname,optional text of internal link>>.

xref:document.adoc#idname[Jumps to anchor in another document].

This paragraph has a footnote.footnote:[This is the text of the footnote.]



* level 1
** level 2
*** level 3
**** level 4
***** etc.
* back at level 1
Attach a block or paragraph to a list item using a list continuation (which you can enclose in an open block).

.Some Authors
- Edgar Allen Poe
- Sheri S. Tepper
- Bill Bryson


. Step 1
. Step 2
.. Step 2a
.. Step 2b
. Step 3

.Remember your Roman numerals?
. is one
. is two
. is three


* [x] checked
* [ ] not checked


// enable callout bubbles by adding `:icons: font` to the document header
puts 'Hello, World!' # <1>
<1> Prints `Hello, World!` to the console.


first term:: description of first term
second term::
description of second term

Document Structure

= Document Title
Author Name <>
v1.0, 2019-01-01


= Document Title (Level 0)
== Level 1
=== Level 2
==== Level 3
===== Level 4
====== Level 5
== Back at Level 1



// define -a allow-uri-read to allow content to be read from URI

To guarantee good system performance and prevent malicious documents causing problems, GitLab enforces a maximum limit on the number of include directives processed in any one document. Currently a total of 32 documents can be included, a number that is inclusive of transitive dependencies.


open - a general-purpose content wrapper; useful for enclosing content to attach to a list item
// recognized types include CAUTION, IMPORTANT, NOTE, TIP, and WARNING
// enable admonition icons by setting `:icons: font` in the document header
admonition - a notice for the reader, ranging in severity from a tip to an alert
example - a demonstration of the concept being documented
.Toggle Me
collapsible - these details are revealed by clicking the title
sidebar - auxiliary content that can be read independently of the main content
literal - an exhibit that features program output
listing - an exhibit that features program input, source code, or the contents of a file
source - a listing that is embellished with (colorized) syntax highlighting
fenced code - a shorthand syntax for the source block
quote - a quotation or excerpt; attribution with title of source are optional
verse - a literary excerpt, often a poem; attribution with title of source are optional
pass - content passed directly to the output document; often raw HTML
// activate stem support by adding `:stem:` to the document header
x = y^2
comment - content which is not included in the output document


.Table Attributes
| Attribute Name | Values

| options
| header,footer,autowidth

| cols
| colspec[;colspec;...]

| grid
| all \| cols \| rows \| none

| frame
| all \| sides \| topbot \| none

| stripes
| all \| even \| odd \| none

| width
| (0%..100%)

| format
| psv {vbar} csv {vbar} dsv


It’s possible to have color written in HEX, RGB, or HSL format rendered with a color indicator. Supported formats (named colors are not supported):

  • HEX: `#RGB[A]` or `#RRGGBB[AA]`
  • RGB: `RGB[A](R, G, B[, A])`
  • HSL: `HSL[A](H, S, L[, A])`

Color written inside backticks is followed by a color “chip”:

- `#F00`
- `#F00A`
- `#FF0000`
- `#FF0000AA`
- `RGB(0,255,0)`
- `RGB(0%,100%,0%)`
- `RGBA(0,255,0,0.3)`
- `HSL(540,70%,50%)`
- `HSLA(540,70%,50%,0.3)`


To activate equation and formula support, set the stem attribute in the document’s header to latexmath. Equations and formulas are rendered using KaTeX:

:stem: latexmath

latexmath:[C = \alpha + \beta Y^{\gamma} + \epsilon]

sqrt(4) = 2

A matrix can be written as stem:[[[a,b\],[c,d\]\]((n),(k))].

Diagrams and flowcharts

It’s possible to generate diagrams and flowcharts from text in GitLab using Mermaid or PlantUML.


Introduced in GitLab 13.3.

Visit the official page for more details. If you’re new to using Mermaid or need help identifying issues in your Mermaid code, the Mermaid Live Editor is a helpful tool for creating and resolving issues within Mermaid diagrams.

In order to generate a diagram or flowchart, you should write your text inside the mermaid block:

graph LR
    A[Square Rect] -- Link text --> B((Circle))
    A --> C(Round Rect)
    B --> D{Rhombus}
    C --> D


Kroki supports more than a dozen diagram libraries. To make Kroki available in GitLab, a GitLab administrator needs to enable it first. Read more in the Kroki integration page.

Once Kroki is enabled, you can create a wide variety of diagrams in AsciiDoc and Markdown documents. Here’s an example using a GraphViz diagram:


digraph G {


digraph G {


To make PlantUML available in GitLab, a GitLab administrator needs to enable it first. Read more in PlantUML & GitLab.

Once enabled, you should write your text inside the plantuml block:

Bob -> Alice : hello


image::screenshot.png[block image,800,450]

Press image:reload.svg[reload,16,opts=interactive] to reload the page.





// thematic break (aka horizontal rule)
// page break