Skip to content


DETAILS: Tier: Free, Premium, Ultimate Offering:, Self-managed, GitLab Dedicated

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

You can use AsciiDoc in the following areas:

  • Wiki pages
  • AsciiDoc documents (.adoc or .asciidoc) inside repositories


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
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).

Links[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
***** level 5
* 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


NOTE: Wiki pages created with the AsciiDoc format are saved with the file extension .asciidoc. When working with AsciiDoc wiki pages, change the filename from .adoc to .asciidoc.


To guarantee good system performance and prevent malicious documents from causing problems, GitLab enforces a maximum limit on the number of include directives processed in any one document. By default, a document can have up to 32 include directives, which is inclusive of transitive dependencies. To customize the number of processed includes directives, change the application setting asciidoc_max_includes with the application settings API.

NOTE: The current maximum allowed value forasciidoc_max_includes is 64. If the value is too high might cause performance issues in some situations.

To use includes from separate pages or external URLs, enable the allow-uri-read in application settings.

// define application setting allow-uri-read to true to allow content to be read from URI


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)`

Equations and Formulas (STEM)

If you need to include Science, Technology, Engineering, and Math (STEM) expressions, 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.


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.

To generate a diagram or flowchart, enter your text in a 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.

After Kroki is enabled, you can create diagrams in AsciiDoc and Markdown documents. Here's an example using a GraphViz diagram:


digraph G {


digraph G {


PlantUML integration is enabled on To make PlantUML available in self-managed installation of GitLab, a GitLab administrator must enable it.

After PlantUML is enabled, enter your text in a plantuml block:

Bob -> Alice : hello


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

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


GitLab does not support embedding YouTube and Vimeo videos in AsciiDoc content. Use a standard AsciiDoc link:[Link text for the video]


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