A fast text processor & publishing toolchain for converting AsciiDoc to HTML5, DocBook & more.

= Hello, AsciiDoc!
Doc Writer <>

An introduction to[AsciiDoc].

== First Section

* item 1
* item 2

puts "Hello, World!"

Asciidoctor is a fast text processor and publishing toolchain for converting AsciiDoc content to HTML5, DocBook, PDF, and other formats. Asciidoctor is written in Ruby, packaged and distributed as a gem to, and packaged for popular Linux distributions, including Fedora, Debian, Ubuntu, and Alpine. Asciidoctor can be run on the JVM using AsciidoctorJ and in all JavaScript environments using Asciidoctor.js. Asciidoctor is open source software and hosted on GitHub.


We want to recognize our generous sponsors, without whose support Asciidoctor would not be possible. Thank you sponsors for your dedication to improving the state of technical documentation!

Okta       OpenDevise

Major funding for Asciidoctor is provided by our Change Makers, Okta and OpenDevise, and our Strategy Sponsors, Khronos Group and Linda Roberts. Additional funding is provided by our Community Backers.

You can support this project by becoming a sponsor on OpenCollective.

The Big Picture

Asciidoctor reads content written in plain text, as shown in the panel on the left in the image below, and converts it to HTML5, as shown rendered in the right panel. Asciidoctor applies a default stylesheet to the HTML5 document to provide a pleasant out-of-the-box experience.

Preview of AsciiDoc source and corresponding rendered HTML

AsciiDoc Processing

Asciidoctor reads and parses text written in the AsciiDoc syntax, then feeds the parse tree to a set of built-in converters to produce HTML5, DocBook 5 (or 4.5) or man(ual) page output. You have the option of using your own converter or loading Tilt-supported templates to customize the generated output or produce additional formats.

Asciidoctor is a drop-in replacement for the original AsciiDoc Python processor ( The Asciidoctor test suite has > 2,000 tests to ensure compatibility with the AsciiDoc syntax.

In addition to the classic AsciiDoc syntax, Asciidoctor recognizes additional markup and formatting options, such as font-based icons (e.g., icon:fire[]) and UI elements (e.g., button:[Save]). Asciidoctor also offers a modern, responsive theme based on Foundation to style the HTML5 output.

Where Ruby goes, Asciidoctor follows

You can run Asciidoctor on the JVM using JRuby. To invoke the Asciidoctor API directly from Java and other JVM languages, use AsciidoctorJ. There are plugins available, based on AsciidoctorJ, that integrate the Asciidoctor processor into Apache Maven, Gradle or Javadoc builds.

Asciidoctor also runs in JavaScript. We use Opal to transcompile the Ruby source to JavaScript to produce Asciidoctor.js, a fully-functional version of Asciidoctor that works in any JavaScript environment, such as a web browser or Node.js. Asciidoctor.js is used to power the AsciiDoc preview extensions for Chrome, Atom, Brackets and other web-based tooling.


Asciidoctor works on Linux, macOS and Windows and requires one of the following implementations of Ruby:

  • Ruby (MRI/CRuby 1.8.7 - 2.5)

  • JRuby (1.7 in Ruby 1.8 and 1.9 modes, 9000)

  • Rubinius 2.2.x

  • Opal (JavaScript)

We welcome your help testing Asciidoctor on these and other platforms. Refer to the Contributing section to learn how to get involved.

If you’re using a non-English Windows environment, you may bump into an Encoding::UndefinedConversionError when invoking Asciidoctor. To solve this issue, we recommend changing the active code page in your console to UTF-8:

chcp 65001

Once you make this change, all your Unicode headaches will be behind you. If you’re using an IDE like Eclipse, make sure you set the encoding to UTF-8 there as well. Asciidoctor works best when you use UTF-8 everywhere.


Asciidoctor can be installed using (a) the gem install command, (b) Bundler, (c) package managers for popular Linux distributions, or (d) Homebrew for macOS.

The benefit of using a Linux package manager to install the gem is that it handles installing Ruby and the RubyGems library if those packages are not already installed on your machine. The drawback is that the package may not be available immediately after the release of the gem. If you need the latest version, you can always fallback to using the gem command.

(a) gem install

Open a terminal and type (excluding the leading $):

$ gem install asciidoctor

If you want to install a pre-release version (e.g., a release candidate), use:

$ gem install asciidoctor --pre
Upgrading your installation

If you have an earlier version of Asciidoctor installed, you can update it using:

$ gem update asciidoctor

If you install a new version of the gem using gem install instead of gem update, you’ll have multiple versions installed. If that’s the case, use the following gem command to remove the old versions:

$ gem cleanup asciidoctor

(b) Bundler

  1. Create a Gemfile in the root folder of your project (or the current directory)

  2. Add the asciidoctor gem to your Gemfile as follows:

    source ''
    gem 'asciidoctor'
    # or specify the version explicitly
    # gem 'asciidoctor', '1.5.7'
  3. Save the Gemfile

  4. Open a terminal and install the gem using:

    $ bundle

To upgrade the gem, specify the new version in the Gemfile and run bundle again. Using bundle update is not recommended as it will also update other gems, which may not be the desired result.

(c) Linux package managers

DNF (Fedora 21 or greater)

To install the gem on Fedora 21 or greater using dnf, open a terminal and type:

$ sudo dnf install -y asciidoctor

To upgrade the gem, use:

$ sudo dnf update -y asciidoctor
Your system may be configured to automatically update rpm packages, in which case no action is required by you to update the gem.

apt-get (Debian, Ubuntu, or Mint)

To install the gem on Debian, Ubuntu or Mint, open a terminal and type:

$ sudo apt-get install -y asciidoctor

To upgrade the gem, use:

$ sudo apt-get upgrade -y asciidoctor
Your system may be configured to automatically update deb packages, in which case no action is required by you to update the gem.

The version of Asciidoctor installed by the package manager (apt-get) may not match the latest release of Asciidoctor. Consult the package repository for your distribution to find out which version is packaged per distribution release.

You’re advised against using the gem update command to update a gem managed by the package manager. Doing so puts the system into an inconsistent state as the package manager can no longer track the files (which get installed under /usr/local). Simply put, system gems should only be managed by the package manager.

If you want to use a version of Asciidoctor that is newer than what is installed by the package manager, you should use RVM to install Ruby in your home directory (i.e., user space). Then, you can safely use the gem command to install or update the Asciidoctor gem. When using RVM, gems are installed in a location isolated from the system.

apk (Alpine Linux)

To install the gem on Alpine Linux, open a terminal and type:

$ sudo apk add asciidoctor

To upgrade the gem, use:

$ sudo apk add -u asciidoctor
Your system may be configured to automatically update apk packages, in which case no action is required by you to update the gem.

(d) Homebrew (macOS)

You can use Homebrew to install Asciidoctor on macOS. If you haven’t yet installed Homebrew, follow the instructions at

Once Homebrew is installed, you can install the asciidoctor gem using the asciidoctor package. To do so, open a terminal and type:

$ brew install asciidoctor

To upgrade the gem, use:

$ brew update
$ brew upgrade asciidoctor
Homebrew installs the asciidoctor gem into an exclusive prefix that’s independent of system gems.


If the Asciidoctor gem installed successfully, the asciidoctor command line interface (CLI) will be available on your PATH. To verify it’s available, run the following in your terminal:

$ asciidoctor --version

You should see information about the Asciidoctor version and your Ruby environment printed in the terminal.

Asciidoctor 1.5.7 []
Runtime Environment (ruby 2.4.1p111 [x86_64-linux]) (lc:UTF-8 fs:UTF-8 in:- ex:UTF-8)

Asciidoctor also provides an API. The API is intended for integration with other Ruby software, such as Rails, Sinatra and GitHub, and other languages, such as Java (via AsciidoctorJ) and JavaScript (via Asciidoctor.js).

Command line interface (CLI)

The asciidoctor command allows you to invoke Asciidoctor from the command line (i.e., a terminal).

The following command converts the file README.adoc to HTML and saves the result to the file README.html in the same directory. The name of the generated HTML file is derived from the source file by changing its file extension to .html.

$ asciidoctor README.adoc

You can control the Asciidoctor processor by adding various flags and switches, which you can learn about using:

$ asciidoctor --help

For instance, to write the file to a different directory, use:

$ asciidoctor -D output README.adoc

The asciidoctor man page provides a complete reference of the command line interface.

Refer to the following resources to learn more about how to use the asciidoctor command.

Ruby API

To use Asciidoctor in your application, you first need to require the gem:

require 'asciidoctor'

You can then convert an AsciiDoc source file to an HTML file using:

Asciidoctor.convert_file 'README.adoc', to_file: true, safe: :safe
When using Asciidoctor via the API, the default safe mode is :secure. In secure mode, several core features are disabled, including the include directive. If you want to enable these features, you’ll need to explicitly set the safe mode to :server (recommended) or :safe.

You can also convert an AsciiDoc string to embeddable HTML (for inserting in an HTML page) using:

content = '_Zen_ in the art of writing[AsciiDoc].'
Asciidoctor.convert content, safe: :safe

If you want the full HTML document, enable the header_footer option as follows:

content = '_Zen_ in the art of writing[AsciiDoc].'
html = Asciidoctor.convert content, header_footer: true, safe: :safe

If you need access to the parsed document, you can split the conversion into discrete steps:

content = '_Zen_ in the art of writing[AsciiDoc].'
document = Asciidoctor.load content, header_footer: true, safe: :safe
puts document.doctitle
html = document.convert

Keep in mind that if you don’t like the output Asciidoctor produces, you can change it! Asciidoctor supports custom converters that can handle converting from the parsed document to the generated output.

One easy way to customize the output piecemeal is by using the template converter. The template converter allows you to supply a Tilt-supported template file to handle converting any node in the document.

However you go about it, you can have 100% control over the output. For more information about how to use the API or to customize the output, refer to the user manual.


In the spirit of free software, everyone is encouraged to help improve this project. If you discover errors or omissions in the source code, documentation, or website content, please don’t hesitate to submit an issue or open a pull request with a fix. New contributors are always welcome!

Here are some ways you can contribute:

  • by using prerelease (alpha, beta or preview) versions

  • by reporting bugs

  • by suggesting new features

  • by writing or editing documentation

  • by writing specifications

  • by writing code — No patch is too small.

    • fix typos

    • add comments

    • clean up inconsistent whitespace

    • write tests!

  • by refactoring code

  • by fixing issues

  • by reviewing patches

The Contributing guide provides information on how to create, style, and submit issues, feature requests, code, and documentation to the Asciidoctor Project.

Getting Help

The Asciidoctor project is developed to help you easily write and publish your content. But we can’t do it without your feedback! We encourage you to ask questions and discuss any aspects of the project on the discussion list, on Twitter or in the chat room.

Discussion list (Nabble)


#asciidoctor hashtag or @asciidoctor mention

Chat (Gitter)


The Asciidoctor organization on GitHub hosts the project’s source code, issue tracker, and sub-projects.

Copyright © 2012-2018 Dan Allen, Ryan Waldron and the Asciidoctor Project. Free use of this software is granted under the terms of the MIT License.

See the LICENSE file for details.


Asciidoctor is led by Dan Allen and Sarah White and has received contributions from many other individuals in Asciidoctor’s awesome community. The project was initiated in 2012 by Ryan Waldron and based on a prototype written by Nick Hengeveld.

AsciiDoc was started by Stuart Rackham and has received contributions from many other individuals in the AsciiDoc community.