Turn any webpage into clean Markdown.

## History

## Rise and divergence

## CommonMark

## Variants

## Examples

### GitHub Flavored Markdown

### Markdown Extra

Markdown [ 9 ]  is a  lightweight markup language  for creating  formatted text  using a  plain-text editor .  John Gruber  created Markdown in 2004 as an easy-to-read  markup language . [ 9 ]  Markdown is widely used for  blogging ,  instant messaging , and  large language models , [ 10 ]  and also used elsewhere in  online forums ,  collaborative software ,  documentation  pages, and  readme files .

The initial description of Markdown [ 11 ]  contained ambiguities and raised unanswered questions, causing implementations to both intentionally and accidentally diverge from the original version. This was addressed in 2014 when long-standing Markdown contributors released  CommonMark , an unambiguous specification and test suite for Markdown. [ 12 ] [ better   source   needed ]

Markdown was inspired by pre-existing  conventions  for marking up  plain text  in  email  and  usenet  posts, [ 13 ]  such as the earlier markup languages  setext  ( c.   1992 ),  Textile  ( c.   2002 ), and  reStructuredText  ( c.   2002 ). [ 9 ]

In 2002,  Aaron Swartz  created  atx  and referred to it as "the true structured text format". Gruber created the Markdown language in 2004 with Swartz as his "sounding board". [ 14 ]  The goal of the language was to enable people "to write using an easy-to-read and easy-to-write plain text format, optionally convert it to structurally valid  XHTML  (or  HTML )". [ 5 ]

Another key design goal was  readability , that the language be readable as-is, without looking like it has been marked up with tags or formatting instructions, [ 9 ]  unlike text formatted with "heavier"  markup languages , such as  Rich Text Format  (RTF), HTML, or even  wikitext , each of which have obvious in-line tags and formatting instructions which can make the text more difficult for humans to read. [ citation needed ]

Gruber wrote a  Perl  script,  Markdown.pl , which converts marked-up text input to valid,  well-formed  XHTML or HTML, encoding angle brackets ( < ,  > ) and  ampersands  ( & ), which would be misinterpreted as special characters in those languages. It can take the role of a standalone script, a plugin for  Blosxom  or  Movable Type , or of a text filter for  BBEdit . [ 5 ]

As Markdown's popularity grew rapidly, many Markdown  implementations  appeared, driven mostly by the need for additional features such as  tables ,  footnotes , definition lists, [ note 1 ]  and Markdown inside HTML blocks. [ citation needed ]

The behavior of some of these diverged from the reference implementation, as Markdown was only characterised by an informal  specification [ 17 ]  and a  Perl  implementation for conversion to HTML. [ citation needed ]

At the same time, a number of ambiguities in the informal specification had attracted attention. [ 18 ]  These issues spurred the creation of tools such as Babelmark [ 19 ] [ 20 ]  to compare the output of various implementations, [ 21 ]  and an effort by some developers of Markdown  parsers  for standardization. However, Gruber has argued that complete standardization would be a mistake: "Different sites (and people) have different needs. No one syntax would make all happy." [ 22 ]

Gruber avoided using curly braces in Markdown to unofficially reserve them for implementation-specific extensions. [ 23 ]

In 2012, a group of people, including  Jeff Atwood  and  John MacFarlane , launched what Atwood characterised as a standardization effort. [ 12 ]

A community website now aims to "document various tools and resources available to document authors and developers, as well as implementors of the various Markdown implementations". [ 26 ]

In September 2014, Gruber objected to the usage of "Markdown" in the name of this effort and it was rebranded as "CommonMark". [ 13 ] [ 27 ] [ 28 ]  CommonMark.org published several versions of a specification, reference implementation, test suite, and "[plans] to announce a finalized 1.0 spec and test suite in 2019". [ 29 ]  A finalized 1.0 spec has not been released, as major issues still remain unsolved. [ 30 ]

Nonetheless, several websites and projects have adopted CommonMark, including  Codeberg ,  Discourse ,  GitHub ,  GitLab ,  Reddit ,  Qt ,  Stack Exchange  ( Stack Overflow ), and  Swift .

In March 2016, two relevant informational Internet  RFCs  were published:

Websites including  Bitbucket ,  Diaspora ,  Discord , [ 32 ]   GitHub , [ 33 ]   OpenStreetMap ,  Reddit , [ 34 ]   SourceForge [ 35 ]  and  Stack Exchange [ 36 ]  use variants of Markdown to make discussions between users easier.

Depending on implementation, basic inline  HTML tags  may be supported. [ 37 ]

Italic text may be implemented by  _underscores_  or  *single-asterisks* . [ 38 ]

Many platforms implement spoiler formatting that hides text until hovered, clicked or tapped. The most common markup is ||spoiler|| used by Discord [ 39 ] , Telegram [ 40 ] [ 41 ] , various Matrix clients [ 42 ] , now defunct Guilded [ 43 ] , a forum called Flarum [ 44 ] , a NodeBB plugin [ 45 ] , the imageboard engine JSChan [ 46 ]  and possibly more.

GitHub  had been using its own variant of Markdown since as early as 2009, [ 47 ]  which added support for additional formatting such as tables and nesting  block content  inside list elements, as well as GitHub-specific features such as auto-linking references to commits, issues, usernames, etc.

In 2017, GitHub released a formal specification of its  GitHub Flavored Markdown  (GFM) that is based on  CommonMark . [ 33 ]  It is a  strict superset  of CommonMark, following its specification exactly except for tables,  strikethrough ,  autolinks  and task lists, which GFM adds as extensions. [ 48 ]

Accordingly, GitHub also changed the parser used on their sites, which required that some documents be changed. For instance, GFM now requires that the  hash symbol  that creates a heading be separated from the heading text by a space character.

Markdown Extra is a  lightweight markup language  based on Markdown implemented in  PHP  (originally),  Python  and  Ruby . [ 49 ]  It adds the following features that are not available with regular Markdown:

Markdown Extra is supported in some  content management systems  such as  Drupal , [ 50 ]   Grav (CMS) ,  Textpattern CMS [ 51 ]  and  TYPO3 . [ 52 ]

* John Gruber
* RFC   7763   –   " The text/markdown Media Type, " [ 2 ]   Informational.   Introduces  MIME  type  text/markdown .
* RFC   7764   –   " Guidance on Markdown: Design Philosophies, Stability Strategies, and Select Registrations, " [ 7 ]   Informational.   Discusses and registers the variants  MultiMarkdown ,  GitHub Flavored Markdown  (GFM),  Pandoc , and Markdown Extra (among others). [ 31 ]
* Markdown markup inside  HTML  blocks
* Elements with id/class attribute
* "Fenced code blocks" that span multiple lines of code
* Tables [ 49 ]
* Definition lists
* Footnotes
* Abbreviations