Python-Markdown Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning. See the Contributing Guide for details.



  • Fixed links to source code on GitHub from the documentation (#1453).

[3.6] – 2024-03-14


Refactor TOC Sanitation

  • All postprocessors are now run on heading content.
  • Footnote references are now stripped from heading content. Fixes #660.
  • A more robust striptags is provided to convert headings to plain text. Unlike, the markupsafe implementation, HTML entities are not unescaped.
  • The plain text name, rich html, and unescaped raw data-toc-label are saved to toc_tokens, allowing users to access the full rich text content of the headings directly from toc_tokens.
  • The value of data-toc-label is sanitized separate from heading content before being written to name. This fixes a bug which allowed markup through in certain circumstances. To access the raw unsanitized data, retrieve the value from token['data-toc-label'] directly.
  • An html.unescape call is made just prior to calling slugify so that slugify only operates on Unicode characters. Note that html.unescape is not run on name, html, or data-toc-label.
  • The functions get_name and stashedHTML2text defined in the toc extension are both deprecated. Instead, third party extensions should use some combination of the new functions run_postprocessors, render_inner_html and striptags.


  • Include scripts/*.py in the generated source tarballs (#1430).
  • Ensure lines after heading in loose list are properly detabbed (#1443).
  • Give smarty tree processor higher priority than toc (#1440).
  • Permit carets (^) and square brackets (]) but explicitly exclude backslashes (\) from abbreviations (#1444).
  • In attribute lists (attr_list, fenced_code), quoted attribute values are now allowed to contain curly braces (}) (#1414).

[3.5.2] – 2024-01-10


  • Fix type annotations for convertFile - it accepts only bytes-based buffers. Also remove legacy checks from Python 2 (#1400)
  • Remove legacy import needed only in Python 2 (#1403)
  • Fix typo that left the attribute AdmonitionProcessor.content_indent unset (#1404)
  • Fix edge-case crash in InlineProcessor with AtomicString (#1406).
  • Fix edge-case crash in codehilite with an empty code tag (#1405).
  • Improve and expand type annotations in the code base (#1401).
  • Fix handling of bogus comments (#1425).

[3.5.1] – 2023-10-31


  • Fix a performance problem with HTML extraction where large HTML input could trigger quadratic line counting behavior (#1392).
  • Improve and expand type annotations in the code base (#1394).

[3.5] – 2023-10-06


A new boolean option permalink_leading controls the position of the permanent link anchors generated with permalink. Setting permalink_leading to True will cause the links to be inserted at the start of the header, before any other header content. The default behavior for permalink is to append permanent links to the header, placing them after all other header content.


  • Add support for cPython version 3.12 (and PyPy 3.10) and drop support for Python version 3.7 (#1357).
  • Refactor changelog to use the format defined at
  • Update the list of empty HTML tags (#1353).
  • Add customizable TOC title class to TOC extension (#1293).
  • Add API documentation of the code base which is generated by mkdocstrings (#1220).


  • Fix a corner case in admonitions where if an indented code block was provided as the first block, the output would be malformed (#1329).

[3.4.4] – 2023-07-25


  • Add a special case for initial 's to smarty extension (#1305).
  • Unescape any backslash escaped inline raw HTML (#1358).
  • Unescape backslash escaped TOC token names (#1360).

[3.4.3] – 2023-03-23


  • Restore console script (#1327).

[3.4.2] – 2023-03-22


  • Officially support Python 3.11.
  • Improve standalone * and _ parsing (#1300).
  • Consider <html> HTML tag a block-level element (#1309).
  • Switch from to pyproject.toml.

[3.4.1] – 2022-07-15


  • Fix an import issue with importlib.util (#1274).

[3.4] – 2022-07-15


The tables extension now uses a style attribute instead of an align attribute for alignment.

The HTML4 spec specifically deprecates the use of the align attribute and it does not appear at all in the HTML5 spec. Therefore, by default, the tables extension will now use the style attribute (setting just the text-align property) in td and th blocks.

The former behavior is available by setting the use_align_attribute configuration option to True when enabling the extension.

For example, to configure the old align behavior:

from markdown.extensions.tables import TableExtension

markdown.markdown(src, extensions=[TableExtension(use_align_attribute=True)])

Backslash unescaping moved to Treeprocessor (#1131).

Unescaping backslash escapes has been moved to a Treeprocessor, which enables proper HTML escaping during serialization. However, it is recognized that various third-party extensions may be calling the old class at postprocessors.UnescapePostprocessor. Therefore, the old class remains in the code base, but has been deprecated and will be removed in a future release. The new class treeprocessors.UnescapeTreeprocessor should be used instead.

Previously deprecated objects have been removed

Various objects were deprecated in version 3.0 and began raising deprecation warnings (see the version 3.0 release notes for details). Any of those objects which remained in version 3.3 have been removed from the code base in version 3.4 and will now raise errors. The relevant objects are listed below.

Deprecated Object Replacement Object
markdown.version markdown.__version__
markdown.version_info markdown.__version_info__
markdown.util.etree xml.etree.ElementTree
markdown.util.string_type str
markdown.util.text_type str
markdown.util.int2str chr
markdown.util.iterrange range
markdown.util.isBlockLevel markdown.Markdown().is_block_level
markdown.util.Processor().markdown markdown.util.Processor().md
markdown.util.Registry().__setitem__ markdown.util.Registry().register
markdown.util.Registry().__delitem__ markdown.util.Registry().deregister
markdown.util.Registry().add markdown.util.Registry().register

In addition, the md_globals parameter of Markdown.extensions.Extension.extendMarkdown() is no longer recognized as a valid parameter and will raise an error if provided.


  • Some new configuration options have been added to the footnotes extension (#1218):

    • Small refactor of the BACKLINK_TITLE option; The use of format() instead of “old” %d formatter allows one to specify text without the need to have the number of the footnote in it (like footnotes on Wikipedia for example). The modification is backward compatible so no configuration change is required.

    • Addition of a new option SUPERSCRIPT_TEXT that allows one to specify a custom placeholder for the footnote itself in the text. Ex: [{}] will give <sup>[1]</sup>, ({}) will give <sup>(1)</sup>, or by default, the current behavior: <sup>1</sup>.

  • The Table of Contents extension now accepts a toc_class parameter which can be used to set the CSS class(es) on the <div> that contains the Table of Contents (#1224).

  • The CodeHilite extension now supports a pygments_formatter option that can be set to a custom formatter class (#1187).

    • If pygments_formatter is set to a string (ex: 'html'), Pygments’ default formatter by that name is used.
    • If pygments_formatter is set to a formatter class (or any callable which returns a formatter instance), then an instance of that class is used.

    The formatter class is now passed an additional option, lang_str, to denote the language of the code block (#1258). While Pygments’ built-in formatters will ignore the option, a custom formatter assigned to the pygments_formatter option can make use of the lang_str to include the code block’s language in the output.


  • Extension entry-points are only loaded if needed (#1216).
  • Added additional checks to the <pre><code> handling of PrettifyTreeprocessor (#1261, #1263).
  • Fix XML deprecation warnings.

[3.3.7] – 2022-05-05


  • Disallow square brackets in reference link ids (#1209).
  • Retain configured pygments_style after first code block (#1240).
  • Ensure fenced code attributes are properly escaped (#1247).

[3.3.6] – 2021-11-17


[3.3.5] – 2021-11-16


  • Make the slugify_unicode function not remove diacritical marks (#1118).
  • Fix [toc] detection when used with nl2br extension (#1160).
  • Re-use compiled regex for block level checks (#1169).
  • Don’t process shebangs in fenced code blocks when using CodeHilite (#1156).
  • Improve email address validation for Automatic Links (#1165).
  • Ensure <summary> tags are parsed correctly (#1079).
  • Support Python 3.10 (#1124).

[3.3.4] – 2021-02-24


  • Properly parse unclosed tags in code spans (#1066).
  • Properly parse processing instructions in md_in_html (#1070).
  • Properly parse code spans in md_in_html (#1069).
  • Preserve text immediately before an admonition (#1092).
  • Simplified regex for HTML placeholders (#928) addressing (#932).
  • Ensure permalinks and anchorlinks are not restricted by toc_depth (#1107).
  • Fix corner cases with lists under admonitions (#1102).

[3.3.3] – 2020-10-25


  • Unify all block-level tags (#1047).
  • Fix issue where some empty elements would have text rendered as None when using md_in_html (#1049).
  • Avoid catastrophic backtracking in hr regex (#1055).
  • Fix hr HTML handling (#1053).

[3.3.2] – 2020-10-19


  • Properly parse inline HTML in md_in_html (#1040 & #1045).
  • Avoid crashing when md_in_html fails (#1040).

[3.3.1] – 2020-10-12


  • Correctly parse raw script and style tags (#1036).
  • Ensure consistent class handling by fenced_code and codehilite (#1032).

[3.3] – 2020-10-06


The prefix language- is now prepended to all language classes by default on code blocks.

The HTML5 spec recommends that the class defining the language of a code block be prefixed with language-. Therefore, by default, both the fenced_code and codehilite extensions now prepend the prefix when code highlighting is disabled.

If you have previously been including the prefix manually in your fenced code blocks, then you will not want a second instance of the prefix. Similarly, if you are using a third party syntax highlighting tool which does not recognize the prefix, or requires a different prefix, then you will want to redefine the prefix globally using the lang_prefix configuration option of either the fenced_code or codehilite extensions.

For example, to configure fenced_code to not apply any prefix (the previous behavior), set the option to an empty string:

from markdown.extensions.fenced_code import FencedCodeExtension

markdown.markdown(src, extensions=[FencedCodeExtension(lang_prefix='')])


When code highlighting is enabled, the output from Pygments is used unaltered. Currently, Pygments does not provide an option to include the language class in the output, let alone prefix it. Therefore, any language prefix is only applied when syntax highlighting is disabled.

Attribute Lists are more strict (#898).

Empty curly braces are now completely ignored by the Attribute List extension. Previously, the extension would recognize them as attribute lists and remove them from the document. Therefore, it is no longer necessary to backslash escape a set of curly braces which are empty or only contain whitespace.

Despite not being documented, previously an attribute list could be defined anywhere within a table cell and get applied to the cell (<td> element). Now the attribute list must be defined at the end of the cell content and must be separated from the rest of the content by at least one space. This makes it easy to differentiate between attribute lists defined on inline elements within a cell and the attribute list for the cell itself. It is also more consistent with how attribute lists are defined on other types of elements.

The extension has also added support for defining attribute lists on table header cells (<th> elements) in the same manner as data cells (<td> elements).

In addition, the documentation for the extensions received an overhaul. The features (#987) and limitations (#965) of the extension are now fully documented.


  • All Pygments’ options are now available for syntax highlighting (#816).

    • The Codehilite extension now accepts any options which Pygments supports as global configuration settings on the extension.
    • Fenced Code Blocks will accept any of the same options on individual code blocks.
    • Any of the previously supported aliases to Pygments’ options continue to be supported at this time. However, it is recommended that the Pygments option names be used directly to ensure continued compatibility in the future.
  • Fenced Code Blocks now work with Attribute Lists when syntax highlighting is disabled. Any random HTML attribute can be defined and set on the <code> tag of fenced code blocks when the attr_list extension is enabled (#816).

  • The HTML parser has been completely replaced. The new HTML parser is built on Python’s html.parser.HTMLParser, which alleviates various bugs and simplify maintenance of the code (#803, #830).

  • The Markdown in HTML extension has been rebuilt on the new HTML Parser, which drastically simplifies it. Note that raw HTML elements with a markdown attribute defined are now converted to ElementTree Elements and are rendered by the serializer. Various bugs have been fixed (#803, #595, #780, and #1012).

  • Link reference parsing, abbreviation reference parsing and footnote reference parsing has all been moved from preprocessors to blockprocessors, which allows them to be nested within other block level elements. Specifically, this change was necessary to maintain the current behavior in the rebuilt Markdown in HTML extension. A few random edge-case bugs (see the included tests) were resolved in the process (#803).

  • An alternate function markdown.extensions.headerid.slugify_unicode has been included with the Table of Contents extension which supports Unicode characters in table of contents slugs. The old markdown.extensions.headerid.slugify method which removes non-ASCII characters remains the default. Import and pass markdown.extensions.headerid.slugify_unicode to the slugify configuration option to use the new behavior.

  • Support was added for Python 3.9 and dropped for Python 3.5.


  • Document how to pass configuration options to Extra (#1019).
  • Fix HR which follows strong em (#897).
  • Support short reference image links (#894).
  • Avoid a RecursionError from deeply nested blockquotes (#799).
  • Fix issues with complex emphasis (#979).
  • Fix unescaping of HTML characters <> in CodeHilite (#990).
  • Fix complex scenarios involving lists and admonitions (#1004).
  • Fix complex scenarios with nested ordered and unordered lists in a definition list (#918).

[3.2.2] – 2020-05-08


  • Add checklinks tox environment to ensure all links in documentation are good.
  • Refactor extension API documentation (#729).
  • Load entry_points (for extensions) only once using importlib.metadata.
  • Do not double escape entities in TOC.
  • Correctly report if an extension raises a TypeError (#939).
  • Raise a KeyError when attempting to delete a nonexistent key from the extension registry (#939).
  • Remove import of packaging (or pkg_resources fallback) entirely.
  • Remove setuptools as a run-time dependency (install_required).

[3.2.1] – 2020-02-12


  • The name property in toc_tokens from the TOC extension now escapes HTML special characters (<, >, and &).

[3.2] – 2020-02-07


Drop support for Python 2.7

Python 2.7 reaches end-of-life on 2020-01-01 and Python-Markdown 3.2 has dropped support for it. Please upgrade to Python 3, or use Python-Markdown 3.1.

em and strong inline processor changes

In order to fix issue #792, em/strong inline processors were refactored. This translated into removing many of the existing inline processors that handled this logic:

  • em_strong
  • strong
  • emphasis
  • strong2
  • emphasis

These processors were replaced with two new ones:

  • em_strong
  • em_strong2

The legacy_em extension was also modified with new, refactored logic and simply overrides the em_strong2 inline processor.

CodeHilite now always wraps with <code> tags

Before, the HTML generated by CodeHilite looked like: - <pre><code>foo = 'bar'</code></pre> if you were not using Pygments. - <pre>foo = 'bar'</pre> if you were using Pygments.

To make the cases more consistent (and adhere to many Markdown specifications and HTML code block markup suggestions), CodeHilite will now always additionally wrap code with <code> tags. See #862 for more details.

This change does not alter the Python-Markdown API, but users relying on the old markup will find their output now changed.

Internally, this change relies on the Pygments 2.4, so you must be using at least that version to see this effect. Users with earlier Pygments versions will continue to see the old behavior.

markdown.util.etree deprecated

Previously, Python-Markdown was using either the xml.etree.cElementTree module or the xml.etree.ElementTree module, based on their availability. In modern Python versions, the former is a deprecated alias for the latter. Thus, the compatibility layer is deprecated and extensions are advised to use xml.etree.ElementTree directly. Importing markdown.util.etree will raise a DeprecationWarning beginning in version 3.2 and may be removed in a future release.

Therefore, extension developers are encouraged to replace from markdown.util import etree with import xml.etree.ElementTree as etree in their code.


  • Some new configuration options have been added to the toc extension:

    • The anchorlink_class and permalink_class options allow class(es) to be assigned to the anchorlink and permalink respectively. This allows using icon fonts from CSS for the links. Therefore, an empty string passed to permalink now generates an empty permalink. Previously no permalink would have been generated. (#776)

    • The permalink_title option allows the title attribute of a permalink to be set to something other than the default English string Permanent link. (#877)

  • Document thread safety (#812).

  • Markdown parsing in HTML has been exposed via a separate extension called md_in_html.

  • Add support for Python 3.8.


  • HTML tag placeholders are no longer included in .toc_tokens (#899).
  • Unescape backslash-escaped characters in TOC ids (#864).
  • Refactor bold and italic logic in order to solve complex nesting issues (#792).
  • Always wrap CodeHilite code in code tags (#862).

[3.1.1] – 2019-05-20


  • Fixed import failure in when the source directory is not on sys.path (#823).
  • Prefer public packaging module to pkg_resources’ private copy of it (#825).

[3.1] – 2019-03-25


markdown.version and markdown.version_info deprecated

Historically, version numbers were acquired via the attributes markdown.version and markdown.version_info. As of 3.0, a more standardized approach is being followed and versions are acquired via the markdown.__version__ and markdown.__version_info__ attributes. As of 3.1 the legacy attributes will raise a DeprecationWarning if they are accessed. In a future release the legacy attributes will be removed.


  • A Contributing Guide has been added (#732).

  • A new configuration option to set the footnote separator has been added. Also, the rel and rev attributes have been removed from footnotes as they are not valid in HTML5. The refs and backrefs classes already exist and serve the same purpose (#723).

  • A new option for toc_depth to set not only the bottom section level, but also the top section level. A string consisting of two digits separated by a hyphen in between ("2-5"), defines the top (t) and the bottom (b) (<ht>..<hb>). A single integer still defines the bottom section level (<h1>..<hb>) only. (#787).


  • Update CLI to support PyYAML 5.1.
  • Overlapping raw HTML matches no longer leave placeholders behind (#458).
  • Emphasis patterns now recognize newline characters as whitespace (#783).
  • Version format had been updated to be PEP 440 compliant (#736).
  • Block level elements are defined per instance, not as class attributes (#731).
  • Double escaping of block code has been eliminated (#725).
  • Problems with newlines in references has been fixed (#742).
  • Escaped # are now handled in header syntax (#762).

[3.0.1] – 2018-09-28


  • Brought back the version and version_info variables (#709).
  • Added support for hexadecimal HTML entities (#712).

[3.0] – 2018-09-21


enable_attributes keyword deprecated

The enable_attributes keyword is deprecated in version 3.0 and will be ignored. Previously the keyword was True by default and enabled an undocumented way to define attributes on document elements. The feature has been removed from version 3.0. As most users did not use the undocumented feature, it should not affect most users. For the few who did use the feature, it can be enabled by using the Legacy Attributes extension.

smart_emphasis keyword and smart_strong extension deprecated

The smart_emphasis keyword is deprecated in version 3.0 and will be ignored. Previously the keyword was True by default and caused the parser to ignore middle-word emphasis. Additionally, the optional smart_strong extension provided the same behavior for strong emphasis. Both of those features are now part of the default behavior, and the Legacy Emphasis extension is available to disable that behavior.

output_formats simplified to html and xhtml.

The output_formats keyword now only accepts two options: html and xhtml Note that if (x)html1, (x)html4 or (x)html5 are passed in, the number is stripped and ignored.

safe_mode and html_replacement_text keywords deprecated

Both safe_mode and the associated html_replacement_text keywords are deprecated in version 3.0 and will be ignored. The so-called “safe mode” was never actually “safe” which has resulted in many people having a false sense of security when using it. As an alternative, the developers of Python-Markdown recommend that any untrusted content be passed through an HTML sanitizer (like Bleach) after being converted to HTML by markdown. In fact, Bleach Whitelist provides a curated list of tags, attributes, and styles suitable for filtering user-provided HTML using bleach.

If your code previously looked like this:

html = markdown.markdown(text, safe_mode=True)

Then it is recommended that you change your code to read something like this:

import bleach
from bleach_whitelist import markdown_tags, markdown_attrs
html = bleach.clean(markdown.markdown(text), markdown_tags, markdown_attrs)

If you are not interested in sanitizing untrusted text, but simply desire to escape raw HTML, then that can be accomplished through an extension which removes HTML parsing:

from markdown.extensions import Extension

class EscapeHtml(Extension):
    def extendMarkdown(self, md):

html = markdown.markdown(text, extensions=[EscapeHtml()])

As the HTML would not be parsed with the above Extension, then the serializer will escape the raw HTML, which is exactly what happened in previous versions with safe_mode="escape".

Positional arguments deprecated

Positional arguments on the markdown.Markdown() class are deprecated as are all except the text argument on the markdown.markdown() wrapper function. Using positional arguments will raise an error. Only keyword arguments should be used. For example, if your code previously looked like this:

html = markdown.markdown(text, [SomeExtension()])

Then it is recommended that you change it to read something like this:

html = markdown.markdown(text, extensions=[SomeExtension()])


This change is being made as a result of deprecating "safe_mode" as the safe_mode argument was one of the positional arguments. When that argument is removed, the two arguments following it will no longer be at the correct position. It is recommended that you always use keywords when they are supported for this reason.

Extension name behavior has changed

In previous versions of Python-Markdown, the built-in extensions received special status and did not require the full path to be provided. Additionally, third party extensions whose name started with "mdx_" received the same special treatment. This is no longer the case.

Support has been added for extensions to define an entry point. An entry point is a string name which can be used to point to an Extension class. The built-in extensions now have entry points which match the old short names. And any third-party extensions which define entry points can now get the same behavior. See the documentation for each specific extension to find the assigned name.

If an extension does not define an entry point, then the full path to the extension must be used. See the documentation for a full explanation of the current behavior.

Extension configuration as part of extension name deprecated

The previously documented method of appending the extension configuration options as a string to the extension name is deprecated and will raise an error. The extension_configs keyword should be used instead. See the documentation for a full explanation of the current behavior.

HeaderId extension deprecated

The HeaderId Extension is deprecated and will raise an error if specified. Use the Table of Contents Extension instead, which offers most of the features of the HeaderId Extension and more (support for meta data is missing).

Extension authors who have been using the slugify and unique functions defined in the HeaderId Extension should note that those functions are now defined in the Table of Contents extension and should adjust their import statements accordingly (from markdown.extensions.toc import slugify, unique).

Homegrown OrderedDict has been replaced with a purpose-built Registry

All processors and patterns now get “registered” to a Registry. A backwards compatible shim is included so that existing simple extensions should continue to work. A DeprecationWarning will be raised for any code which calls the old API.

Markdown class instance references.

Previously, instances of the Markdown class were represented as any one of md, md_instance, or markdown. This inconsistency made it difficult when developing extensions, or just maintaining the existing code. Now, all instances are consistently represented as md.

The old attributes on class instances still exist, but raise a DeprecationWarning when accessed. Also on classes where the instance was optional, the attribute always exists now and is simply None if no instance was provided (previously the attribute would not exist).

markdown.util.isBlockLevel deprecated

The markdown.util.isBlockLevel function is deprecated and will raise a DeprecationWarning. Instead, extensions should use the isBlockLevel method of the Markdown class instance. Additionally, a list of block level elements is defined in the block_level_elements attribute of the Markdown class which extensions can access to alter the list of elements which are treated as block level elements.

md_globals keyword deprecated from extension API

Previously, the extendMarkdown method of a markdown.extensions.Extension subclasses accepted an md_globals keyword, which contained the value returned by Python’s globals() built-in function. As all of the configuration is now held within the Markdown class instance, access to the globals is no longer necessary and any extensions which expect the keyword will raise a DeprecationWarning. A future release will raise an error.

markdown.version and markdown.version_info deprecated

Historically, version numbers were acquired via the attributes markdown.version and markdown.version_info. Moving forward, a more standardized approach is being followed and versions are acquired via the markdown.__version__ and markdown.__version_info__ attributes. The legacy attributes are still available to allow distinguishing versions between the legacy Markdown 2.0 series and the Markdown 3.0 series, but in the future the legacy attributes will be removed.

Added new, more flexible InlineProcessor class

A new InlineProcessor class handles inline processing much better and allows for more flexibility. The new InlineProcessor classes no longer utilize unnecessary pretext and post-text captures. New class can accept the buffer that is being worked on and manually process the text without regular expressions and return new replacement bounds. This helps us to handle links in a better way and handle nested brackets and logic that is too much for regular expression.


  • A new testing framework is included as a part of the Markdown library, which can also be used by third party extensions.

  • A new toc_depth parameter has been added to the Table of Contents Extension.

  • A new toc_tokens attribute has been added to the Markdown class by the Table of Contents Extension, which contains the raw tokens used to build the Table of Contents. Users can use this to build their own custom Table of Contents rather than needing to parse the HTML available on the toc attribute of the Markdown class.

  • When the Table of Contents Extension is used in conjunction with the Attribute Lists Extension and a data-toc-label attribute is defined on a header, the content of the data-toc-label attribute is now used as the content of the Table of Contents item for that header.

  • Additional CSS class names can be appended to Admonitions.

Previous Releases

For information on prior releases, see their changelogs: