Upgrading to Highlight.js v11.0

Overview of Breaking Changes

Welcome to version 11.0. This a major release and therefore contains breaking changes. Below is a complete list of those such changes.

Built-in set of “Common” Languages

The default highlight.min.js build removes a few less popular grammars:

  • apache

  • http

  • nginx

  • properties

  • coffeescript

If you need any of these, you can always create a custom build.

Ref: https://github.com/highlightjs/highlight.js/issues/2848

Language Files

This would matter if you are requiring any of these files directly (via Node.js or CDN).

  • htmlbars has been removed. Use handlebars instead.

  • c-like has been removed. Use c, cpp, or arduino.

  • sql_more has been removed. Use sql instead or a more specific 3rd party grammar.

Language Aliases

This would matter if you are using these aliases.

  • php3,php4,php5, php6, php7, and php8 have been removed. Use php instead.

  • zsh has been removed. Use sh or bash instead.

  • freepascal, lazarus, lpr, and lpm removed. Use delphi instead.

You can of course re-register any of these aliases easily if necessary. For example to restore the PHP aliases:

hljs.registerAliases(["php3","php4","php5","php6","php7","php8"],{ languageName: "php" })

Styles and CSS

  • The default padding on .hljs element has been increased and is now 1em (it was 0.5em previously). If your design depends on the smaller spacing you may need to update your CSS to override.

  • schoolbook no longer has a custom lined background, it is solid color now. The old image and CSS can be found in the 10-stable branch if you wish to manually copy it into your project.

  • github includes significant changes to more properly match modern GitHub syntax highlighting. If you desire the old theme you can manually copy it into your project from the 10-stable branch.

  • github-gist has been removed in favor of github as GitHub and GitHub Gist have converged. If you desire the theme you can manually copy it into your project from the 10-stable branch.

  • The .hljs CSS selector is now further scoped. It now targets code.hljs (inline code) and pre code.hljs (code blocks). If you are using a different element you may need to update your CSS to reapply some styling.

  • All Base16 themes now live in the styles/base16 directory - this means some CSS files have moved. Please confirm themes you use reference the new locations.

Grammar Scopes

  • .meta-string removed/deprecated. Use .meta .string (a nested scope) instead. See meta-keyword.

  • .meta-keyword removed/deprecated. Use .meta .keyword (a nested scope) instead. See meta-keyword.

Behavioral changes

  • after:highlightElement plugin callback is now fired after the DOM has been updated, not before.

API changes

  • The option ignoreIllegals is now true by default (for highlight()). Previously it was false.

  • The highlight(language,code, ...args) API no longer accepts continuation as a 4th argument.

  • The highlight(language,code, ...args) API is deprecated (to be removed in 12.0).

The new call signature is highlight(code, {options}). (see docs)

Code using the old API:

// highlight(language, code, ignoreIllegals, continuation)
highlight("javascript", "var a = 5;", true)

…would be upgraded to the newer API as follows:

// highlight(code, {language, ignoreIllegals})
highlight("var a = 5;", {language: "javascript", ignoreIllegals: true})

The new API purposely does not support continuation as this is only intended for internal library usage.

  • initHighlighting() is deprecated (to be removed in 12.0).

  • initHighlightingOnLoad() is deprecated (to be removed in 12.0).

Use highlightAll() instead. (see docs) The old functions are now simply aliases of highlightAll(). The new function may be called before or after the DOM is loaded and should do the correct thing in all cases, replacing the need for the previous individual functions.

Note: highlightAll() does not guard against calling itself repeatedly as the previous functions did. Your code should be careful to avoid doing this.

  • highlightBlock() is deprecated (to be removed in 12.0).

Use highlightElement() instead. (see docs) This is merely a naming change.

Note: The object literal passed to the before:highlightElement callback now passes the element in the el key vs the block key.

Changes to Result Data
  • highlightAuto()’s second_best key has been renamed to secondBest

  • highlightElement()’s result now no longer includes a re key. Use the relevance key now.

  • highlight() renames some result keys to more clearly mark them as private: _top, _emitter, and _illegalBy. You should not depend on these keys as they are subject to change at any time.

  • The relevance key returned by highlight() is no longer guaranteed to be an even integer.

  • highlightElement now always tags blocks with a consistent language-[name] class

This behavior was inconsistent before. Sometimes [name] class would be added, sometimes the alias name would be added, something no class would be added. now language-[name] is always added. This also affects sublanguage span tags which now also include the language- prefix.

Feature Removal

  • HTML auto-passthru is now no longer included in core. Use a plugin instead. For a possible plugin please see #2889.

An example:

<pre><code class="lang-js">
var a = 4;
<span class="yellow">var a = 4;</span>

Unescaped HTML like this will now be ignored (stripped before highlighting) and a warning will be logged to the console. All HTML to be highlighted should be properly escaped to avoid potential HTML/JS injection attacks.

  • fixMarkup has been removed.

This function was deprecated in v10.2. It is not our goal to provide random string utilities. You may need to provide your own replacement Ref: #2534

  • CSS_NUMBER_MODE has been removed.

This rule was too broad for bring inclusion in core and has been removed.

  • lexemes mode attribute has been removed.

Use the new keywords.$pattern instead.


  keywords: "do.it start.now begin.later end.immediately"
  lexemes: /[a-z.]+/


  keywords: {
    $pattern: /[a-z.]+/
    keyword: "do.it start.now begin.later end.immediately",

This may required converting your keywords key into an object if it’s not already (as shown above).

  • endSameAsBegin mode attribute has been removed.

Use the new END_SAME_AS_BEGIN mode rule/function instead.

  • useBR configuration has been removed.

This configuration option was deprecated in v10.1. Use a plugin or preferably simply CSS white-space: pre. Ref: #2559

  • tabReplace configuration has been removed.

This configuration option was deprecated in v10.5. Use a plugin or pre-render content instead with desired spacing. Ref: #2874

Small Things

  • The regex utility join has been renamed to _eitherRewriteBackreferences (this has always been intended for internal use only)

Upgrading from Version 9.x

If you’re upgrading all the way from version 9 it may still be helpful to review all the breaking changes in version 10 as well: