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Crayon Syntax Highlighter

Supports multiple languages, themes, fonts, highlighting from a URL, local file or post text.


Written in PHP and jQuery. Crayon is a Wordpress plugin, but can be used in any PHP environment.


Tag Editor

The Tag Editor makes adding code, changing settings and all that much easier with a simple dialog. I'd recommend it over the manual approach, since you can fine-tune the Crayon after the editor generates it :)

Pre-formatted Tags

You can also use <pre class="attributes" title="something">...</pre> so that:

  • Disabling Crayon still presents the code as pre-formatted text and is readable
  • Enforces proper encoding of entities (< in HTML view and not <)
  • The code snippets are reusable with other syntax highlighters

The Tag Editor generates tags like these. Attributes names are separated from values by either : (default) or _. E.g. <pre class="lang:php theme:twilight mark:1,2-4" title="something">...</pre> You can optionally provide the following attributes:


Name Description Example
lang Specify a Language ID, these are the folders in the langs directory and appears in the list of Languages in Settings. lang="java"
url Load a file from the web or a local path. You give a relative local path instead of absolute (see Files). For languages with defined extensions (see Languages in Settings) you don't even need to provide the lang attribute, as this will be detected if your file ends with it, as in the example. url="" or url="java/"
title Give a title for your code snippet. Appears in the toolbar. title="Sample"
mark Mark some lines as important so they appear highlighted. You can specify single numbers, comma separted, a range, or a combination. mark="5-10,12"
range Specify the range of lines from the input code to use in the output. You can specify a single number or a single range. range="3-5", range="3"

Mixed Highlighting

You can even mix code together like on a real HTML page, by having <script>, <style> and <?php...?> tags all in a single Crayon and setting the language to HTML.


Language information is found here in the Wordpress Admin: Settings > Crayon > Languages > Show Languages You can customise and create new languages and define how to capture each element (keywords, comments, strings, etc.) with regular expressions. Languages are structured langs/lang-name/lang-name.txt. Take a look at langs/default/default.txt and check out the neat regex of the default/generic language. See the readme in langs/ for more information about the language file syntax.

You can add custom languages in wp-content/uploads/crayon-syntax-highlighter/languages with the same format as those in the plugin directory and they will remain after plugin updates.


Crayon comes with built-in Themes to style your code. See a sample of the current set of themes. Themes are structured themes/theme-name/theme-name.css. If you know CSS, take a look at themes/default/default.css to get an idea of how they work and how you can change/create them. The specification for CSS classes is here.

You can add custom themes in wp-content/uploads/crayon-syntax-highlighter/themes with the same format as those in the plugin directory and they will remain after plugin updates. This is where user themes are stored when you customise stock themes in the Theme Editor.


You can enable support for Crayon comments by adding TinyMCE to the comment box. Add this code at the end of your theme's functions.php file. This requires at least version 3.3 of Wordpress.

add_filter('comment_form_defaults', 'tinymce_comment_enable');
function tinymce_comment_enable ( $args ) {
    wp_editor('', 'comment', array('tinymce'));
    $args['comment_field'] = ob_get_clean();
    return $args;

Then enable these settings in Wordpress Admin > Settings > Crayon:

  • "Display the Tag Editor in any TinyMCE instances on the frontend (e.g. bbPress)"
  • "Allow Crayons inside comments"


Crayon comes translated in several languages already, and if yours is included it will translate Crayon given you've followed instructions about how to show Wordpress in Your Language. If Crayon doesn't support your language or you'd like to help improve it:

  • Download POEdit. Add .. to the source paths under catalog preferences, and crayon__, crayon_n and crayon_e under source keywords.
  • Update and start making translations.
  • Send the .po file to me at and give me your name and a URL to your blog for credit. Alternatively, fork this repo and make a push request :)


You can define fonts and font-sizes within Themes, but you can also override the theme's font with those inside fonts/ and also provide @font-face fonts just like in themes - it's just CSS after all.

You can add custom fonts in wp-content/uploads/crayon-syntax-highlighter/fonts with the same format as those in the plugin directory and they will remain after plugin updates.

Disable Highlighting

You can temporarily disable highlighting for a piece of code using the highlight="false" attribute. You can also prevent Crayon from touching any kind of tag by using the crayon="false" attribute. If using pre tags, put crayon:false in the class.


Crayon's CSS and JavaScript resources is already minified (see css and js).


Crayon is versatile so you can override global settings for individual Crayons with attributes. The Tag Editor lets you do all this using a simple dialog!

Setting Allowed Value Description
theme string ID of the theme to use
font string ID of the font to use
font-size number > 0 Custom font size in pixels
min-height/max-height number > 0 followed by px/% Minimum/maximum height in units
height number > 0 followed by px/% Height in units
min-width/max-width number > 0 followed by px/% Minimum/maximum width in units
width number > 0 followed by px/% Width in units
toolbar true/false/"always" Show or hide the toolbar. "always" shows always (without mouseover).
top-margin number >= 0 Top margin in pixels
bottom-margin number >= 0 Bottom margin in pixels
left-margin number >= 0 Left margin in pixels
right-margin number >= 0 Right margin in pixels
h-align "none/left/right/center" Horizontal alignment
float-enable true/false Allow floating elements to surround Crayon
toolbar-overlay true/false Overlay the toolbar on code rather than push it down when possible
toolbar-hide true/false Toggle the toolbar on single click when it is overlayed
toolbar-delay true/false Delay hiding the toolbar on MouseOut
show-title true/false Display the title when provided
show-lang "found/always/never" When to display the language.
striped true/false Display striped code lines
marking true/false Enable line marking for important lines
nums true/false Display line numbers by default
nums-toggle true/false Enable line number toggling
plain true/false Enable plain code. Disabling will also disable plain toggling and copy/paste which use the plain code.
crayon false Prevent from turning the tag into a Crayon.
highlight true/false Prevent from highlighting the code, treats it as plain text instead.
plain-toggle true/false Enable plain code toggling
show-plain-default true/false Show the plain code by default instead of the highlighted code
copy true/false Enable code copy/paste
popup true/false Enable opening code in a window
scroll true/false Show scrollbar on mouseover
tab-size number >= 0 Tab size
trim-whitespace true/false Trim the whitespace around the code
mixed true/false Enable mixed highlighting (multiple languages in code)
show_mixed true/false Show the mixed highlighting plus sign
start-line number >= 0 When to start line numbers from
fallback-lang string ID of the language to use when none is detected
local-path string Local path to load file from
touchscreen true/false Disable mouse gestures for touchscreen devices (eg. MouseOver)
disable-anim true/false Disable animations
runtime true/false Disable runtime stats
error-log true/false Log errors for individual Crayons
error-log-sys true/false Log system-wide errors
error-msg-show true/false Display custom message for errors
error-msg string The error message to show for errors
mixed true/false Allow mixed languages using delimiters and tags

Legacy Tags

Using the legacy tag [crayon attributes] some code [/crayon] is possible but I highly recommend using <pre> tags instead. You can also convert legacy tags automatically in the Wordpress settings screen.

Mini Tags

Using Mini Tags like [php]some code[/php] is supported but also deprecated in favour of <pre> tags.


Crayon is released under the GPLv3 licence. See license.txt.


Syntax Highlighter supporting multiple languages, themes, fonts, highlighting from a URL, local file or post text.







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