Description
Simple Code Block Highlighter enhances the default WordPress code and preformatted blocks. It can show line numbers, add a copy-to-clipboard button, switch between light and dark display themes, and automatically color code blocks with bundled Highlight.js syntax highlighting.
The plugin uses the WordPress Settings API, validates and sanitizes saved options, escapes admin output, and avoids inline JavaScript-generated HTML for line numbers. Syntax highlighting is served from the plugin files and does not load a third-party CDN on visitor pages.
For setup help, read the Simple Code Block Highlighter guide.
Third-party Libraries
This plugin bundles Highlight.js 11.11.1 for syntax highlighting.
Highlight.js
Source: Highlight.js on GitHub
License: BSD 3-Clause
License file included at: assets/vendor/highlightjs/LICENSE
Screenshots
Frontend code block with syntax highlighting, line numbers, and copy button. 
Plugin settings page with display options.
Installation
- Upload the plugin folder to
/wp-content/plugins/simple-code-block-highlighter. - Activate the plugin from the WordPress Plugins screen.
- Go to Settings > Simple Code Block Highlighter to choose display options. Color Code Blocks is checked by default.
- Add a WordPress Code block, paste any code you like, and the plugin will work out of the box.
FAQ
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How do I use the plugin?
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Add a WordPress Code block (
<code>) in the editor, paste any code you like, and publish or preview the post. The plugin automatically detects the language and highlights the block out of the box. -
Where can I find setup instructions?
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Read the Simple Code Block Highlighter guide for full setup and usage instructions.
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Does this plugin store visitor data?
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No. The plugin only stores administrator-selected display settings in the WordPress options table.
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Does this plugin change the original post content?
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No. Code blocks are enhanced in the browser after the page loads. The saved post content is not modified.
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Does the plugin detect code automatically?
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Yes. The plugin auto-detects the code type every time, so no extra setup is needed.
Reviews
There are no reviews for this plugin.
Contributors & Developers
“Simple Code Block Highlighter” is open source software. The following people have contributed to this plugin.
Contributors
Translate “Simple Code Block Highlighter” into your language.
Interested in development?
Browse the code, check out the SVN repository, or subscribe to the development log by RSS.
Changelog
1.2.2
- Tested with the latest version of WordPress 7.0.
1.2.1
- Switched syntax highlighting to automatic language detection only.
- Updated settings instructions and kept Color Code Blocks enabled by default.
- Updated usage FAQ.
1.2.0
- Added bundled Highlight.js syntax highlighting for common languages.
- Added automatic language detection for every highlighted code block.
- Added a setting to enable or disable color code blocks.
1.1.0
- Hardened settings validation, sanitization, escaping, and capability checks.
- Removed unsafe JavaScript
innerHTMLline-number rendering. - Added cache-busted asset versions and cleaner copy-button behavior.
- Added GitHub-ready security, CI, ignore, and documentation files.
1.0
- Initial release.