ClassyBlocks — Custom CSS Classes, Design System & Preview for Gutenberg

Every Gutenberg block needs custom styling. And that's where your time disappears. You write the same CSS across 30 blocks. You switch between editor and customizer. One typo in a class name and the layout breaks. Your client calls because they can't change a button color. There's a faster way. ClassyBlocks gives you a design system command center right inside the WordPress block editor. Create your classes once — name them, write the rules, preview them live — and apply them anywhere with one click. What you get

• Your own class library — Create and organize CSS classes with full support for :hover, :focus, :active, and :visited. Each class documented and ready to use across your entire site.
• 9 built-in CSS frameworks — Bootstrap 5.3, Tailwind CSS 3.4, Foundation, Bulma, UIkit, Materialize, Pure CSS, Spectre, and Semantic UI. Toggle each on/off for editor and frontend independently.
• Live preview — See how every class looks in real time inside the block editor. No reloads, no switching tabs.
• One-click apply — Apply any class to any block with a single click. No typing class names manually.
• Pack Manager — Export and import complete class sets as packs. Share your design system across client sites in seconds.

Benefits that move the needle

• Ship sites 3x faster — Build your class library once. Apply across pages and posts in minutes, not hours.
• Kill support tickets — Clients style their own content using your pre-built classes. They stop calling you for every color change.
• Zero performance impact — Minimal stylesheet, zero JavaScript on the frontend. No bloat. No harm to Core Web Vitals.
• Works with every theme — Blocksy, GeneratePress, Astra, Twenty Twenty-Four. If it runs Gutenberg, ClassyBlocks works.

Trusted by agencies and freelancers Used by digital agencies managing 50+ client sites and solo freelancers who want a professional design workflow without the overhead. Need scroll-driven animations, priority support, and advanced features? Get ClassyBlocks Pro →

2.3.0

• Added WordPress.org SVN deploy automation via GitHub Actions.
• Updated screenshots and WordPress.org assets.
• Improved readme.txt description and formatting.
• Fixed Tested up to version consistency.

2.2.0

• Tailwind CSS now bundled locally (no external CDN dependency)
• Enhanced security: CSS sanitization, file upload validation, XSS fixes
• Improved localization: all JavaScript strings are translatable
• Replaced uniqid() with wp_generate_uuid4() for stronger IDs
• Added HTTP method checks to all AJAX handlers
• Various performance and security improvements

2.1.0

• Rebrand: Studio Immens CSS Classes → ClassyBlocks
• Introdotto ClassyBlocks Pro: animazioni scroll-driven, Pack Manager e funzionalità premium

1.2.1

• bug fix
• Added setting page options

1.1.1

• bug fix

1.1.0

• Added multiple set of framework CSS easly selectable from editor ( bootstrap, materialize, purecss, uikit, spectre, bulma, semantic )
• Added setting page

1.0.0

• Initial stable release
• Added core set of CSS utility classes
• Compatibility with Gutenberg and Blocksy, GeneratePress, and Astra themes