Style Engine lets you apply your own CSS and JavaScript rules to websites. Built for developers, designers, and power users who want precise UI control without touching server-side code.

Apply custom CSS and JavaScript to websites globally or per domain. Lightweight, local-only, and fully user-controlled.

Key features

Global rules: Apply CSS/JS to all websites (typography tweaks, accessibility improvements, debugging overlays).
Per-website rules: Domain-isolated rule sets with independent enable/disable controls.
SPA navigation support: CSS automatically re-applies on route changes; JavaScript re-run can be enabled in Settings.
Optional live preview: Live JavaScript preview while typing in the popup editor (can be disabled in Settings).
Backup & Restore: Export/import your full configuration safely with a local JSON backup.
Flexible feedback: Desktop notifications, inline feedback, or silent mode.
Multi-language interface: English, Spanish, German, French, Italian, Dutch, Polish, Portuguese, Turkish, and Russian.

Common use cases

Create custom dark mode rules for sites that don’t support it.
Hide intrusive UI elements (banners, promos, sticky bars) with a few selectors.
Automate repetitive tasks with small JavaScript snippets.
Normalize fonts, spacing, and layout for a consistent browsing experience.

Privacy & safety

No tracking: Style Engine does not collect browsing data or analytics.
Local-only: Your rules are stored locally in your browser.
User-controlled: The extension runs only the code you explicitly write and save.
No remote code: No external scripts are downloaded or executed.

Links

Website: https://glitchid.com/products/style-engine/
Documentation: https://glitchid.com/products/style-engine/documentation/
Privacy: https://glitchid.com/privacy/style-engine-privacy/
Terms: https://glitchid.com/terms/style-engine-terms/
Support: support@glitchid.com

Publisher: Glitchid

Glitchid

Published Edge add-on:

Style Engine – Custom CSS & JavaScript