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Preview of Live Resource Override

Live Resource Override by Sapan

Override JS, CSS, and API responses in your browser for safe debugging — without touching production.

Available on Firefox for Android™Available on Firefox for Android™
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Extension Metadata

About this extension
Live Resource Override lets you intercept and modify web resources directly in your browser — no proxy tools, no production deployments, no risk.

Key Features:
- Override JavaScript, CSS, HTML, and API responses on any website
- Redirect requests to local or remote files
- Modify HTTP response headers
- Block unwanted requests
- Inject custom JavaScript and CSS into any page
- Group rules by project with enable/disable toggles
- URL matching with contains, equals, wildcard, and regex patterns
- Domain and resource type filtering
- Import/export rule configurations
- Full editor UI for managing complex rule sets

Use Cases:
- Debug production issues safely without pushing code changes
- Test JavaScript fixes before deploying to a live environment
- Mock API responses for frontend development
- Block analytics or tracking scripts during testing
- Override CSS to prototype design changes in real-time

How It Works:
Create override rules that match URLs by pattern. When a matching request is detected, Live Resource Override intercepts it and applies your modification — whether that's replacing the response body, redirecting to a different file, injecting code, or modifying headers. All changes are session-only and never touch your production environment.

Built with Manifest V3 for security and performance. All data stays local in your browser — nothing is sent to external servers.

Permissions explained:
- Storage: Save your override rules locally
- DeclarativeNetRequest: Intercept and redirect network requests
- Tabs: Detect the active tab's URL for rule matching
- Host permissions: Apply overrides on any website you choose
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Permissions and data

Required permissions:

  • Block content on any page
  • Read your browsing history
  • Access browser tabs
  • Access your data for all websites

Optional permissions:

  • Access your data for all websites

Data collection:

  • The developer says this extension doesn't require data collection.
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More information
Add-on Links
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Version
1.0.0
Size
45.9 KB
Last updated
13 days ago (Mar 30, 2026)
Related Categories
  • Web Development
License
MIT License
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