ModHead

Chrome extension for modifying HTTP request and response headers

ModHead - Powerful HTTP Header Modifier ModHead is a Chrome extension that allows you to dynamically modify HTTP request headers based on user-defined rules. Whether you're a developer testing APIs, debugging authentication flows, or working with CORS issues, ModHead provides a simple and intuitive interface to manage your HTTP headers. KEY FEATURES 🎯 Dynamic Header Modification • Add, modify, or remove HTTP request headers on the fly • Support for all HTTP request types (XHR, Fetch, main frames, scripts, etc.) • Real-time updates without browser restart 🌐 Flexible URL Pattern Matching • Three matching modes: startsWith, endsWith, equals • Multiple target domains per rule • Optional tab URL filtering for site-specific rules 🔄 Variables System • Define reusable variables for header values • Sensitive variable support with password masking • Use variables across multiple rules with ${variableName} syntax ⚡ Auto-Refresh Tokens • Automatically refresh authentication tokens (OAuth, JWT, etc.) • Support for multiple HTTP methods (GET, POST, PUT, PATCH, DELETE) • Custom headers and request body in refresh requests • Response transformation to extract specific values (JSON path, templates) 🎨 Modern User Interface • Clean, intuitive React-based interface • Dark theme support • Enable/disable rules with a single click • Visual feedback with toast notifications COMMON USE CASES ✓ Add API keys to development/testing requests ✓ Bearer token authentication ✓ CORS headers for local development ✓ Custom headers for debugging ✓ Multi-environment testing (dev/staging/prod) ✓ OAuth token auto-refresh ✓ JWT token management PERFECT FOR • Web Developers • API Developers • QA Engineers • DevOps Engineers • Security Testers • Anyone working with HTTP APIs PRIVACY & SECURITY ModHead runs entirely locally in your browser. No data is collected or sent to external servers. All rules and variables are stored locally using Chrome's storage API. BUILT WITH MODERN TECH • Manifest V3 (Chrome's latest extension architecture) • React & TypeScript • Chrome's declarativeNetRequest API • Open source on GitHub: https://github.com/HawkeyePierce89/ModHead