ModHeader V3 by modheader.app

ModHeader V3 by modheader.app | Modify remove override useragent referer cookies headers for HTTP API requests

ModHeader — Modify HTTP Request & Response Headers ModHeader is a free Chrome extension for modifying HTTP request headers and response headers directly in your browser — no coding, no proxy setup, no server restarts. Built for developers, QA engineers, and API testers who need fast, reliable control over headers, cookies, and User-Agent strings while debugging and testing. Key Features ▸ Modify HTTP Headers Instantly — Add, edit, or remove custom request and response headers through a simple interface. Ideal for API testing, authentication token simulation, and header-based debugging. ▸ CORS Testing Made Easy — Inject Access-Control-Allow-Origin and other CORS headers to bypass cross-origin restrictions during local development. ▸ User-Agent Switcher — Change your User-Agent string to test how sites render across different browsers, devices, and operating systems, including custom UA strings. ▸ Multiple Header Profiles — Save separate profiles for dev, staging, and production environments, and switch between them in one click. ▸ Cookie Management — View, add, and modify cookies alongside header changes for complete request control. ▸ URL Filtering & Conditional Rules — Scope header changes to specific URLs, domains, or patterns so modifications only apply where intended. ▸ Import & Export Profiles — Share header configurations with your team via JSON, useful for collaborative QA and API testing workflows. ▸ Lightweight & Privacy-Focused — Requests only the permissions needed to function, with no unnecessary data collection. Who Uses ModHeader ▸ Web developers testing REST APIs and GraphQL endpoints ▸ QA engineers simulating different environments ▸ Developers debugging CORS, authentication, and session issues ▸ Teams testing responsive design via User-Agent switching ▸ Anyone needing quick, reliable HTTP header modification in Chrome Install ModHeader for simple, direct control over your HTTP headers, cookies, and User-Agent — right inside Chrome.