ModHeader

ModHeader is a popular browser extension designed to help web developers and QA engineers modify HTTP request and response headers. It allows users to easily add, modify, or remove headers such as authorization, set-cookie, and custom headers, directly within their browser. This functionality is crucial for tasks like simulating different user environments, testing API endpoints, debugging web applications, and verifying security policies. The extension streamlines the development workflow by enabling quick changes to header values without needing to alter server-side code or proxy configurations. It's particularly useful for testing various scenarios like different IP addresses, locales, CORS issues, and feature flags. By providing granular control over HTTP headers, ModHeader helps in faster debugging, reducing the time spent on identifying and fixing header-related issues, and ultimately minimizing production bugs. Beyond header modification, ModHeader also offers related tools like a header tester to inspect current request/response headers, and editors for Content-Security-Policy (CSP) and Permissions-Policy headers. These additional tools further empower developers to ensure web application security and functionality.