Open Headers is a Chrome extension designed for developers and API testers looking to manage HTTP headers efficiently. This free tool provides comprehensive control over HTTP headers, allowing users to modify, add, and manage headers tailored for specific domains. With features like dynamic header sources that pull values from various inputs, real-time updates, and support for multiple domains, Open Headers streamlines the workflow for anyone needing to customize HTTP requests.

Key functionalities include smart formatting options for dynamic values, an import/export system for sharing configurations, and automatic validation of header values to ensure correctness. The extension operates seamlessly within the browser, monitoring requests and modifying headers on the fly, while an optional companion app provides access to local resources. Open Headers is ideal for API developers, QA engineers, and security professionals seeking to troubleshoot and optimize their web interactions.