Firefox Developer Tools Firefox Developer Tools A set of tools for inspecting and editing web code. Our team works closely with the community and is always happy to welcome new contributors. Get Involved Help build the last independent browser. Write code, fix bugs, make add-ons, and more. Contributor docs Good first bugs Speak Up Feedback makes us better. Tell us how we can improve the browser and Developer tools. File bugs Discourse forum Follow us on Mastodon or Twitter Join our chat rooms Mailing list Features Inspector Inspect and refine code to build pixel-perfect layouts. Learn more Console Track CSS, JavaScript, security and network issues. Learn more Debugger Powerful JavaScript debugger with support for your framework. Learn more Network Monitor network requests that can slow or block your site. Learn more Storage Add, modify and remove cache, cookies, databases and session data. Learn more Responsive Design Mode Test sites on emulated devices in your browser. Learn more Visual Editing Fine-tune animations, alignment and padding. Learn more Performance Unblock bottlenecks, streamline processes, optimize assets. Learn more Memory Find memory leaks and make your application zippy. Learn more Helpers VS Code Debugger for Firefox Debug your JavaScript code running in Firefox from VS Code. Learn more Firefox Developer Edition Looking for more than just Developer Tools? Check out the Firefox browser that is built specifically for developers and modern workflows. Learn more