JWT.io
Decode, verify, and generate JSON Web Tokens in the browser. Paste a JWT and instantly see the header, payload, and signature. The go-to debugging tool for auth developers.
Not sure how to add JWT.io to your home screen? Step-by-step for Chrome, Safari, Firefox and Edge — it takes about ten seconds, and there is no app store involved.
Own JWT.io? Have us re-run this measurement — we open it in a real browser, cut the network, and send you what survived.
How to install JWT.io as a PWA
Screenshots
Are you the maker of JWT.io? Claim this listing →
More in Development Tools
Fast, offline, and free documentation browser for developers. Search 100+ docs in one web app including HTML, CSS, JavaScript, PHP, Ruby, Python, Go, C, C++, and many more.
The best regex debugger on the web. Real-time explanation, match highlighting, test strings, and a library of saved patterns. Supports PCRE2, JavaScript, Python, Golang regex. It explains each token in plain language beside the pattern, which turns debugging into reading rather than guessing.
Google's image compression tool — compare formats (WebP, AVIF, MozJPEG) side by side with live quality sliders. All processing is client-side. A must-have for web developers.
Drag-drop SVG optimizer with live preview. Uses SVGO under the hood — remove metadata, clean paths, reduce file size by 30-80%. Essential for frontend developers.
Check the bundle size of any npm package before installing it. Enter a package name, get instant size stats (minified + gzipped). A critical tool for keeping JS bundles lean.
Full browser-based IDE running Node.js via WebAssembly. Open GitHub repos instantly, run npm packages without installation, share working demos with a URL. No local setup needed.