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JWT Decoder
Paste a JWT below to decode, validate, and verify locally in your browser.
Demo algorithm
>_ JSON Web Token (JWT)
JWT must not be empty.
Paste or generate a JWT to see decoded header and payload.
JWT signature verification (optional)
Verification uses the Web Crypto API in your browser only. Secrets and PEM keys are never uploaded.
▸About this tool
Decode and inspect JSON Web Tokens: view the header, payload claims, and expiration date. Runs entirely in your browser.
▸Privacy and details
Your files never leave your device.
Fast browser processing with no account required.
Optimized for desktop and mobile with accessible controls.
▸How to use
- Paste a JWT (three dot-separated Base64URL parts) into the input field.
- The header, payload, and signature sections decode automatically.
- Check the expiration status: the tool shows if the token has expired.
- Copy the decoded payload for use in your code or debugging.
▸Why use this tool
Debugging authentication issues requires quickly inspecting what a JWT actually contains. This tool decodes any JWT instantly without sending it to a server, making it safe to use with tokens from staging environments.