JWT Decoder
Decode JWT tokens fast — header, payload, and claims (iat/exp/nbf) shown human-readable. Runs 100% in your browser, token never leaves your device.
Header
Payload
What is a JWT?
A JSON Web Token is the standard format for transmitting claims between client and server (auth, API access). Three parts:
<header>.<payload>.<signature>Security note
- This tool only decodes — it does NOT verify the signature. The payload is shown even if the signature is invalid.
- Never paste production JWTs containing sensitive data into any online decoder — including this one. Use dev/test tokens.
- Decoding runs 100% in your browser. Disconnect from the internet → it still works.
Who this is for
Fullstack/backend/devops engineers — debug JWT, format JSON/SQL, parse cURL, compute CIDR subnets, draft Mermaid diagrams, write conventional commits… Daily toolkit alongside your terminal and editor.
FAQ
Is my pasted code/token sent anywhere?
No. All TopDev dev tools run 100% client-side — JWT, SQL, JSON, cURL, regex… process in-browser. Disconnect to verify. Safe for internal tokens, production DB queries, API keys.
Does it work offline / install as a PWA?
Tools work offline after the first load. Installable PWA is on the roadmap — for now you can bookmark and use without internet.
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