Developer
JSON Formatter / Validator
Validate, format and compact JSON without uploading your input.
Open toolJWT Decoder
Inspect a compact JWT header and payload locally. Decoding does not verify the signature.
Maximum 200,000 characters. Input is not stored.
Ready. Use Ctrl/⌘ + Enter to run.
Completed and failed run counts are stored only on this device.
How to use this tool
Paste a three-part compact JWT. Read the explicit unverified warning with the decoded data.
Supported input and limits
No signature verification, trust decision, claim validation or encrypted JWE support. Never share private tokens. Maximum main input: 200,000 characters.
Frequently asked questions
Does my input leave my browser?
No. A local worker processes it; text and files are not uploaded or stored.
Is a decoded token valid or trusted?
No. Decoding only exposes its data. A server must verify its signature, issuer, audience and claims.
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