Open toolkit

Dev Utilities

JWT Decoder

Paste a JWT (JSON Web Token) to instantly decode and view its header and payload as formatted JSON. Useful for debugging authentication tokens during development. This only decodes the token’s contents - it does not verify the signature, since that requires the secret or private key.

  • Files never leave your device
  • Runs entirely in your browser
  • Free, no account needed
Use JWT Decoder - free

Frequently asked questions

Does this verify the token’s signature?

No, verifying a signature requires the secret (HMAC) or public key (RSA/ECDSA) used to sign it - this tool only decodes the publicly visible header and payload.

Is my token sent to a server?

No, decoding happens entirely in your browser using standard Base64URL decoding - nothing is transmitted.

Why would decoding fail?

If the pasted text isn’t a valid JWT (three dot-separated Base64URL-encoded parts) or the payload isn’t valid JSON, decoding will show a clear error.

Decode a JWT instantly - free, private.

Open JWT Decoder
  • Files never leave your device
  • No upload required
  • No account needed
  • Unlimited use, always free

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Generate an MD5 or SHA-256 hash from text or a file.