JWT Encoder / Decoder
JWTs are the standard format for API authentication tokens. This tool lets you paste a JWT to decode its header and payload, or build a JWT from scratch with your own header and payload JSON. Optionally provide a secret to sign or verify the HMAC-SHA256 signature.
Processed on your deviceNo signup required100% free
JWT Token
Decoded
Decoded JWT will appear here
Paste a token and click Decode
How to Use
- Choose Encode or Decode mode.
- For decoding: paste a JWT token and click Decode.
- For encoding: enter header and payload JSON, optionally add a secret for signing.
- View the decoded header, payload, and signature status.
- Copy the result with one click.
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Frequently Asked Questions
What algorithms are supported?
HMAC-SHA256 for signing/verification. The decoder can read any algorithm's header, but signature verification only works with HMAC-SHA256.
Can I decode a JWT without the secret?
Yes. You can always decode the header and payload without a secret. The secret is only needed to verify the signature.
Is this safe for production tokens?
This tool is for inspection and debugging. Never paste real production secrets into a browser tool.