JWT Decoder
Decode and inspect the header, payload and signature of a JSON Web Token, entirely in your browser.
Privacy: This tool runs entirely in your browser. Your data never leaves your device and is never uploaded to any server.
A JWT must contain three dot-separated segments: header.payload.signature.
Frequently asked questions
What is a JWT?
A JSON Web Token (JWT) is a compact, URL-safe token made of three Base64URL-encoded parts: header, payload and signature.
Does this verify the token?
No. This tool decodes the header and payload for inspection only. It does not verify the signature or trustworthiness of a token.
Is my token uploaded?
No. Decoding happens locally in your browser, so the token never leaves your device.
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