JWT Decoder
This free JWT decoder tool takes any JSON Web Token you paste in and splits it into its readable header and payload JSON so you can inspect claims like sub, exp and iat. Decoding happens entirely on your device, so even tokens from production never leave your browser.
Decoding only — the signature is not verified. Nothing leaves your browser.
How to use JWT Decoder
- 1 Paste your JWT into the input box — it looks like three dot-separated segments.
- 2 Click Decode to expand the token.
- 3 Read the Header and Payload panels shown as formatted JSON.
- 4 Use the copy button on either panel to grab the JSON, or Clear to start over.
Frequently asked questions
Is my token sent to a server?
No. The token is split and Base64-decoded locally in your browser with JavaScript. Nothing is uploaded, so it is safe to inspect access tokens or other sensitive JWTs.
Does this verify the JWT signature?
No — this is a decoder only. It reads the header and payload but does not check the signature, so it never tells you whether a token is authentic or has been tampered with.
Why am I getting a 'not a valid JWT' error?
A JWT needs at least two dot-separated segments (header and payload). If your input is missing a dot or isn't a real token, the decoder can't split it and will flag it.
Can I read expired tokens?
Yes. Decoding works regardless of expiry — check the exp claim in the payload to see the expiry time yourself.