JWT Decoder
Paste a JWT to see the header and payload as readable JSON, plus human-readable issue and expiry times. This tool decodes only; it does not verify signatures.
Free Runs locally No signup
Paste a token to inspect it.
Decoding does not verify the signature. Treat tokens as secrets.
How to use it
1
Paste the token
Drop a JWT into the input box; the three segments are decoded separately.
2
Inspect the claims
Read iss, sub, aud, exp, nbf and iat in a readable format.
3
Copy a segment
Copy the decoded header or payload as formatted JSON.
Why use this tool
Readable claim times
exp, nbf and iat are shown as UTC dates and relative times.
Three-part breakdown
Header, payload and signature are displayed with their raw values.
Local and private
Tokens are decoded in your browser and never sent to a server.
Frequently asked questions
Does this verify the signature?
No. Decoding only reads the token contents. Signature verification requires the issuer key or secret and is not performed here.
Is it safe to paste a JWT?
Decoding happens locally, but treat tokens as secrets. Avoid pasting production tokens into any online tool.
What do exp, nbf and iat mean?
exp is the expiry time, nbf is the earliest valid time, and iat is when the token was issued, all in Unix seconds.
Why is my token rejected?
This tool does not validate tokens. Rejection usually comes from an expired exp, an invalid signature or a missing claim in your application.
What is Base64URL?
JWT segments use Base64URL, a URL-safe variant of Base64 without padding.
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