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JWT Decoder
Paste a JSON Web Token to see its header and claims, with exp, iat and nbf turned into dates and a clear expired or valid label. Add the secret or public key to check the signature.
Loading JWT Decoder…
Runs on your device. Nothing you paste is uploaded.
How to use the JWT Decoder
- Paste the token (the three dot-separated parts). A “Bearer ” prefix is removed for you.
- Read the decoded header and payload. Time claims are shown as dates in your time zone.
- To verify the signature, paste the HMAC secret or the PEM public key the issuer publishes.
Private by design
Plenty of online tools send what you paste to their server, which is a real risk with API keys, tokens and customer data. JWT Decoder runs entirely in your browser: nothing is uploaded, logged or stored, and it keeps working with your network switched off. It’s free, with no account and no limits.
Questions
Is it safe to paste a real token here?
The token is decoded and verified in your browser and never sent anywhere. Many online decoders do send tokens to a server, and a live token is as good as a password until it expires.
Which signing algorithms can it verify?
HS256, HS384 and HS512 with a shared secret; RS256, RS384, RS512, PS256, PS384 and PS512 with an RSA public key; and ES256, ES384 and ES512 with an elliptic-curve public key. Keys go in as PEM (-----BEGIN PUBLIC KEY-----) or as a JWK.
Does decoding a JWT mean it’s valid?
No. Anyone can read a JWT’s contents, because they’re only Base64-encoded. A token should be trusted only after its signature checks out and its exp and nbf times allow it.
Is anything I paste sent to a server?
No. Every tool runs in your browser, so tokens, keys, customer data and code stay on your device. Once the page has loaded, the tools work offline too.
Do I need an account?
No. Every developer tool is free to use without signing in, with no limits.
Related tools
- Base64 Encode and Decode Convert text or files to Base64 and back, with URL-safe output.
- Unix Timestamp Converter Epoch time to a date and back, in any time zone.
- JSON Formatter Pretty-print, minify and validate JSON, with the line of any error.
- Hash Generator MD5, SHA-1, SHA-256 and SHA-512 hashes of text or files.
Part of Developer Tools
16 free developer tools that run in your browser: format JSON, decode JWTs, test regex, compare text and encode Base64 without sending anything to a server.
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