JWT Decoder
Paste a JSON Web Token to decode and inspect its header, payload, and signature. No data is sent to any server.
How to Use
How to use the JWT Decoder
Paste your JWT
Paste a JSON Web Token into the input area. It should have three parts separated by dots.
Click Decode JWT
Hit the button or press Cmd+Enter. The tool instantly parses the header, payload, and signature.
Inspect the claims
View all claims in a formatted table. Timestamps (exp, iat, nbf) are automatically converted to human-readable dates.
Check expiration
A colored badge shows whether the token is still valid or expired, with the exact time remaining.
Features
Why use our JWT Decoder?
Color-Coded Preview
Header, payload, and signature are highlighted in distinct colors so you can see each part at a glance.
Expiration Detection
Instantly shows whether the token is expired or valid, with a countdown to expiration.
Claims Table
Every claim is listed in a clean table with descriptions for standard claims and timestamp conversion.
100% Client-Side
Your token never leaves your browser. No data is sent to any server — completely private.
Algorithm Display
Shows the signing algorithm (HS256, RS256, etc.) and token type from the JWT header.
Sample Token Included
Click 'Load sample' to see how the decoder works before pasting your own token.
FAQ
JWT Decoder — Common Questions
Yes, 100% free with no sign-up or account required. Use it as often as you need.
No — signature verification requires the secret key or public key, which should never be shared in a browser tool. This tool decodes and displays the header, payload, and signature for inspection only.
Yes. Nothing leaves your browser. The entire decoding process runs client-side in JavaScript. No data is sent to any server.
It recognizes all standard JWT claims: sub (subject), iss (issuer), aud (audience), exp (expiration), iat (issued at), nbf (not before), jti (JWT ID), plus custom claims like name, email, and role.
After decoding, the tool checks the 'exp' claim and shows a badge: green if the token is still valid (with time remaining), or red if it has expired.
The decoder works with any JWT regardless of the signing algorithm (HS256, RS256, ES256, etc.) since it only decodes — it doesn't verify signatures.
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