JWT Decoder is a 100% free, browser-based utility that enables you to decode json web tokens: header, payload and expiry. Unlike traditional cloud converters, all processing executes locally on your device with zero server uploads, delivering immediate results and ironclad data privacy.
About the JWT Decoder
A JSON Web Token (JWT) has three Base64URL-encoded parts separated by dots: a header describing the algorithm, a payload of claims such as the user ID and expiry time, and a signature. This decoder shows the header and payload as formatted JSON and converts timestamp claims (exp, iat, nbf) into readable dates, telling you whether the token has expired.
Tokens are decoded entirely in your browser, which matters because JWTs are often live credentials. Note that decoding does not verify the signature; verification requires the secret or public key and should happen on your server.
How to use the JWT Decoder
- Paste a JWT (with or without the "Bearer " prefix).
- Read the decoded header, payload and the token status.
- Copy the header or payload JSON if you need it.
Features
- Header & payload as JSON
- exp / iat / nbf as dates
- Expired / valid indicator
- Never leaves your browser
Why Choose In-Browser JWT Decoder vs Cloud Converters?
| Feature | Toolora (In-Browser) | Traditional Cloud Tools |
|---|---|---|
| Data Privacy | 100% Private (Files stay on device) | Uploaded to remote servers |
| File Size Limits | Unlimited (Limited only by your RAM) | Restricted (e.g. 10MB–50MB caps) |
| Processing Speed | Instant (Zero upload/download delay) | Slow upload & queue waiting |
| Ads & Popups | Clean, distraction-free | Heavy banner & interstitial ads |
Frequently asked questions
Does this tool verify the JWT signature?
No. It only decodes the token. Anyone can read a JWT's contents; the signature only proves the token was not modified, and checking it requires the signing key.
Is it safe to paste a production token?
The token is decoded locally and never sent anywhere. Still, treat tokens like passwords and avoid sharing them, as a valid token can be used to access the account until it expires.
What do exp, iat and nbf mean?
exp is the expiry time, iat is when the token was issued, and nbf ("not before") is when it becomes valid. They are Unix timestamps in seconds.