JWT Decoder — Inspect JWT Tokens Free

Decode any JWT token and inspect the header, payload claims, signature, and expiry. No token data is stored.

How to Use JWT Decoder

Enter InputType or paste your input data into the tool interface

ProcessClick the action button to run the tool

Use OutputCopy or download the result for your project

JWT Decoder — Free Developer Utility

JWT Decoder — decode and inspect JSON Web Tokens instantly without any backend request. JWT (JSON Web Token) is the authentication standard used by virtually every modern web API and single-page application. A JWT consists of three base64url-encoded parts separated by dots: the header specifying the algorithm, the payload containing claims like user ID and expiry, and the signature for verification. When debugging authentication issues, you need to decode jwt tokens to see what claims are present, when the token expires, and which algorithm was used. Our tool decodes all three parts and clearly displays when the token expires so you can immediately spot expiry-related auth failures.

Keywords and Search Terms

Developers searching for this tool use terms like: jwt decoder, decode jwt, jwt token, jwt payload, json web token. Tooliby provides this utility free with no signup, no watermarks, and no data logging.

Privacy — Your Data is Never Stored

Every input you paste into Tooliby developer tools is processed in memory and immediately discarded. We do not log inputs, store results, or analyze your data. Your code, tokens, API keys, and sensitive strings stay completely private.

Frequently Asked Questions

Our tool decodes the jwt token entirely in your browser using JavaScript — no token data is sent to our servers. For production tokens containing sensitive user data, use browser dev tools or a local JWT library.

The jwt payload contains the claims — structured data about the subject. Standard claims include sub (subject/user ID), exp (expiry timestamp), iat (issued at), and iss (issuer). Applications add custom claims for roles, permissions, and user data.

JWT signature verification requires the secret key. Our tool decodes the header and payload but does not verify the signature since we do not have your secret. To verify, use your backend JWT library.

Decode means reading the header and payload from the base64url-encoded parts — anyone can do this. Verify means checking the signature using the secret key to confirm the token was not tampered with.

The exp claim in the jwt payload is a Unix timestamp of when the token expires. If the current time is past that timestamp, the token is expired and your API will reject requests with it. Generate a new token to continue.