JWT Inspector
Free online JWT Inspector. Decode and analyze JSON Web Tokens in detail — check expiration, view claims, see token structure. All local, no data sent anywhere.
Token Structure
Claims Breakdown
| Claim | Value | Type | Description |
|---|
How to Use JWT Inspector
Paste Your JWT
Paste a JSON Web Token into the input field. A valid JWT has three parts separated by dots: header.payload.signature.
Click Inspect
Click "Inspect JWT" to decode and analyze the token. The tool extracts the header and payload, checks the expiration, identifies the algorithm, and breaks down each claim.
Review the Analysis
The inspector shows: token structure, claim-by-claim breakdown, expiration status with a visual indicator, issue time in human-readable format, and the signing algorithm used.
Frequently Asked Questions
What does the JWT Inspector show that the JWT Decoder doesn't?
The Inspector goes beyond basic decoding. It shows: whether the token is expired (with a visual indicator), human-readable dates for iat/exp/nbf claims, the time remaining before expiration, claim-type analysis, and token structure visualization. It's designed for debugging and understanding JWTs at a glance.
How is the expiration check performed?
The tool reads the "exp" (expiration) claim from the JWT payload and compares it to your computer's current time. Green means the token is still valid, red means it's expired, and yellow means it expires within the next hour (a warning to refresh soon).
Does this tool verify JWT signatures?
No — signature verification requires the secret key or public key, which this tool doesn't ask for. The Inspector is for examining the contents and structure of JWTs. For signature verification, use a server-side JWT library with the appropriate secret or public key.
Inspecting JWTs for Debugging
When debugging authentication issues, the JWT Inspector is your first stop. Got a 401 Unauthorized? Paste the token here first — the most common causes are expired tokens, wrong audience (aud claim), or missing required claims. The expiry bar gives you an instant visual read on whether the token is still valid, and the claims breakdown helps you spot missing or unexpected claims.
Standard JWT Claims
- iss (Issuer) — Who created the token
- sub (Subject) — Who the token is about (usually a user ID)
- aud (Audience) — Who the token is intended for
- exp (Expiration) — When the token expires (Unix timestamp)
- nbf (Not Before) — When the token becomes valid
- iat (Issued At) — When the token was created