JWT Decoder & Token Inspector
Decode JSON Web Tokens (JWT) client-side. Inspect header claims, payload data, expiration times, and token signatures.
Batch workspace
Format multiple files locally in one run.
Security Notice: Real Token Credentials
Pasted JSON Web Tokens may contain live authentication credentials, signatures, and sensitive claims. Decoding is performed 100% locally in your browser. Sharing links is disabled for this tool.
How to use the JWT Decoder
Paste code or file
Paste your raw TEXT text or upload directly.
Configure options
Choose indentation, dialect, or formatting preferences.
Format & export
Click format, then copy, download, or inspect in tree view.
What is a JWT Decoder?
Decode JSON Web Tokens (JWT) client-side. Inspect header claims, payload data, expiration times, and token signatures. This tool re-indents and organizes code according to standard style conventions while checking for syntax validity. Everything executes 100% inside your browser, guaranteeing zero latency and complete privacy for API keys, user tokens, and confidential database schemas.
JWT inspection is a privacy-sensitive workflow. This decoder runs locally, warns about live credentials, and disables share links so tokens are never uploaded.
Common errors and fixes
Invalid token: expected 3 parts
A JWT must have header.payload.signature separated by dots. Paste the full token.
Failed to decode Base64URL segment
The token is truncated or corrupted. Copy it again without line breaks or spaces.
Payload is not valid JSON
The middle segment must decode to JSON claims. This tool does not verify signatures.
Token appears expired
The exp claim is in the past. Decoding still works; treat the session as expired.
Options Explained
| Option | Description |
|---|---|
| Parse epoch timestamps (exp, iat, nbf) | Translates numeric Unix epoch timestamps into human-readable UTC date and expiration status strings. |
Frequently Asked Questions
Is it safe to paste real JWT authentication tokens here?
Yes. All decoding occurs 100% inside your browser using client-side JavaScript. Tokens are never transmitted to any external server.
Does this tool verify the signature of the JWT?
No. Verifying a cryptographic signature requires a secret or public key. This tool inspects and decodes the claims structure.
How does the tool check if my JWT is expired?
It reads the standard 'exp' (expiration) claim in the JWT payload and compares it against the current client timestamp.
What is the three-part structure of a JWT?
A standard JWT consists of three Base64URL-encoded segments separated by dots: Header (algorithm & token type), Payload (claims data), and Signature.
Why should I avoid sending JWTs to random web tools?
JWTs often contain sensitive user IDs, roles, and session tokens. You should only use verified zero-server tools like Code Beautifier.