JWT Decoder
Paste a JWT token and instantly decode its header and payload as formatted JSON. Check token expiration status, issued-at time, and other standard claims. This tool decodes tokens client-side without verifying the signature. Perfect for debugging authentication flows and inspecting API tokens.
How to Use
- 1
Paste Your JWT
Paste the full JWT token (header.payload.signature) into the input field.
- 2
Inspect the Parts
View the decoded header and payload as formatted JSON, plus the raw signature.
- 3
Check Expiration
See if the token has expired and when it was issued based on the exp and iat claims.
Examples by Niche
Decode a Bearer token from an API response to check the user claims and expiration
Inspect an ID token from an OAuth provider to verify the issuer and audience claims
Check the exp claim to understand why a user session expired unexpectedly
Frequently Asked Questions
Is it safe to paste my JWT here?
This tool runs entirely in your browser. No data is sent to any server. However, never paste production tokens on untrusted websites.
Does this tool verify the JWT signature?
No, this tool only decodes the token to show the header and payload. Signature verification requires the secret key or public key, which should never be shared client-side.
What are the three parts of a JWT token?
A JWT consists of three Base64URL-encoded parts separated by dots: the header (specifying the algorithm and token type), the payload (containing claims like user ID, expiration, and issuer), and the signature (which verifies the token has not been tampered with).
How do I check if my JWT has expired?
Paste your JWT into the decoder and look for the "exp" (expiration) claim in the payload. The tool automatically converts this Unix timestamp to a human-readable date and shows whether the token is currently expired or still valid.
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