What is the JWT Inspector?
The JWT Inspector is a browser-based tool that decodes and inspects JSON Web Tokens (JWTs). Paste any JWT and instantly see the decoded header, payload, and standard claims. You can also verify HMAC-based signatures using a shared secret — all without sending your token to any server.
Why Use a JWT Inspector?
JWTs are compact but opaque — their content is base64-encoded and not immediately readable. A JWT inspector helps you:
- Debug Authentication Issues: Quickly inspect token claims like expiry, issuer, and audience to diagnose auth failures.
- Verify Token Signatures: Confirm that a token was signed with the correct HMAC secret before trusting its contents.
- Understand Token Structure: Learn how JWTs are constructed by exploring the header algorithm and payload claims.
- Stay Secure: Decoding and verification happen entirely in your browser; your tokens and secrets never leave your device.
Features of Our JWT Inspector Tool
Our JWT Inspector provides everything you need to understand and validate a JWT:
- Header and Payload Decoding: Instantly decode the base64url-encoded header and payload into formatted JSON.
- Standard Claims Display: See issued-at, expiry, not-before, issuer, and audience claims in a human-readable format.
- HMAC Signature Verification: Enter a shared secret and select HS256, HS384, or HS512 to verify the token signature.
- Expiry Status: The tool highlights whether a token is still valid or has already expired.
- Local Processing: All decoding and verification runs client-side; no network requests are made with your token data.
How to Use the JWT Inspector Tool
- Paste Your JWT: Enter the full JWT token in the input field. The token must be in the standard three-part format separated by dots.
- Review the Decoded Data: Examine the decoded header and payload, along with standard claim details such as expiry and issuer.
- Verify the Signature: Enter the shared secret and choose the HMAC algorithm (HS256, HS384, or HS512) to check signature validity.
- Check Security Details: Confirm that audience and issuer claims match expectations, and verify that expiry and not-before times are correct.
Try Our JWT Inspector Tool
Need to inspect or verify a JWT quickly? Use our JWT Inspector to decode any token and validate its signature in seconds — with complete privacy, as all processing stays in your browser.