JWT Decoder - Decode and Inspect JSON Web Tokens

Decode JSON Web Tokens (JWTs) instantly with our free online JWT Decoder. Paste any JWT to inspect its header, payload claims, and expiration status without needing a secret key. A must-have tool for developers working with authentication, APIs, and token-based security.

Features

• Instant token decoding that splits and decodes the header, payload, and signature sections
• Claims inspection displaying all standard and custom claims in a readable, formatted view
• Expiration checking that highlights whether the token is still valid or has expired based on the exp claim
• Issued-at and not-before timestamps converted to human-readable dates for easy verification
• Color-coded token segments visually separating the header (red), payload (purple), and signature (blue)
• Raw and decoded views letting you switch between the Base64URL-encoded string and the parsed JSON
• No secret key required since decoding a JWT only requires Base64 decoding, not signature verification

How to Use

1. Paste your JWT string into the input field at the top of the page.
2. The tool instantly splits the token and decodes each section.
3. Review the header to see the signing algorithm and token type.
4. Inspect the payload claims, including subject, issuer, expiration, and any custom data.
5. Check the expiration status indicator to see whether the token is currently valid or expired.

Use Cases

• API debugging: Inspect the contents of access tokens returned by OAuth providers to verify claims and scopes are correct.
• Authentication troubleshooting: Check whether a token has expired or contains unexpected claim values when users report login issues.
• Security auditing: Review tokens to ensure sensitive data is not being stored in the payload and that appropriate expiration times are set.
• Learning and education: Understand the structure of JWTs by decoding example tokens and examining each part.

FAQ

Is it safe to paste my JWT into this tool?

Yes. All decoding happens entirely in your browser. Your token is never sent to any server. That said, treat JWTs like passwords and avoid sharing them in public channels regardless of the tool you use.

Can this tool verify the token's signature?

This tool focuses on decoding and inspecting the token contents. Signature verification requires the secret key or public key used to sign the token, which is intentionally not part of this tool's scope to keep your keys secure.

What are the most important claims to check?

The exp (expiration time), iat (issued at), and sub (subject) claims are the most commonly reviewed. The iss (issuer) and aud (audience) claims are also important for verifying that the token was issued by the expected authority and intended for your application.