Does this verify the JWT signature?

No. This tool decodes the header and payload only. Signature verification requires your secret key and would need to be done server-side.

Why is it important to use a browser-based JWT decoder?

JWTs often contain sensitive data like user IDs, roles, and permissions. Pasting them into a tool that sends data to a server exposes that data. This tool processes everything locally.

What does 'signature present' mean?

It means the JWT has three parts (header.payload.signature), which is a standard signed JWT. A JWT with only two parts (no signature) is unsecured.

Can I decode expired JWTs?

Yes. The decoder works on any valid JWT structure regardless of expiry. The tool will show the expiry status clearly.

Free JWT Decoder Online

Decode JWT tokens and inspect header and payload instantly in your browser. Your tokens never leave your device.

How to use

1
Paste your JWT
Paste the full JWT token (three dot-separated parts) into the input field.
2
Inspect the decoded output
The header and payload are shown as formatted JSON. The expiry time is shown in a human-readable format.
3
Check the signature status
The tool shows whether a signature is present. Note: signature verification requires your secret and is not performed here.

Why use this tool?

Decodes entirely in your browser - your token never leaves your device
This is critical for JWTs: pasting tokens into online tools that use servers is a security risk
Shows expiry time (exp claim) as a human-readable date with expired/valid status
Formats header and payload as prettified JSON for easy reading

Frequently asked questions

Does this verify the JWT signature?: No. This tool decodes the header and payload only. Signature verification requires your secret key and would need to be done server-side.
Why is it important to use a browser-based JWT decoder?: JWTs often contain sensitive data like user IDs, roles, and permissions. Pasting them into a tool that sends data to a server exposes that data. This tool processes everything locally.
What does 'signature present' mean?: It means the JWT has three parts (header.payload.signature), which is a standard signed JWT. A JWT with only two parts (no signature) is unsecured.
Can I decode expired JWTs?: Yes. The decoder works on any valid JWT structure regardless of expiry. The tool will show the expiry status clearly.

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