Developer · JWT

JWT Decoder

Decode a JSON Web Token header and payload in your browser and inspect its expiration time.

Use this toolON-DEVICE

Decodes content only. The signature is not verified.

GUIDE · 2026-07-23

How to use the JWT Decoder

Quickly inspect JWT claims while keeping the distinction between decoding and signature verification clear. The result follows “JWT = Base64URL(header) . Base64URL(payload) . signature” and is designed for situations such as inspect access-token claims during development. Inputs are handled immediately in your browser with no account required.

How it works

JWT = Base64URL(header) . Base64URL(payload) . signature

Most processing stays in your browser instead of sending inputs to our server. Verify important financial or contractual decisions against an authoritative source.

Useful examples

  • Inspect access-token claims during development
  • Read exp and iat timestamps as dates
  • Find which token segment has invalid formatting

Frequently asked questions

Does this verify the signature?

No. It only decodes the contents and does not verify the signature with a secret or public key.

How is expiration determined?

The exp claim is treated as Unix seconds and compared with the current time.

Should I paste a production token?

Processing stays on-device, but tokens may be sensitive. Avoid real production tokens on shared devices.