JWT Decoder
Decode a JWT token and view its Header and Payload instantly
About JWT Decoder
Fastols' JWT Decoder decodes any JSON Web Token and shows you its Header and Payload content in a clear, formatted layout, so you can understand the encoded data and verify its structure.
The tool only reads the token — it does not verify the signature and does not need the secret key, so it's meant purely for decoding and reading the content. Everything runs inside your browser — no data is uploaded to any server. Still, be careful when pasting a real token from a production system since tokens can be sensitive.
How to use JWT Decoder
- 1Paste the full JWT token into the box
- 2The Header and Payload data appears automatically, formatted
- 3Click "Copy Result" to copy the decoded data
Frequently Asked Questions
Does the tool verify the token's signature?
No, the tool only decodes the Header and Payload for reading — signature verification requires the secret key.
Is it safe to paste a real token?
Processing happens entirely inside your browser and no data is uploaded to any server, but it's always best to be careful with sensitive access tokens from real production systems.
Is the tool completely free?
Yes, 100% free with no usage limit.