JWT Decoder
Paste a JSON Web Token and read its header and payload. Decoded locally in your browser — your token never leaves your device.
How it works
- 1
Paste your JWT
Three parts separated by dots.
- 2
Read the header
Algorithm and token type.
- 3
Read the payload
Claims such as sub, iat and exp.
Related tools
Other tools people use right after this one.
Built to get out of your way
487
Tools available
6
Languages
0
Watermarks added
2h
Until your files are erased
100%
Free to start
∞
Devices supported
Frequently asked questions
No, it only decodes. Verifying requires the secret or public key.
What is inside a JWT
A JSON Web Token has three Base64URL-encoded parts: a header describing the algorithm, a payload carrying claims (like the user id or the expiry time), and a signature. Anyone can read the header and payload — they are encoded, not encrypted.
This tool decodes the first two parts. It does not verify the signature, so it cannot tell you whether the token is authentic. Never paste production secrets into tools you do not trust; here everything stays in your browser.