JWT Decoder
Paste a JSON Web Token to see its header, claims and expiry in plain English. Everything runs in your browser. Nothing you paste is uploaded or stored.
Quick answer
A JWT is three Base64URL parts — header, payload, signature — separated by dots. Paste one to read its claims and expiry time. Decoding does not verify the signature, and the token never leaves your browser. Expiry times are Unix timestamps; convert them with the timestamp converter.
- Free
- No sign-up
- Developer
- Updated October 2026
About the JWT Decoder
A JWT has three Base64URL-encoded parts separated by dots: a header (the algorithm), a payload (the claims) and a signature. The first two are just encoded JSON, so they can be read without any key.
Timestamps such as exp (expiry), iat (issued at) and nbf (not before) are Unix seconds. The decoder converts them to dates and flags expired tokens — the most common reason an API returns 401.
Decoding is not verification. To trust a token’s contents your server must check the signature with the correct secret or public key.
How to use it
- Paste the token — with or without “Bearer ”.
- Read the header and payload.
- Check the status bar for expiry.
- Copy either section as formatted JSON.
Frequently asked questions
Is it safe to paste a production token here?
Decoding happens in your browser and nothing is sent anywhere. Still, a valid token works like a password until it expires — treat it carefully.
Can this tool verify the signature?
No. Verification needs the signing secret or public key and should happen on your server.
What do sub, aud and iss mean?
sub is the subject (usually the user ID), aud the intended audience (which API should accept it), and iss the issuer (who created it).
Results are estimates for planning — check critical figures with a professional or the official source.
Popular tools
Image Converter
Convert any image to JPG, PNG or WebP, with quality and size controls.
Image
JPG to PNG Converter
Turn JPG files into PNG right in your browser — drag in one image or thirty.
Image
PNG to JPG Converter
Turn PNG files into JPG right in your browser — drag in one image or thirty.
Image
WebP to JPG Converter
Turn WebP files into JPG right in your browser — drag in one image or thirty.
Image