JWT Decoder
Decode and inspect the header and payload of any JWT token. Runs entirely in your browser.
Header
{
"alg": "HS256",
"typ": "JWT"
}Payload
{
"sub": "123",
"name": "John Doe",
"iat": 1516239022
}Signature
dummy
About the JWT Decoder
Paste a JSON Web Token and instantly view its header and payload. Useful for debugging auth flows without exposing your secret to a third-party service.
How to use the JWT Decoder
- 1Paste the JWT.
- 2Read the decoded header and payload panels.
- 3Copy any field you need.
Why people use it
- Debug an OAuth or Supabase session token.
- Inspect an API's issued claims.
- Verify the `exp` claim on a suspect token.
Frequently asked questions
Does it verify the signature?
No — verification requires the signing key. This tool decodes only, so it stays fully client-side and safe for sensitive tokens.
Is my token sent anywhere?
No — decoding happens entirely in your browser.
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