JWT Decoder
Paste a JSON Web Token to inspect its header and payload, with claim dates and expiry. Decoded locally: the token never leaves your browser and the signature is never sent anywhere.
What watches these brands watches your clients too
End the manual growth tax.
Running checks by hand eats valuable agency time. Uptimeify monitors your entire client portfolio from one place: on a fair, organization-wide quota model, on secure EU infrastructure. No per-client fees, no surprises.
Frequently asked questions about JWT Decoder
A JSON Web Token has three Base64url parts: header, payload and signature. This tool decodes the header and payload into readable JSON and surfaces the time claims (iat, nbf, exp), including whether the token is already expired. It does not, and cannot, verify the signature without the secret or public key.
Decoding happens entirely in your browser: the token is never uploaded. Still, treat tokens as secrets: anyone with a valid token can act as you until it expires. Because Uptimeify is EU-built and EU-hosted and this tool is client-side, your data stays off US infrastructure and clear of US Cloud Act exposure.
APIs you monitor are often protected by bearer tokens. Decode one here to check its expiry while setting up an authenticated check, then let Uptimeify watch the endpoint, it alerts you the moment auth breaks or the API stops returning what it should.
Ready to Catch Expired Access Before the Support Ticket?
You decode a token once something is already stuck. Uptimeify checks protected endpoints on an interval and reports the moment the response stops matching what you expect.