Local · Private

JWT Decoder

Decode a JSON Web Token into readable header and payload, parsed on your device, with human-readable claim dates and expiry status. The signature is never sent anywhere.

Paste a JWT

Files never leave your browser. Decoding happens entirely on your device, the secret/signature is never required or transmitted.

Decoded

Header (red)

Payload (green)

Registered claims

Standard time claims interpreted as human dates (your local timezone and UTC).

Signature

NOT verified. This tool only decodes the token, it does not check the signature, because that needs the issuer's secret or public key. Do not trust a decoded token's contents as authentic without verifying the signature on a trusted server.

About JWT Decoder

JWT Decoder is a free, private browser tool that splits a JSON Web Token into its three parts and shows you the header and payload as readable JSON. It runs entirely in your browser: no upload, no server, no account. Time claims like iat, nbf, and exp are converted to human-readable local and UTC dates, and you get an instant valid, expired, or not-yet-active status chip. The signature segment is displayed as-is but never verified, because that requires the issuer secret. Like every tool by Digital Heroes, it is 100% free with no limits.

What you can do

Decode any JWT instantly by pasting it into the editor, with no setup required.

Read header and payload as formatted, indented JSON side by side.

See time claims (iat, nbf, exp) as human dates in your local timezone and UTC.

Check expiry status at a glance: valid, expired, or not yet active, with a relative countdown.

Copy the header or payload JSON with one click for use in code or docs.

Load a sample token to explore the format and registered claims with no real data.

How to use JWT Decoder

Open JWT Decoder in your browser. No signup or install needed.

Paste your JWT into the input box, or click Load sample to try a demo token.

The header and payload appear instantly as formatted JSON. Check the expiry chip at the top of the result for status.

Scroll down to the Registered claims table to read time claims as dates and see relative countdowns.

Click Copy next to Header or Payload to copy that JSON to your clipboard.

Frequently asked questions

Is JWT Decoder free?

Yes, JWT Decoder is completely free for everyone. No sign-up, no account and no usage limits.

Is it private? Are my files uploaded anywhere?

No. JWT Decoder runs entirely in your browser on your own device, so your data never leaves your computer and nothing is uploaded to a server.

Does it work offline?

Yes. This tool is a Progressive Web App, once the page has loaded it keeps working offline, and you can install it as an app from your browser.

Do I need to install anything or create an account?

No. Just open the page and start using it. Installing it as an app is optional and only adds offline convenience.

What does JWT Decoder do?

It splits a JSON Web Token into its header and payload and shows both as readable, formatted JSON. It also converts time claims (iat, nbf, exp) to human dates, shows an expiry status chip, and displays the raw signature segment for reference. Everything happens in your browser with no data sent anywhere.