JWT Decoder
Paste a JSON Web Token to inspect its header and payload, check expiry with readable timestamps, and verify structure — entirely on your device.
Runs 100% in your browser — nothing is ever uploaded.
What is JWT Decoder?
Decode JWT tokens online: view header, payload and expiry with human-readable timestamps. 100% client-side — tokens never leave your browser. Paste your content, get an instant result, and copy or download the output with a single click. Free and unlimited, with no watermarks and no registration — all processing happens right in your browser, so nothing is ever sent to a server.
How to use JWT Decoder
- Open JWT Decoder — it loads instantly and needs no sign-up.
- Paste or type your input into the editor (or press Sample to try an example).
- Adjust the available options if needed and press the action button.
- Copy the result with one click or download it as a file.
Frequently asked questions
Is JWT Decoder really free?
Yes — JWT Decoder is 100% free with no limits, no watermarks and no registration. You can use it as often as you like, on as many files or inputs as you need.
Is my data safe when I use JWT Decoder?
Absolutely. JWT Decoder runs entirely in your browser using JavaScript — your input is processed on your own device and is never uploaded to any server.
Does JWT Decoder work on mobile devices?
Yes. JWT Decoder works in any modern browser on desktop, tablet and mobile (Chrome, Firefox, Safari, Edge) — there is no app to install.
Is it safe to generate passwords in a browser?
Yes — we use the Web Crypto API (crypto.getRandomValues), the same cryptographically secure randomness source used by password managers. Generation happens on your device and nothing is transmitted or stored.
Do you see the JWT tokens I decode?
No. Decoding is pure client-side Base64 parsing — the token never leaves your browser. Still, avoid pasting production secrets anywhere as a general habit.
Are the UUIDs really unique?
UUID v4 has 122 random bits — the collision probability is so small it is negligible for any real-world system. We use the native crypto.randomUUID() implementation.