Is it safe to use the JWT Decoder online?

Yes — and ours is safer than most. Many free online tools quietly upload your files to their servers to do the work. We don't. Everything happens inside your browser on your own device, so your files never reach the internet. There's no upload step, no server copy, and no way for us (or anyone else) to see what you're working on.

Are my files uploaded to a server?

No. There's no server-side processing here. The whole tool is a tiny app that runs in your browser — we don't even have a server that could receive your files. You can confirm this by opening your browser's network tab while you use the tool: nothing leaves your device.

Do I need to sign up or pay?

No. There's no account, no email collection, no credit card. The tool is free to use as much as you want, on as many files as you want. We're supported by a few unobtrusive ads on the page — not by your data.

Does this verify the signature?

No. Signature verification requires the issuer's public key, which the tool doesn't have. We only decode and display the parts.

No. Decoding happens entirely in your browser. We have no server.

Standard JWT claims: exp = expiry timestamp, iat = issued-at, nbf = not-before. All in Unix seconds.

JWT Decoder

Decode any JSON Web Token (JWT) into its three parts: header, payload, signature. The header and payload are pretty-printed JSON; the signature is shown as base64. Useful for inspecting OAuth tokens, debugging auth flows, and verifying claims.

Features

Decodes header, payload, signature
Pretty-prints decoded JSON
Highlights expiry (exp), issued-at (iat), not-before (nbf) with human-readable times
Detects malformed JWTs and shows a helpful error
100% client-side — your token never leaves your browser

How to jwt decoder

Paste your JWT — Drop in a token (eyJ...). Three dot-separated parts.
Read the parts — Header shows the algorithm. Payload shows the claims. Signature is base64.
Verify expiry — Check the iat/exp times shown next to the payload.

Frequently asked questions

Is it safe to use the JWT Decoder online?: Yes — and ours is safer than most. Many free online tools quietly upload your files to their servers to do the work. We don't. Everything happens inside your browser on your own device, so your files never reach the internet. There's no upload step, no server copy, and no way for us (or anyone else) to see what you're working on.
Are my files uploaded to a server?: No. There's no server-side processing here. The whole tool is a tiny app that runs in your browser — we don't even have a server that could receive your files. You can confirm this by opening your browser's network tab while you use the tool: nothing leaves your device.
Do I need to sign up or pay?: No. There's no account, no email collection, no credit card. The tool is free to use as much as you want, on as many files as you want. We're supported by a few unobtrusive ads on the page — not by your data.
Does this verify the signature?: No. Signature verification requires the issuer's public key, which the tool doesn't have. We only decode and display the parts.
Is my token logged?: No. Decoding happens entirely in your browser. We have no server.
What's exp/iat/nbf?: Standard JWT claims: exp = expiry timestamp, iat = issued-at, nbf = not-before. All in Unix seconds.