JWT Decoder: a jwt decoder tool that never sees your data

Most online jwt decoder tools quietly send what you paste to a server. That's
fine until it isn't — config blobs, tokens, and API responses are exactly the
kind of thing you don't want leaving your machine.

So JWT Decoder takes the opposite approach: it's a single, self-contained page
that runs entirely in your browser.

How it works

JWT Decoder is 100% in your browser — nothing is uploaded to a server. There's no backend and no API call for the core
function. You can verify it yourself:

1. Open the page.
2. Open DevTools → Network.
3. Use the tool.
4. Watch the Network tab stay empty.

The whole thing is one HTML file — View Source shows the JS that runs
everything. It can't leak your data because it never receives it.

What it does

Decode JWT header, payload, and claims — expiry countdown, claim notes, 100% browser-side.

• Fast, single-purpose, no signup
• Works offline (save the page)
• No tracking beyond a privacy-friendly analytics beacon

Why browser-side matters

The convenient online dev tools we paste into are an under-appreciated
supply-chain risk. The fix isn't a warning banner — it's architecture: if the
tool runs on your machine, there's no breach to have. That's the principle
behind the whole platotools.com set (JSON, JWT,
hashing, encoding, regex, diff) — all client-side, all single-purpose.

Try it: https://jwt.platotools.com/

If you hit an edge case, I'd genuinely like the bug report.