JWT Decoder

A FREE, offline, privacy-first app to decode and inspect JWT tokens instantly.

Usage is very simple:

## Paste a token and see:

- The decoded Header, Payload, and Signature, each color-coded for instant readability

- Syntax-highlighted JSON with clearly labeled keys and values

- Smart claim chips for standard fields — issuer, subject, audience, scopes, roles, and more

- Expiry status at a glance — expired tokens are flagged immediately, with a human-readable countdown ("Expires in 3h 22m" or "Expired 2d 14h ago")

- Issued-at and not-before timestamps converted to local date and time

## Designed for daily developer use:

- Auto-decode on paste — the moment you paste a token, the result appears

- One-tap clipboard paste

- Built-in sample tokens to explore the UI without needing a real token

- History panel that stores your last 30 decoded tokens for quick reference

- Tap any history entry to reload and re-inspect it

## Clean, distraction-free interface:

- Light and dark mode, with automatic detection based on system preference

- Collapsible sections for Header, Payload, and Signature — focus on what matters

- Monospace rendering for all token data

- Works fully offline — no network access needed, no data ever leaves your device

## Privacy first:

JWT Decoder decodes tokens entirely on-device using standard Base64 parsing. Your tokens are never sent to any server. History is stored only in local app storage and can be cleared at any time.

## Perfect for:

- Debugging OAuth2 and OpenID Connect flows

- Reviewing access tokens and ID tokens

- Inspecting claims during API development

- Learning how JWTs are structured

Simple, fast, private, and built for developers.