JWT Decoder

Decode JSON Web Tokens — view header, payload and signature. No verification, no server.

Why Use DiffMergy’s JWT Decoder?

DiffMergy’s JWT Decoder lets you inspect and debug JSON Web Tokens without sending them to a remote server. Simply paste any JWT to instantly decode its header, payload, and signature components with formatted JSON output.

An essential tool for API development and OAuth debugging. Since decoding happens entirely in your browser, you can inspect production tokens with complete confidence that your secrets stay local.

100% Private — No Server Upload

All processing happens entirely in your browser using Web Workers and modern browser APIs. Your sensitive source code, credentials, and files never leave your device — no servers, no databases, no tracking, no sign-up required.

Fast & Reliable

Built with vanilla TypeScript and a lightweight custom engine, DiffMergy delivers sub-millisecond processing with zero network latency. The entire toolkit works on any modern browser across all operating systems, with no installation or setup needed.

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