JWT Decoder

JSON Web Tokens (JWTs) are a compact, URL-safe way to represent claims between two parties. A JWT consists of three parts: a header, a payload, and a signature, each Base64URL-encoded and separated by dots.

This tool decodes the header and payload sections of a JWT so you can inspect the algorithm, claims, and expiration status. It does not verify signatures — that requires the signing key.

Common use cases include debugging OAuth tokens, inspecting API authentication tokens, and verifying token expiry. All decoding happens locally in your browser.