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ToolRuns in browser — nothing sent to server
JWT Decoder
Paste any JWT token to instantly decode its header, payload, and check expiry status.
How it works
A JWT (JSON Web Token) is a compact, URL-safe way to represent claims between two parties. It has three parts separated by dots:
header.payload.signature
The header contains the token type and signing algorithm. The payload contains the claims — who the token belongs to, when it expires, and any custom data. The signature is used to verify the token hasn't been tampered with (requires the secret key — not shown here).
This tool decodes entirely in your browser using the Web API. Your token is never sent to any server.