JWT Debugger decodes JSON Web Tokens into their three components — header, payload, and signature — and displays all claims in a structured, readable format without sending your token to any server. JWTs are the dominant authentication mechanism in modern web apps and APIs: they encode user identity, roles, expiry times, and custom claims in a compact signed format used by OAuth 2.0, OpenID Connect, and custom auth systems. The tool highlights expiry claims (exp, iat, nbf) as human-readable timestamps, immediately showing whether a token is expired or when it will expire — critical for debugging 401 Unauthorized errors. Designed for backend engineers debugging auth flows, frontend developers inspecting tokens from SSO providers, and security teams auditing what data is embedded in tokens.

Simply input your data into the fields above. Our JWT Debugger will process your information instantly. You can then copy the results or export them depending on the specific tool features like Real-time Decoding or Hover-to-Date Timestamps.

Yes, the JWT Debugger on ToolsHubKit is 100% free to use. we don't require any signup, subscriptions, or hidden fees. It is part of our suite of professional developer utilities designed for the community.

Your privacy is our primary concern. All processing for the JWT Debugger occurs locally within your browser. No data is ever uploaded to our servers or stored in any cloud environment. You can even use this tool offline.