JWT Decoder
Paste any JSON Web Token and inspect its header, payload, and signature. Timestamp claims (iat, exp, nbf) are converted to human-readable dates. Runs 100% in your browser — nothing leaves your device.
// Decoded token will appear here…
About JWT Decoder Tool
This free online JWT decoder splits any JSON Web Token into its three parts — header, payload, and signature — and parses the Base64URL-encoded JSON client-side. Timestamp claims such as iat, exp, and nbf are converted to ISO-8601 for easy inspection. Perfect for debugging OAuth2, OpenID Connect, and custom auth flows.
What is a JWT?
A JSON Web Token is a compact, URL-safe credential consisting of three Base64URL-encoded parts: a header describing the signing algorithm, a payload carrying claims, and a signature protecting the integrity of the first two parts. JWTs are the backbone of modern stateless authentication and API authorization.
Key Benefits
- Fully private: Tokens are decoded locally — safe for production credentials
- Timestamp formatting: iat, exp, and nbf are shown as human-readable ISO dates
- Readable layout: Clear separation between header, payload, and signature
- Copy payload: One-click copy of the full JSON payload
- No installation: Works in any modern browser without extensions
Privacy and Security
Decoding happens entirely in your browser. Your token — potentially containing user IDs, email addresses, scopes, or custom claims — is never sent to a server. Note that this tool does not verify the signature; decoded content should be considered untrusted until verified by a backend using the correct signing key.
Instant decoding
Base64URL and JSON parsing happen in milliseconds, right in your browser.
Fully private
Tokens are decoded locally. Nothing is sent to any server — safe for production credentials.
Claim formatting
Timestamps like iat, exp, and nbf are converted to human-readable ISO dates.