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JWT Decoder & Token Parser

Decode JSON Web Tokens (JWT) locally. View token metadata, claims, issue dates, and validation status instantly.

Signature Warning

Our tool decodes JWT payloads locally in your browser. Be aware that client-side decoders do not verify the digital signature against a secret key. To confirm token authenticity, always verify it on your secure backend.

Standard JWT Claims

  • sub: Subject (typically the User ID)
  • iss: Issuer (the server that generated the token)
  • aud: Audience (intended recipient API)
  • exp: Expiration unix time stamp
  • iat: Issued At unix time stamp

Complete Guide: How to Use the JWT Decoder

Extracting claims and auditing token expiration times is a routine necessity when building federated authentication, debugging SSO pipelines, or investigating API header calls. Our free online JWT Decoder parses JSON Web Tokens in a split second, converts Unix timestamps to local timezone dates, and presents beautifully formatted JSON segments, all processed safely in your browser.

Step-by-Step Instructions

  1. Paste your encoded JSON Web Token (JWT) string into the inputs text box.
  2. The decoder automatically splits the token into its three constituents: Header, Payload, and Signature.
  3. Review the parsed JSON elements. The Header details the signing algorithm; the Payload lists the token claims and metadata.
  4. Examine the 'Token Expiry Status' panel, which automatically parses 'exp' and 'iat' claims and shows token expiration dates.
  5. Copy header or payload elements using the corresponding 'Copy' buttons.

Key Features & Benefits

  • Instant Automated Decoding: Extracts and parses JWT parts on-the-fly as you paste or type.
  • Claim Expiry Diagnostics: Converts unix epochs ('exp', 'iat', 'nbf') to readable local dates and highlights current validation status.
  • Zero Client-Server Latency: Operates entirely inside client-side JS context, keeping private Auth tokens out of remote logs.
  • Structured JSON Outputs: Prettifies headers and payload bodies with clean color schemes and fonts.

FAQs about JWT Decoder

What is a JWT (JSON Web Token)?
What are the three parts of a JWT?
Does this tool verify the signature of the JWT?
Is pasting my JWT token here secure?