JWT Lens

Decode & verify JWTs offline

Free

Inspect any JSON Web Token in a tap: color-coded header & payload, human-readable expiry, and local signature verification. 100% on-device — no network, no tracking. JWT Lens is a fast, private JSON Web Token decoder and verifier for developers — a Safari extension that works entirely on your device. Tap the toolbar icon, paste a token (or grab the text you've selected on the page), and instantly see: • Pretty-printed, color-coded Header and Payload • Human-readable timestamps — exp, iat and nbf shown in your local time with relative phrasing ("expires in 59 minutes") • An at-a-glance expiry badge: valid, expired, or not yet valid • Plain-English descriptions of standard claims (iss, sub, aud, and more) Need to check a signature? JWT Lens verifies HS256/384/512, RS256/384/512, PS256/384/512 and ES256/384/512 using a secret or PEM public key you provide — all computed locally with the system's WebCrypto, never sent anywhere. Privacy by design: • No network requests — ever • No analytics, no tracking, no accounts • Nothing is stored: tokens and keys live only in the popup while you use it Whether you're debugging OAuth / OIDC flows, inspecting a bearer token, or learning how JWTs work, JWT Lens keeps it quick, clear, and completely on-device. Universal app: works in Safari on macOS, iOS and iPadOS.

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The developer, Masaya Kontani, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

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    Information

    Seller
    • Masaya Kontani
    Size
    • 715.8 KB
    Category
    • Developer Tools
    Compatibility
    Requires iOS 16.4 or later.
    • iPhone
      Requires iOS 16.4 or later.
    • iPad
      Requires iPadOS 16.4 or later.
    • Mac
      Requires macOS 13.3 or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • English
    Age Rating
    4+
    Copyright
    • © 2026 Masaya Kontani
  • Developer Website
  • Privacy Policy

    • More by Masaya Kontani

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