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Cookie Lens

Cookie Lens is a Chrome DevTools panel built around browser cookies. Inspect, edit, mock, and audit them in one place — without ever sending a value off your machine.

Chrome's built-in Application tab shows cookies as flat key-value strings — fine for a quick look, painful for real debugging. Cookie Lens treats cookies as structured data: it decodes JWT, JSON, Base64, and URL-encoded values so you can read what's actually inside, lets you mock cookies for testing while preserving the originals, protects critical session cookies from accidental deletion, and audits the whole site for security, privacy, expiry, and size issues.

Who is it for?​

Cookie Lens is designed for:

  • Frontend engineers debugging session management and client-side cookie behavior
  • QA engineers testing cookie-dependent features and consent flows
  • Backend engineers verifying server-set cookies and expiry configurations
  • Web platform teams auditing security, privacy, and compliance
  • Anyone debugging cookies in modern web applications

Key Features​

  • Inspect cookies for the current site with full details (domain, path, expiry, flags)
  • Search, filter, sort, pin, and protect cookies to focus on what matters
  • Detect expired, oversized, risky, or misconfigured cookies
  • Edit cookie values and attributes (domain, path, expiration, SameSite, Secure, HttpOnly)
  • Parse structured values — JSON, Base64, JWT, query strings, and more
  • Mock cookie values for testing without losing the original during the session
  • Report on security, privacy, expiry, and size issues
  • Export/Import cookies for sharing or testing across environments
  • Track which network response set or updated each cookie (optional)

Privacy-First Design​

All data stays on your device. Cookie Lens:

  • Processes cookies locally in your browser
  • Never sends cookie values or sensitive data to any server
  • Stores only non-sensitive preferences (theme, layout, settings)
  • Includes optional request tracking that requires explicit permission

Quick Start​

  1. Install Cookie Lens from the Chrome Web Store.
  2. Open DevTools with F12 or Cmd+Option+I.
  3. Go to the Cookie Lens tab.
  4. Browse, search, and edit cookies for the current site.
  5. Use the tabs at the top to access Security, Privacy, Size, and Export features.

Next Steps​