Cookie Lens

Privacy-first Chrome DevTools extension for inspecting, editing, parsing, monitoring, mocking, and exporting browser cookies.

Cookie Lens is a cookie editor, manager, and debugger built into Chrome DevTools. It shows every cookie change as it happens — including the Set-Cookie headers Chrome silently rejects, with the exact reason — and decodes JWT, Base64, and JSON values right in the table. WHY COOKIE LENS Most cookie extensions list and delete cookies. Cookie Lens treats them as a first-class debugging surface: - Live activity feed — a "network tab for cookies": set, update, delete, expire, and evict events for the inspected tab, with value diffs. - Rejected-cookie detection — when the browser silently drops a Set-Cookie (SameSite=None without Secure, __Host-/__Secure- prefix violations, oversized headers, a Domain the host can't set, third-party blocking), Cookie Lens surfaces it with the reason. The bug you can't see today becomes one line in the feed. - Freeze — pin a cookie's value; a background enforcer instantly reverts any page or server change or deletion. Ideal for testing feature flags, A/B buckets, and session edge cases. - Profiles — save the current cookie set under a name and switch between test scenarios in one click. Export and import profiles as files. - Consent (GDPR) analysis — reads your consent manager's own cookie (OneTrust, Cookiebot, CookieYes, Osano, Didomi, IAB TCF) and flags cookies written against — or before — the user's recorded consent. - Security report — scores the site's cookies and lists concrete fixes for risky or misconfigured ones. EVERYTHING YOU EXPECT FROM A COOKIE EDITOR - Inspect, search, filter, sort, and pin cookies for the current site - Edit values and every attribute: domain, path, expiration, SameSite, Secure, HttpOnly - Auto-decode structured values — JSON, URL-encoded JSON, Base64, JWT, query strings, key-value formats — and edit them safely in decoded form - Smart search that also matches decoded values (JWT claims, Base64 text), with a chip explaining the match - Detect expired, oversized, risky, or misconfigured cookies at a glance - See which network response set or updated a cookie - Snapshot and diff cookie states between two moments - Export as JSON or CSV; import with validation and clear per-cookie error reporting - Value masking and incognito support (separate cookie jar) Built for frontend engineers, QA engineers, backend engineers, web platform teams, and anyone debugging cookies, sessions, or consent behavior in modern web applications. PRIVACY-FIRST BY DESIGN Cookie Lens processes everything locally in your browser. It does not send cookie values, authentication tokens, JWTs, session identifiers, browsing data, request or response bodies, or exported files to any remote server. Host access is not granted by default: Cookie Lens requests access per site, only when you ask, from a user gesture. Persistent local storage holds your preferences — theme, table layout, pinned cookie identifiers, and feature settings. When you use Freeze or Profiles, it additionally stores the cookie snapshots those features need in order to restore values later; because that is their purpose, these snapshots include cookie values. Everything stays on your device and is never transmitted. "Set by request" attribution runs only for sites you have granted access to. It reads response headers in memory to link a cookie to the request that set it — these headers are never written to disk and never leave your browser. Cookie Lens is not just a cookie editor. It is a DevTools-native cookie debugging, parsing, export, and audit workspace.