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Building a Cookie Editor Chrome Extension — Why I Built CookieJar After EditThisCookie Died

EditThisCookie Is Gone — Now What?

In late 2024, EditThisCookie — the most popular cookie editor for Chrome with millions of users — was removed from the Chrome Web Store. The reason: it never migrated to Manifest V3.

Overnight, millions of developers and testers lost their go-to cookie management tool. I saw an opportunity and built CookieJar — a modern, MV3-native cookie editor with features EditThisCookie never had.

What CookieJar Does Differently

1. Automatic Cookie Classification

EditThisCookie showed you a flat list of cookies. CookieJar automatically classifies every cookie into 6 categories:

  • Essential — Session tokens, CSRF tokens, auth cookies
  • Functional — Language preferences, UI settings
  • Analytics — Google Analytics, Mixpanel, Hotjar trackers
  • Advertising — Facebook Pixel, Google Ads, retargeting cookies
  • Social — Social media widgets, share buttons
  • Unknown — Unclassified cookies

Classification uses a combination of:

  • Pattern matching on cookie names (e.g., _ga → Analytics)
  • Domain matching against the Disconnect.me tracking list
  • Heuristic analysis of cookie attributes (HttpOnly, SameSite, expiry)

2. Privacy Score

Every site gets a 0-100 privacy score displayed as a circular gauge in the popup header. The score factors in:

  • Number and type of tracking cookies
  • Presence of third-party cookies
  • Cookie security attributes (Secure, HttpOnly, SameSite)
  • Total cookie count relative to category average

A developer can instantly see whether a site's cookie practices are reasonable.

3. Profile Management

Save and restore cookie sets as profiles:

  • Testing multi-role authentication? Save "Admin" and "User" profiles
  • Switching between staging and production? One click
  • Debugging OAuth flows? Save pre-auth and post-auth states

4. Export Formats

CookieJar exports cookies in 5 formats:

  • JSON (for programmatic use)
  • Netscape/curl format (for cURL commands)
  • HTTP Header format (for direct API testing)
  • Puppeteer format (for automation scripts)
  • CookieJar format (for import into another CookieJar instance)

Technical Architecture

MV3 Cookie Access

In MV3, cookie access requires the cookies permission and proper host permissions:

{
  "permissions": ["cookies", "storage"],
  "host_permissions": ["<all_urls>"]
}
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The chrome.cookies API provides methods for reading, setting, and removing cookies. CookieJar wraps these in a type-safe abstraction layer.

Real-Time Updates

CookieJar uses chrome.cookies.onChanged to show real-time cookie updates without polling. When a site sets, modifies, or deletes a cookie, the popup updates instantly.

Performance

With sites sometimes having 50+ cookies, rendering performance matters. CookieJar uses:

  • Virtual scrolling for large cookie lists
  • Debounced search filtering
  • Lazy classification (classify on first view, cache results)

8-Language Localization

CookieJar ships with full localization in:
English, Japanese, Chinese (Simplified), Korean, Spanish, French, German, Portuguese

All UI text goes through a localization system — no hardcoded strings.

Privacy Commitment

CookieJar itself collects zero data. No analytics, no tracking, no server communication. All cookie data stays in your browser. The irony of a cookie management tool that tracks you would not be lost on developers.

Installation

CookieJar is free and available on the Chrome Web Store.

Pro features (profile management, bulk operations, export) are available for $4.99/month.


Built by S-Hub — Chrome extensions for developers and productivity enthusiasts.

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  • DataBridge — Transfer data between web apps

See all extensions at dev-tools-hub.xyz

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