Cookie
About 4 min read
Last updated: 2026-01-25
What Are Cookies
A cookie is a small piece of text data that a website stores in the user's browser. By reading this data on subsequent visits, websites can maintain login sessions, preserve shopping cart contents, and remember language preferences.
Cookies were invented in 1994 by a Netscape engineer to overcome the limitation of HTTP being a stateless protocol. Today's web depends on cookies for everything from login functionality to personalization.
Types and Roles of Cookies
Cookies and Privacy
Cookies became a privacy concern primarily because of cross-site tracking through third-party cookies. Ad networks set third-party cookies via tracking pixels embedded across multiple sites, recording users' browsing behavior in detail.
In response, the GDPR (EU General Data Protection Regulation) mandated that websites obtain explicit user consent before setting cookies. In Japan, the amended Act on the Protection of Personal Information also requires consent for providing personal-related information, including cookies, to third parties.
Browsers have also taken action: Safari blocks third-party cookies by default through ITP (Intelligent Tracking Prevention), and Chrome is gradually phasing out third-party cookies from 2025 onward.
How to Manage Cookies Safely
- Regular deletion: Periodically deleting cookies from your browser settings resets accumulated tracking data.
- Block third-party cookies: Blocking third-party cookies in your browser settings significantly reduces cross-site tracking. Most websites will continue to function normally.
- Cookie management extensions: Extensions like Cookie AutoDelete can automatically remove unnecessary cookies when you close a tab.
- Do Not Track setting: Enabling your browser's DNT setting signals websites that you prefer not to be tracked. However, compliance by websites is voluntary.
To learn more about this topic, see Cookies and Tracking: How Your Online Behavior Is Being Monitored.
Common Misconceptions
- Cookies are a type of virus or malware
- Cookies are simply text data and have no ability to execute programs. However, when used for tracking purposes, they can impact your privacy.
- Disabling all cookies makes you safe
- Completely disabling cookies will break basic website features like login and shopping cart functionality. A practical approach is to block only third-party cookies while allowing first-party cookies.