Cookie basics
Guides, demos and tools to help you understand how cookies work.
What are cookies?
Understand HTTP cookies: how they're set by a web server, then stored and sent by a web browser.
Third-party cookies
A third-party cookie is from a site that's different from the site you're visiting. What does that mean in practice?
Cookie blocking
Cookies can be blocked by browser design, Enterprise policy, or user choice. This article explains how.
Cookie tools
Chrome tools to help you understand cookie usage on your site.
In depth
Cookie attributes
Cookies can include attributes to control if they're set, and when they expire.
HTTP request and response
The web uses the HTTP protocol to transfer resources and set cookies. How does that work?
Cookie demos
First-party cookies, third-party cookies, cross-site tracking.
Basic cookie
demos
First-party cookie demo
Cookies are set in response to requests for the image and iframe on the demo page.
👉 1pc.glitch.me
👉 1pc.glitch.me
Third-party cookie demo
The demo page includes an image and an iframe from a different (third-party) site.
👉 3pc.glitch.me
👉 3pc.glitch.me
JavaScript cookie demo
JavaScript included on this page sets a cookie.
👉 javascript-cookie.glitch.me
👉 javascript-cookie.glitch.me
SameSite cookie demo
Both sites set a cookie in response to requests, using the default SameSite value Lax.
👉 samesite-a.glitch.me
👉 samesite-b.glitch.me
👉 samesite-a.glitch.me
👉 samesite-b.glitch.me
Cookie tracking
demos
Cross-site cookie tracking demo
Tracking pixel demo
Both pages include a single-pixel image, which allows a cookie to track activity on sites that include the image.
👉 tracking-pixel-a.glitch.me
👉 tracking-pixel-b.glitch.me
👉 tracking-pixel-a.glitch.me
👉 tracking-pixel-b.glitch.me
Fetch cookie demo
JavaScript included on this page makes a cross-site fetch() call, which sets a cookie in response.
👉 fetch-cookie.glitch.me
👉 fetch-cookie.glitch.me