Should I be deleting them?
What is a cookie?
When you visit a website, the server will send you the web page you requested, but it might also send you a cookie. The cookie is a small packet of data that will get stored on your computer. This information can improve the user experience when visiting the site again. Cookies are used to personalize your experience on websites, but they might contain private or personal information. They can include data such as user preferences, session state, login credentials, shopping cart contents etc.
Benefits of clearing your cookies
Whilst first-party cookies aren’t usually harmful, clearing your cookies and browser history on a regular basis can prevent that personal information from falling into the wrong hands. It might also improve the performance of your device and your browser, freeing up memory.
Third-party cookies
Third-party cookies however, are not as innocent as the first-party cookies we just talked about.
Third party cookies are cookies that are set by a website other than the one the user visited.
They are used to target specific ads. They might seem like an invasion of privacy. They also tend to be less secure than cookies from specific sites.
How do they end up on our browser?
01
Embedded Content
If you visit a website that contains content (e.g. videos, images etc) from third-party domains, those resources can set cookies in your browser.
02
Cross-Site Requests
Your browser may make a request to a third-party domain while you are visiting a website.
03
Tracking Pixels & Scripts
They are provided by third-party analytics or advertising services. They can execute code in your browser allowing the third party to set cookies and track your activity across multiple websites.
04
Redirects
If you are redirected to another website, that new website may set cookies in your browser.
05
Subdomains
If you visit www.example.com, a subdomain might be subdomain.example.com and the cookie it sets is considered a third party cookie.
Modern web browsers provide options to manage cookies, including options to block or limit third-party cookies.
Furthermore Google has said that by Q3 of 2004, it will ramp up third party cookie restrictions to 100% of users.