Session ID

Definition

A session ID is a unique identifier that is assigned to a user when they visit a website. The session ID is used to track the user's activity on the website and maintain state across different pages.[1]

Session ID storage

Session IDs are often stored in a cookie, which is a small piece of data that is stored on the user's device. When the user requests a new page on the website, the session ID is sent back to the server in the request header, allowing the server to associate the request with the user's session. This allows the website to maintain state, such as remembering items in a shopping cart or user preferences, as the user navigates from page to page.

Session IDs can also be stored in the URL as a query parameter, or they can be passed in the body of a POST request. In these cases, the session ID is not stored on the user's device, but it is still sent with each request to the server, allowing the server to maintain state for the user.

Session ID usage

Session IDs are commonly used to track user activity on a website and maintain state, but they can also be used for security purposes, such as to prevent cross-site request forgery (CSRF) attacks.

Relevance to SEO

Session IDs are not directly relevant to search engine optimization (SEO). Session IDs are used by websites to track user activity and maintain state, but they are not used by search engines to crawl or index web pages.

However, session IDs can potentially have an indirect impact on SEO if they affect the user experience or the performance of a website. For example, if session IDs cause the URLs of web pages to change frequently, it could make it more difficult for search engines to crawl and index the pages. This could potentially negatively impact the visibility of the website in search engine results.

In addition, if session IDs cause pages to load slowly or negatively impact the user experience in some other way, it could lead to a higher bounce rate, which could hurt the website's search engine rankings.

Related links

[GA4] About Analytics sessions

Google Bigquery - Get the ID of your active session