Remove Query Strings from Static Resources (Deprecated)

In a URL, a query string, also referred to as a URL parameter, is anything that follows the question or ampersand symbol. These query strings are used to differentiate content. For example, if you are browsing an online catalog of shoes, you will see the query string change depending on which shoe you are looking at. They can also be used to track users as they navigate through your site. There are various kinds of parameters, such as active and passive. Active parameters are used to change on-page content depending on what the user does. Passive parameters do not change content. These parameters are used more for tracking (SEO, affiliate, campaigns, etc.) or assigning user session ID, for example.

This recommendation has been deprecated by PageSpeed because there were some web servers and proxy server providers that would prevent any URL that contained a question mark in the structure to be cached. Obviously, if you cannot cache pages, then it is going to take longer to load than if the page was cached in the user’s browser. Today, a lot of CDN and CMS providers will remove query strings, or provide a straightforward way to remove these query strings from URLs, so it is not much of an issue anymore. However, there are situations where query strings are necessary, like to indicate theme versions, so in those cases, they should not be messed with, or you risk breaking your site altogether.