What is cache memory and a hard refresh?
When you use a browser, such as Chrome, information from websites is stored in cache memory and cookies. Cache memory is a storage area where data is temporarily stored to allow faster access to that data.
When we make changes and "put them live," you may not see them right away when you visit the page. In most cases, this is due to your browser's cache memory. This means that your browser stores pieces of your previous visit to the page in question and requests them again on your next visit to speed up the loading of the page. Therefore, your browser may display an outdated version of the page.
You can fix this by performing a so-called 'hard refresh'. Depending on your browser, you can do this with the following key combinations.
Chrome Mac: hold ⌘ Cmd and ⇧ Shift key and then press R
Chrome Windows: hold down Ctrl and then press F5.
Mozilla Firefox and related browsers Mac: hold ⌘ Cmd and ⇧ Shift key and then press R.
Mozilla Firefox and related browsers Windows: hold Ctrl, then press F5.
Microsoft Edge: hold Ctrl and then press F5.
Internet Explorer: hold Ctrl and then press F5.
Important: Internet Explorer will no longer receive support and/or updates as of June 15, 2022, so it is recommended for security reasons to use another browser such as Chrome or Edge!
With browser caching, the browser is going to look for files that it has requested from the server before. If so, it is going to retrieve these files locally from the user instead of sending a request to the server.
Because browsers go to see if they already have the files, and they are displayed even before a request to the server happens, the website cannot tell the browser in time that there is new content.
Therefore, we assign an expiration date to each type of file.
For example: if a page needs a javascript file, we give this javascript file that the browser may cache this file for one month. Images are an exception: we cache them for one year.
After that, a new request must be made to the server for this file.