Preventing Server-side CSS File Caching with Apache

When developing websites, it is crucial to ensure that visitors are accessing the latest versions of CSS files to prevent caching issues. This article addresses the question of whether Apache caches resources and provides a solution to prevent it from doing so, especially when encountering a scenario where CSS changes are not reflected in the browser despite reloading the page.

Is it true that Apache caches resources?

Yes, Apache can cache resources such as CSS files to improve page load times. This behavior is primarily controlled by the mod_expires module, which specifies expiration dates for different file types. To check if Apache is caching CSS files on your server, you can use the following steps:

1. Open a command prompt or terminal window.
2. Navigate to the Apache configuration directory (usually /etc/apache2).
3. Edit the .htaccess file in the public_html directory.
4. Add the following code:

ExpiresActive On
ExpiresDefault "access plus 0 seconds"
ExpiresByType text/css "access plus 0 seconds"

5. Save the file and restart Apache.
6. Open the browser and refresh the page. If the CSS file has been updated, you should see the changes immediately.

How to prevent Apache from caching CSS files?

To prevent Apache from caching CSS files, you can set the expiration date for CSS files to a short duration, such as zero seconds. By doing this, the browser will always fetch the latest version of the CSS file from the server instead of using the cached version. Here's how you can do it:

1. Locate the .htaccess file in the public_html directory.
2. Add the following line:

ExpiresByType text/css "access plus 0 seconds"

3. Save the file and restart Apache.

Alternatively, you can use a query string to force the browser to reload the CSS file every time it is requested. For example, you can change your CSS link to the following:

When you update the CSS file, increment the value of the v parameter to force a reload.