The are two options in Joomla to clear cache files from the cache folders if enabled under the Site Global Configuration settings.
- Clear Cache – This tool will delete all Cache files from the cache folders – including current ones – from your web server.
- Clear Expired Cache – This tool will purge all expired cache files from the cache folders.
So, what the difference ?
How to clear cache in Joomla
Step 1. Click on System => Clear Cache
Step 2. Select all Cache Croup check box .
Step 3. Click on Delete Button.
As admin functions are cached too, some cache folders might appear as if they were not cleaned because they get recreated before cache content is re-scanned after this action.
Cache files are temporary files that are created to improve the performance of your site. If you have made significant changes to your web site, such as changing your Template or Language, your cache files may be out of date. To avoid any problems caused by out of date cache files, you can delete all of the cache files.
- Because this process deletes all Cache files, the website may be a little slower immediately after running Clean Cache. Once this process is complete, users lose the benefit of using the cache files until they are re-created by Joomla! to be up to date with your current site.
- In contrast, the Clear Expired Cache option will check each Cache file individually for being out of date, but the process is slower and requires more system resources. However, the website should perform close to the same speed for users visiting your site, since all up to date files are still available for your current Joomla! site.
We recommend to check and clear cache in development process, to avoid miss-configurations in the internet browsers after editing files or articles. In fact some browsers still can hold old cache data even after Joomla cache has been done. In this case first step is refresh browser by clicking F5 button on your keyboard. If it doesn’t help you can clear cache in browser, usually it call delete history function.
How to clear expired cache in Joomla
Step 1. Click on System => Clear Expired Cache.
Step 2. Click on Clear Expired Cache button.
This tool will purge all expired cache files from the cache folders. Cache files are temporary files that are created to improve the performance of your site. Cache files that are still current according to what Joomla! finds are not purged.
- Because this process has to check each cache file individually, it is slower and requires more system resources. Once the purge process is complete there should be no loss in speed for your users, because all up to date cache files are still available for your current Joomla! website.
- In contrast, the Clear Cache option runs more quickly since it deletes all of the files stored in each cache folder. However, the website may be a little slower immediately after running Clean Cache, since all cache files — including current ones — are removed, so users lose the benefit of using the cache files until they are re-created by Joomla!to be up to date with your current site.
- If you have a large number of cache files and your server setting for ‘max_input_time’ is set to less then 60 seconds, you may receive a PHP warning message saying that the process exceeded the maximum time allowed. In this case, no harm is done but all of the files may not have been purged. It is ok simply to re-run the process.