- Many of them modify your htaccess file: You may not aware of it but many cache plugins of WordPress modify your htaccess without warning you about it. We never know the consequences of modifying htaccess.
- They modify the HTTP headers response of your files: The http headers are meta information about your page. Example of HTTP headers:
HTTP/1.1 200 OK Date: Sun, 22 Oct 2017 14:21:24 GMT Server: Apache Upgrade: h2,h2c Connection: Upgrade Cache-Control: max-age=0 Expires: Sun, 22 Oct 2017 14:21:24 GMT Content-Type: text/html; charset=UTF-8
- Some of them have security holes: Yoast has reported a vulnerability in W3 total cache. This vulnerability has been reported in 2016. However, W3 total cache exists since at least 6 years.
- Incompatibility with many plugins: We have found that many cache plugins aren’t compatible with many plugins. It can generate 500 server errors for some web pages and you may not aware of it because the homepage is working well.
- Incompatibility with many themes: There are reports of webmasters who faced problems with cache plugins. Here is one example with Wp super cache.
As you can see, using a cache plugin in WordPress has many consequences.
Don’t listen to the hype when people tell you to install a cache plugin to speed up your WordPress installation. For instance, if you have a WordPress installation in Hungarian, you don’t need a cache to speed up your WordPress installation as your visitors are close-by.