Is WP-Optimize compatible with Cloudflare

Yes! No special configuration is needed. Page cacheing on the WP site (that done by WP-Optimize) is independent of proxy cacheing (e.g. Cloudflare) – you can use both, or neither, and they will complement eachother and not interfere.

Just one thing to note – Cloudflare will strip out the special HTML comment at the bottom of the source of a page that is helpful to confirm that page cacheing is working, so, don’t be confused by that – it’s absence doesn’t indicate it’s not working.

How does static file cache work

Static content is any content that can be delivered to an end user without having to be generated, modified, or processed. The server delivers the same file to each user, making static content one of the simplest types to cache and transmit over the Internet.

You can tell the browser to reuse a locally cached copy of these static files instead of requesting them from your server each time the page loads. Also if the file changes however the modified time on it changes and the browser is forced to fetch a fresh copy. This will not only save valuable bandwidth but also ensure a faster load time your visitors.

You can set the time for which these files are valid using the static file cache option in WPO. It is set to 28 days by default. Do note that this will work only if the user has a copy of the static file stored in the browser from an earlier visit to your site.

What is cache lifespan?

WordPress uses nonces as security tokens which are printed in the source code of the page. These nonces cannot be reused and are valid for 12 hours by default, but developers can change that value. The nonce getting invalidated can affect all kinds of functionality on the site like form validation or the visual appearance of a page among others.

Setting a cache lifespan to under 10 hours ensures the cache is flushed automatically once the nonce expires. This way you can use WPO cache on sites which use nonces.

The cache lifespan option is set to 10 hours by default, but you may have go down to 8 or even less. A lower cache lifespan value will result in more frequent cache update activity on your server, and thus more preload processes, if activated. If you notice any issues due to high server load, set a higher interval for the preloader.

What is Gzip compression?

When a user visits your website a call is made to your server to deliver the requested content. Gzip compresses your webpages and style sheets before sending them over to the browser. This drastically reduces transfer time since the files are much smaller.

Gzip compression is really effective because CSS files and HTML files use a lot of repeated text and have plenty of whitespace. Since Gzip compresses common strings, this can reduce the size of pages and style sheets by up to 90%.