Faster Sites with SWIS Performance

Since the very beginning, my goal has been to help you make your site faster, make your visitors happier, and achieve all the good things that come with happier visitors.

While image optimization has been my focus for over 8 years, I know there is more to site speed than just images. I’ve used a variety of tools and plugins over the years, and have found myself wanting more than they could deliver (or sometimes less).

More recently, I’ve started to build these things myself, a line of code here, a line of code there. Until I realized, we have a bunch of tools that could help other folks, if only it had a UI to bring it all together.

I’ve spent several months working to that end, and I am proud to introduce our newest plugin, SWIS Performance.

SWIS Performance

More Speed with SWIS

Every single feature in SWIS is something I use and recommend for making WordPress sites faster. And everything we add or change in SWIS will have to go through that same filter.

Page Caching

The most important thing you need with any WordPress site is page caching. I generally recommend using a web host that has built-in server-based caching, but if you’re just starting out with your site or business, that might not be in your budget.

So naturally, the first thing in SWIS is a page cache. Even better, this caching engine has a WebP mode that works with next-gen WebP images created by our EWWW Image Optimizer.

Of course, if your web host already has server-side caching, the SWIS cache will gracefully step out of the way and let your server take care of things.


Our new SWIS Performance plugin focuses mostly on non-image assets, since, you know, we have a plugin for images already. Maybe you’ve heard of it?

First, you can defer JS and CSS resources, so they aren’t blocking up the queue and the page shows up quicker for your visitors. SWIS can also strip out all the whitespace in your JS/CSS files, so they are as small as possible.

We’re not done there, because when you defer CSS, you need to have your critical (above the fold) CSS added inline. So SWIS has a handy text field where you can drop in your critical CSS.

If you server supports it, SWIS will even add gzip compression to all your JS/CSS assets, which can make a big difference in size, sometimes saving 90% or more. The plugin will additionally set expires headers on supported servers, to make sure browsers cache these “static” assets as long as possible.


But one of my favorite features is a little thing I like to call Slim. This lets you disable unused JS/CSS files on any page you like, or site-wide. If you have a contact form loading stuff site-wide, you can tell Slim that you only want the contact form bits to load on the contact page.

To assist you in finding out what JS or CSS is loading where and when and even why, there is an admin-bar menu to show all your JS/CSS resources. It helps you find out everything that is loading on a page along with what plugin or theme it comes from.

Slim also shows you JS/CSS dependencies, to help keep you from accidentally breaking your site by disabling a JS file that might be required by something else.

More Goodies

Halloween might be over, but we have a few more treats for you. SWIS can rewrite all your URLs to use a CDN on your site. It can optimize any Google Fonts used on your pages (automatically). Plus, it scans each page and adds DNS pre-fetch and pre-connect hints so visitors can load third-party assets quicker.

And if that isn’t enough, we included our image lazy loader, which has auto-scaling for responsive images. This helps make sure the images loaded on your page are the right size for each device, instead of using the (sometimes horrible) default sizes from your theme.

So if you want to make your site speedy, take SWIS for a spin. It’ll make your site faster, or your money back!

21 thoughts on “Faster Sites with SWIS Performance

    1. There are several things that SWIS does better:
      1. Automatic Google Fonts optimization.
      2. Disable unused JS/CSS (this is one of my favorites).
      3. WebP option for page cache supports background images and several other custom things that plugins do with images.
      4. Automatic DNS prefetch/preconnect detection.
      5. CDN rewriting is more thorough (uses the module we developed for Easy IO).
      Could be more, but that’s the main things I can think of off-hand.

      And here are some things SWIS is missing (and WP Rocket has) that I still want to implement:
      1. Cache pre-loading.
      2. Cache for logged-in users.
      3. Automatic generation of Critical (above the fold) CSS.

    1. You could, but about the only reason I would at this point is for Critical CSS generation (coming soon to SWIS).

  1. Hi Shane,
    Are you planning to introduce local hosting for Google Analytics and ideally the Facebook pixel? Similar to WP Rocket’s features? Thanks

    1. Not at this time, though you could suggest it here:
      To be clear, if a feature can improve site performance, then it will be considered if enough folks are interested. If it’s a privacy-only feature and does not improve performance, then it is out of scope for SWIS.

      1. OK thanks for coming back. The Google Analytics/Facebook Pixel local hosting are speed related features rather than privacy related. Though I see WP ROcket have just deprecated them in favour of using their “Delay JavaScript Execution” option. I’ll use your feedback facility. Cheers Shane.

    1. Some of the things in SWIS will of course be redundant with SG Optimizer, so I would recommend disabling them in SGO and only using it for the integration with Siteground’s caching system. In short, disable all of the JS/CSS/image options and use SWIS + EWWW IO instead.

    1. Hi Sarah, thanks for the question! There is no case where I would recommend using both plugins together. It’s worth noting, if someone is using the premium WPFC, there are some image optimization features, but of course our flagship plugin, EWWW Image Optimizer, provides those much better already.

    1. Hi, SWIS only includes page caching, but will work fine with whatever object cache you would like to use. My dev site has redis, and I can confirm it works with SWIS.

    1. SWIS includes an integration with, a service built by the guy who wrote the software used by most other plugins. I believe strongly in supporting his work, plus it gives you support from a team that are the experts when it comes to critical CSS.

  2. Hi Shane Bishop,
    Thank you for reply, one more question. Ewww CDN locations include Singapore or Malaysia?

    1. All plan levels include the Singapore location, even though the Standard level only lists US & EU. Our Growth and Infinite plans also include locations in Malaysia, Thailand, and Vietnam along with the entire Bunny network:

  3. Hi Shane,

    What’s “optimize any Google Fonts” mean exactly? Does it download + load the detected Google fonts from CDN, so it’s not loaded from Google?

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