How To Configure SiteGround’s SG Optimizer Settings (Including The Features It Doesn’t Have, And Which Plugins To Use For Them)

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Looking for the optimal SG Optimizer settings?

SiteGround made big improvements to their SG Optimizer plugin in March, 2018.

As they continue to update it and add more features, it’s now very comparable to WP Rocket (except for a few features it still lacks which I listed alternatives solutions for in this tutorial).

I even set up an Astra theme on a SiteGround GrowBig account to run speed tests on a demo site. When SG Optimizer was configured, I was able to get around a 1s to 1.5s load time with 99% + 94% PageSpeed and YSlow scores in GTmetrix (see the report). I guess SiteGround’s migration to Google Cloud servers, along with the big SG optimizer update, was a good thing.

A main benefit of SG Optimizer is that it uses server-side caching + binaries instead of file-based caching done by other cache plugins. In other words, SG Optimizer is more efficient.

If you haven’t signed up for SiteGround yet, using my affiliate link is appreciated. I wrote an honest review of SiteGround including both pros and cons of their hosting.


1. SuperCacher Settings

SiteGround’s SuperCacher has 3 layers of cache – static, dynamic, and memcached. StartUp only includes only one layer (static cache) while GrowBig and GoGeek come with all 3 layers – this is shown on their features page. Ideally, you want to enable all 3 layers of SuperCacher. By default, memcached is disabled and you will need to activate this using the instructions below.


Activating Memcached – to view your caching levels and activate memcached in SG Optimizer’s plugin settings, login to SiteGround and go to your SuperCacher settings.


Static Cachestatic cache is enabled by default for all plans. This caches static content.


Dynamic Cache – enable dynamic cache which caches dynamic (changing) content.


Memcached – enable memcached which primarily speeds up database queries. Once memcached is activated in your SiteGround account, it can also be activated in SG Optimizer.



2. Environment Optimization

Activate everything except for “fix insecure content” and test out PHP 7.4


Enable HTTPS – to add SSL, simply activate the free Let’s Encrypt SSL in your SiteGround account, then click “enable HTTPS” in SG Optimizer. SiteGround will automatically configure your site for HTTPS, and when you’re done, your website should have the lock icon in browsers.

Fix Insecure Content – if you see mixed content warnings in your browser when using SSL, it means you’re loading both HTTPS + HTTP. Enabling this can fix it, otherwise leave it disabled.

Set Your PHP Version – I recommend testing PHP 7.4 and checking your website for visible errors. If you don’t see any, stay on PHP 7.4, otherwise select the managed PHP option and SiteGround will automatically update this when a newer, stable PHP version is released. I guess PHP 7.4 isn’t stable yet, but it worked perfectly on my site and is slightly faster than PHP 7.3.


GZIP Compression – enables gzip (if enabled here, disable it in Cloudflare + CDNs).

Browser Caching – enables browser caching.


3. Frontend Optimization

Enable everything since these settings have the biggest impact on your GTmetrix scores.

Some settings contain warnings from SiteGround where you should check your website for visible errors. If you don’t see any, leave enabled. If you see any, the best option is to view your source code, find the problematic files, and exclude them in the defer render-blocking JS field. Otherwise, you can disable the setting(s) giving you errors, but your load time won’t be as fast.


Minify the HTML Output – fixes minify HTML in GTmetrix + PageSpeed Insights.

Minify JavaScript Files – fixes minify JavaScript in GTmetrix + PageSpeed Insights.

Combine JavaScript Files – combines JavaScript files into 1 single file to load faster.

Defer Render-Blocking JS – fixes remove render-blocking JS in PageSpeed Insights.

Minify CSS Files – fixes minify CSS items in GTmetrix + PageSpeed Insights.

Combine CSS Files – combines CSS files into 1 single file to load faster.

Optimize Loading Of Google Fonts – combines Google Font files to load faster. If you’re using Google Fonts, you should also try hosting fonts locally and using the OMGF plugin which may improve font load times. GTmetrix has a fonts section in the Waterfall so be sure to check that.

Remove Query Strings From Static Resources – item in GTmetrix but is usually caused by plugins, so be sure to check your GTmetrix report to see which plugins are causing these errors. Enabling this may help, but using the right (lightweight) plugins is the best way to solve this.

Disable Emojis – emojis hurt your load times.


4. Media Optimization

The Media Optimization settings help make images, videos, iframes, and Gravatars to load faster. The only thing it doesn’t do is serve scaled images (making sure you’re using the right image dimensions and not uploading huge images) which has to be done by you, not a plugin.


New Images Optimization – losslessly compresses images which should fix the optimize images item in GTmetrix. I wish SiteGround had options for compression levels and WebP.

Existing Images Optimization – losslessly compresses existing images, but take a backup of your website first! In the chance you do see a loss in quality, at least you will have a backup.

Lazy Loading – delays loading of iframes, videos, Gravatars, and images until users scroll down the page and see them. This improves initial load times and is recommended in nearly speed testing tools. I have never been able to improve Gravatar scores (so I have them disabled) even when testing SG Optimizer, WP User Avatar, and even the wpDiscuz Gravatar Caching options.



5. Performance Test

Tests your website in Google PageSpeed Insights. Here are my results on the demo site.



Functionality SG Optimizer Still Lacks

There are still optimizations SG Optimizer lacks which have to be done by other plugins.

Heartbeat Controldisable WordPress heartbeat manually (by adding a code to your functions.php file file) or use a plugin like Heartbeat Control, Perfmatters, or WP Rocket.


Cleaning Database – clean junk files from your database using WP-Optimize or WP Rocket. I like WP-Optimize because it lets you delete unused plugin tables left behind by old plugins.


Prefetch + Preconnect – makes third party scripts and fonts load faster by prefetching + preconnecting them with Perfmatters, WP Rocket, or the Pre* Party Resource Hints plugin.


Remove Bloat – remove unnecessary bloat (including Heartbeat) using Perfmatters by Kinsta or Clearfy. I recommend Perfmatters since it’s lightweight and lets you remove tons of stuff, and it has a script manager for selectively disabling plugins, also not included in SG Optimizer.


Selectively Disable Plugins – disable scripts/plugins from running on specific pages and posts (for example, disabling contact forms on all pages but the contact page, or disabling social sharing on pages). There’s a script manager included with Perfmatters if you’re already using it to remove bloat, otherwise use Asset CleanUp. This can significantly improve load times (and scores) especially if you’re running lots of plugins that don’t need to load on every single page.


CDN URL Integration – add a CDN URL from StackPath, KeyCDN, and other CDNs. Cloudflare does not require a CDN URL since it can be activated in SiteGround. But in order to use other CDNs, they provide you with a CDN URL which you can paste in CDN Enabler or WP Rocket.


Hosting Google Analytics Locally – fix the “leverage browser caching” GTmetrix issue for Google Analytics using CAOS Analytics, Perfmatters, or WP Rocket’s Google Tracking addon.

Better Image Optimization Settings – SG Optimizer doesn’t let you control image compression level or have WebP support, while plugins like ShortPixel, Imagify, and Smush do support these.




Multisite Settings

Check the Global Settings and Per Site Defaults in their multisite tutorial.

The following must be the same for all your sites (shown in their global settings):

  • PHP version control
  • GZIP compression
  • Browser caching
  • Memcached


Other SG Optimizer settings can be customized (shown in their per site defaults):



Can I Delete My Old Cache Plugin?

Yes, but do your testing make sure you have plugins like WP-Optimize and Perfmatters for cleaning your database and removing bloat, which SG Optimizer doesn’t have functionality for.




Avoid Duplicate Functionality

If you keep WP Rocket or another cache plugin, disable page caching using the helper plugin since you only want to use 1 plugin for caching (and avoid duplicate functionality in general). If you activated Cloudflare in SiteGround, the default settings should work perfectly, but I would still configure page rules, enable hotlink protection, and test Brotli, Railgun, and Rocket Loader.

SG Optimizer should automatically disable duplicate functionality:



Did I Miss Anything?

Let me know in the comments.

See Also: How I Got 100% GTmetrix Scores


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