The Ideal SiteGround Optimizer Settings 2023: Disable Most Settings, Then Use A Different Plugin For Better Core Web Vitals

Ugh, SiteGround Optimizer.

I’ll show you how to configure SiteGround Optimizer’s settings, just know it does a poor job with web vitals, especially LCP and CLS. You can’t preload images, remove unused CSS, delay JavaScript, specify image dimensions, host fonts locally, and it still doesn’t support critical CSS.

For better results, you should also use FlyingPress, Perfmatters, or both (you could use WP Rocket, but I recommend the previous two). I’ll also show you how to configure these with SiteGround Optimizer including duplicate settings + new features to optimize your site. You’ll still use SiteGround Optimizer’s dynamic caching + Memcached, but not for most other settings.

Another reason not to use it is compatibility issues which support often blames on third-party plugins. Just search their support forums for “Elementor” or other plugins/themes you’re using.

And even after SiteGround’s CDN v2, I still don’t recommend using their CDN because you risk your DNS getting blocked by Google which at least for me, would be devastating. While I don’t have tests measuring it’s performance (yet), I highly doubt it beats Cloudflare’s APO for $5/mo.

You can probably tell I don’t like SiteGround, and you’re right. Not only do they hype up products when they’re clearly inferior to similar ones (including their hosting), but they hide bad reviews by threatening people and controlling Facebook Groups to promote their services.

But that’s a different story. For now, let’s just configure this thing.

 

1. Dashboard

Here’s why you don’t need perfect scores (4/4/, 3/3, 6/6, 3/3):

File-based caching overlaps with page caching in other cache plugins, so only enable it in 1 (browser caching also overlaps and is usually easier to disable using SiteGround Optimizer). Dynamic caching can have compatibility issues when using APO, but leave on otherwise. All SiteGround’s CSS settings should be left off when using “remove unused CSS” in plugins like Perfmatters/FlyingPress. SiteGround Optimizer’s lazy load settings lack many features with frequent compatibility issues. For this, I recommend either Perfmatters or FlyingPress which can also preload critical images (for better LCP scores) and lazy load CSS background images.

Other common overlapping features are Heartbeat control, defer JavaScript, and minifying CSS/JS. You can use SG Optimizer for these, then disable them in other optimization plugin(s).

FlyingPress/Perfmatters also have many lacking features not found in SiteGround Optimizer: delay JavaScript, font-display: swap, add missing image dimensions, and host fonts locally. FlyingPress can also lazy render HTML elements and self-host YouTube placeholders while Perfmatters can remove bloat, preload CSS/JS files, and includes a script manager to reduce CSS/JS by disabling plugins on pages/posts they’re not used. For best results, I suggest both.

Finally, use WP-Optimize to clean your database which can remove tables left behind by old plugins, take backups, and keep a few post revisions (instead of deleting them all). All that said, SG Optimizer works best when combined with FlyingPress, Perfmatters, and WP-Optimize.

There’s still 1 key lacking feature which can improve mobile/LCP scores, and that’s resizing images for mobile which SiteGround Optimizer (and their CDN) don’t support. You can try ShortPixel Adaptive Images or image CDNs like Bunny Optimizer or Cloudflare’s image resizing.

I know it’s confusing, but with so many lacking features, you’re forced to compensate by using other plugins to get the best results. If you have any questions about this, leave me a comment.

	SG Optimizer	WP Rocket	FlyingPress	LiteSpeed Cache
Server-side caching	✓	x	x	✓
Object cache integration	✓	x	x	✓
Delay JavaScript	x	✓	✓	✓
Remove unused CSS	x	Inline	Separate file	Separate file
Critical CSS	x	✓	✓	✓
Preload critical images	x	x	✓	x
Exclude above the fold images	By class/type	By URL/class	Automatic	Automatic
Lazy load background images	x	Inline HTML	lazy-bg class	x
Add missing image dimensions	x	✓	✓	✓
Lazy load iframes	x	✓	✓	✓
YouTube iframe preview image	x	✓	✓	✓
Self-host YouTube placeholder	x	x	✓	x
Host fonts locally	x	x	✓	✓
Font-display: swap	x	✓	✓	✓
Preload links	x	✓	✓	✓
Bloat removal (beyond Heartbeat)	x	x	✓ (read details)	x
Lazy render HTML elements	x	x	✓	✓
Guest Mode	x	x	x	✓
Advanced cache control	x	x	x	✓
Gravatar cache	x	x	x	✓
Limit post revisions	Delete all	Delete all	Delete all	Keep some
CDN	Google Cloud	StackPath	BunnyCDN	QUIC.cloud
CDN PoPs	176	73	114	80
Full page caching	✓	x	x	✓
CDN geo-replication	x	x	✓	x
CDN image optimization	x	x	✓	✓
CDN image resizing for mobile	x	x	x	✓
CDN DDoS protection	x	x	✓	✓
CDN bandwidth	Unmetered	Very limited	Unlimited	Unlimited
Documented APO compatibility	x	x	✓	x
Documentation	Not detailed	Good	Not detailed	Good
New features	Infrequent	Infrequent	Frequent	Frequent
Facebook group	Join	Join	Join	Join
CDN price	$14.99/mo	$8.99/mo	$.03/GB	$.02-.08/GB
Plugin price	Free	$59/year	$60/year	Free
Renewal price	Free	$59/year	$42/year	Free

 

 

2. Caching Settings

If you’re using another cache plugin with SiteGround Optimizer, disable file-based caching and only use it for dynamic cache/Memcached. With Perfmatters or only SG Optimizer, enable all 3.

• Dynamic Caching: On – leave dynamic caching on unless you use Cloudflare APO, then leave it Off since there have been several compatibility issues which SiteGround denies.
• File-based Caching: On – leave Off if you’re using FlyingPress or WP Rocket. You could also disable WP Rocket’s caching using their helper plugin, but the first option is easiest.
  • Cleanup Interval: 1 week – expiration for file-based caching until it’s purged.
  • Preheat Cache: On – artificially fills the cache so visitors get a better cache hit ratio (similar to preloading in WP Rocket). Once the cache is purged, it’s preloaded using your sitemap and is executed with cron. This can increase CPU usage if you’re not careful and leaves little customization room, so keep an eye on your CPU usage.
  • Logged-in Users Cache: Off – only enable if you have user-specific content where visitors need their own cached version (membership sites for example). There are no customization settings / helper plugins and this also increases the stored cache size.

• Memcached: On – enables Memcached object cache which speeds up database queries. You will first need to activate Memcached in Site Tools (Speed →  Caching → Memcached).

• Automatic Purge: purges the cache when specific changes are made to your website according to SiteGround’s rules. There’s been several reports of this not working, so make sure it is. A full purge is done during larger changes (updating WordPress plugins/core or deleting a category) while a smart purge is done for smaller updates (modifying a post or adding a comment). Dynamic and file-based caching must both be enabled for it to work.
  • Purge WordPress API Cache: On – also purges the Rest API which is used on many websites including the block editor. If you don’t use Rest API, you can leave this off.
• Manual Cache Purge: usually only needed when automatic purge isn’t working for you.
• Exclude URLs From Caching: exclude URLs from dynamic and file-based caching. The documentation shows the example of the /cart/ page being excluded, so I assume they don’t automatically exclude URLs and you will need to do these manually. You can also use wildcards to exclude specific sections of your site, such as: abc.com/category/seo*
• Browser-Specific Caching: Off – SiteGround recommends only enabling this if you’re having issues with plugins or things like generating the mobile version of your website.
• Testing the cache – I recommend uptrends.com for testing the cache in SiteGround Optimizer and your CDN. They also have some documentation on testing the CDN cache.

 

3. Environment Settings

I recommend disabling scheduled database maintenance and use WP-Optimize instead. Also make sure you only use one plugin for Heartbeat Optimization, then disable it in other plugins.

• HTTPS Enforce: On – automatically force visitors to use a secure HTTPS connection. I assume most of you will be using the free Let’s Encrypt SSL you get through Site Tools.
• Fix Insecure Content: Off – if you see mixed content warnings in your browser when using SSL, it means you’re loading both HTTPS + HTTP. This can fix it, leave off otherwise.
• GZIP Compression: On – compress pages (Brotli is only available on SiteGround’s CDN).
• Browser Caching: On – stores static files in the browser so they can be accessed quicker. This should be left off when using other cache plugins which also have browser caching.
• WordPress Heartbeat Optimization: Disabled, 120s, Disabled – the only place you usually want Heartbeat is the post editor (posts and pages) since it handles things like autosaves to prevent you from losing work. Then disable it in the admin and frontend. Otherwise, the WordPress Heartbeat API will run every 15-60s and increases CPU usage.
• Scheduled Database Optimization: Off – WP-Optimize does a better job since you can take database backups via UpdraftPlus, keep a few post revisions (instead of deleting them all) and remove tables left behind by old plugins you deleted. When viewing tables, you may also notice certain plugins/modules add overhead, so consider disabling those.

 

4. Frontend Settings

Minify files, but don’t combine them.

SiteGround Optimizer can’t remove unused CSS or delay JavaScript while plugins like Permfatters, FlyingPress, and WP Rocket can. I recommend enabling “remove unused CSS” in one of those plugins and disabling all CSS settings in SiteGround Optimizer. I also recommend enabling “delay JavaScript” and configure SiteGround Optimizer’s JavaScript settings normally.

• Minify CSS/JavaScript/HTML: On – even when using Cloudflare’s APO, you should use your cache plugin to minify files which removes whitespaces and makes the files smaller.
• Exclude From Minification: if certain minify settings break your website, you’ll need to view your source code, find the problematic files, then exclude them from minification.
• Combine CSS/JavaScript: Off – most websites shouldn’t combine files for several reasons. It can often result in slower load times and have issues with HTTP/2 + HTTP/3.
• Exclude From Combination: no need to do anything here unless the combine setting is turned on and you need to exclude specific CSS, JavaScript, or HTML files from combining.
• Preload Combined CSS: Off – if you combined CSS, this preloads the file to load faster. But again, since most websites shouldn’t combine, this setting should also be disabled.
• Defer Render-Blocking JavaScript: On – fixes render-blocking resources but can break your site, in which you’ll exclude files. You can both defer JavaScript (in SG Optimizer) and delay JavaScript (in your other optimization plugin) since they’re different optimizations.
• Exclude From Deferral Of Render-Blocking JS: if deferring JavaScript breaks your site, exclude broken files. Check support threads for issues with WooCommerce/page builders.

• Web Fonts Optimization: On – combines fonts, loads them inline asynchronously, preloads them, and preconnects third-party fonts. I highly recommend opening your Waterfall chart and make sure fonts are self-hosted (not using fonts.gstatic.com), using woff2, and font-display: swap for lower CLS. Font icons can also create requests and page builders (Elementor) can disable unused fonts/font icons, or use custom fonts/font icons.
• Fonts Preloading: only self-hosted fonts can be preloaded. Look at the font files in your GTmetrix Waterfall chart, copy the URLs of all fonts loading above the fold (or mentioned in CSS files), then preload them. Test results since preloading too many fonts can have a negative effect. Retest your site and your font’s blocking time (brown bar) should go down.

• Remove Query Strings From Static Resources: On – deprecated GTmetrix item.
• Disable Emojis: On – removes JavaScript code needed to convert emojis (if you need them, just use Unicode). Most optimization plugins disable emojis, so only use 1 plugin.
• DNS Pre-fetch For External Domains: Usually Empty – delaying JavaScript is more effective. Third-party fonts and CDN URLs should use preconnect instead, so the only third-party domains you should prefetch are those not being delayed/preconnected.

### Popular JavaScript Files To Delay In Other Optimization Plugins ###
https://platform.twitter.com/widgets.js
https://connect.facebook.net/en_US/fbevents.js
https://www.google-analytics.com/analytics.js
https://www.googletagmanager.com/gtm.js
https://www.googletagmanager.com/gtag/js
https://www.googletagservices.com/tag/js/gpt.js
https://www.googleoptimize.com/optimize.js
https://www.google.com/recaptcha/api.js
https://maps.google.com/maps/api/js
https://maps.googleapis.com/maps/api/js
https://pagead2.googlesyndication.com/pagead/js
https://platform.twitter.com/widgets.js
https://ajax.googleapis.com/ajax/
https://code.jquery.com/

 

5. Media Settings

SG Optimizer lacks many image optimizations (see full list at the bottom of this section).

Using a plugin to optimize images also uses server resources, as well as disk space when backing up images. You’re better off using Cloudflare Pro or Bunny Optimizer which not only supports more optimizations, but optimize them “on the fly” without using server resources or creating backups. However, these cost money so if it’s not in your budget, use Optimole instead.

FlyingPress/Perfmatters have several other image optimizations like lazy loading background images, preloading above the fold images, replacing YouTube iframes with a preview image, and adding missing image dimensions (none of which are supported by SiteGround Optimizer).

	Imagify	ShortPixel	Optimole	SiteGround CDN	Bunny Optimizer	Mirage/Polish
Compression	✓	✓	✓	✓	✓	✓
WebP	✓	✓	✓	✓	✓	✓
Mobile resizing	x	SP Adaptive Images	✓	x	✓	✓
AVIF support	x	✓	✓	x	x	✓
Serve images from CDN	x	SP Adaptive Images	Cloudfront	Google Cloud	✓	✓
No server use	x	x	x	x	✓	✓
No bloat	x	x	Offloading	x	✓	✓
Price	Free 20MB/mo then $9.99/mo	Free 100 credits/mo then $3.99/mo	Free 5,000 visits/mo then $19.08/mo	$14.99/mo	$9.5/mo or $.03/GB w/ FlyingCDN	Free with Rocket.net

 

I don’t recommend SiteGround Optimizer for optimizing images, but if you want to use it, here are the settings.

• Image Compression: Disable –  only enable when using SiteGround Optimizer for image optimization. PSI tests images at an 85% compression level – so that’s what I recommend.

• Use WebP Images: On – if you’re using an image CDN like Cloudflare + Polish, it doesn’t always serve images in WebP, so I suggest converting them with SiteGround Optimizer, another plugin, or uploading them in WebP manually. SiteGround Optimizer’s default WebP quality is 80% and can be changed by adding the code to your functions.php file.

add_filter( 'sgo_webp_quality', 'webp_quality' );
function webp_quality( $quality ) {
    // Add the value you want to adjust as Webp image quality.
    $quality = 80;

    return $quality;
}

• Lazy Load Media: Off – can’t lazy load backgrounds, replace YouTube iframes with a preview image, and has ongoing compatibility issues. Perfmatters and FlyingPress support both so I recommend using one of those for lazy loading, then disable it here.
• Exclude CSS Classes From Lazy Load – “preload critical images” in FlyingPress & Perfmatters already excludes above the fold images from lazy load automatically for better LCP. But if you’re using SiteGround Optimizer’s lazy load, you’ll need to exclude above the fold images by CSS classes or media types. It also includes a “skip-lazy” class.

• Exclude Media Types From Lazy Load – I’m not really sure why things like iframes, videos, and mobile are excluded from lazy load by default. These should be lazy loaded.

• Maximum Image Width: Off – uploaded images over 2560px will be resized for smaller dimensions. Useful if you have clients who upload huge images and don’t know better. To specify a custom maximum image width, add the code below to your functions.php file.

add_filter( 'sgo_set_max_image_width', 'max_image_width' );
function max_image_width( $max_allowed_width ) {
    // Add the value you want to adjust as max image width.
    $max_allowed_width = 1250;

    return $max_allowed_width;
}

 

6. Speed Test

Instead of SiteGround’s speed test, use these:

• KeyCDN’s Performance Test – measures TTFB in 10 global locations instead of only 1 location in PageSpeed Insights. SpeedVitals also tests TTFB in 40 locations [screenshot].
• WP Hosting Benchmark – measures hosting performance, whether object cache is working, and runs tests related to CPU/memory, filesystem, and database [screenshot].

 

7. SiteGround Optimizer + Perfmatters

Configure SiteGround Optimizer normally except:

• Keep all 3 caching layers on.
• Use 1 plugin to disable emojis.
• Use 1 plugin to control Heartbeat.
• Use 1 plugin to clean your database.
• Use 1 plugin for lazy loading (I recommend Perfmatters).
• Use 1 plugin to defer JavaScript (you can both delay/defer it).
• Use 1 plugin to preload fonts and prefetch to external domains.
• Leave SG’s CSS settings off and use “remove unused CSS” in Perfmatters.

Configure Perfmatters normally while taking advantage of these features:

• General settings (bloat removal, etc).
• Asset settings (script manager, delay JavaScript, remove unused CSS).
• Preloading (instant page, preloading CSS/JS files, preloading critical images).
• Lazy load: images, iframes, add missing dimensions, CSS background images, etc)
• Fonts (add font-display: swap and use local Google Fonts).
• CDN settings should be off unless using something like BunnyCDN.
• Analytics settings should be off since Google Analytics is usually delayed.

 

8. SiteGround Optimizer + FlyingPress

Configure SiteGround Optimizer normally except:

• Disable file-based caching and browser caching.
• Use 1 plugin to disable emojis.
• Use 1 plugin to clean your database.
• Use 1 plugin to minify/defer JavaScript.
• Use 1 plugin for lazy loading (I recommend FlyingPress).
• Keep heartbeat optimization on (FlyingPress doesn’t do it).
• Use 1 plugin to preload fonts.
• Leave SG’s CSS settings off and use FlyingPress’ CSS settings with remove unused CSS.

Configure FlyingPress normally while taking advantage of these features:

• Remove unused CSS.
• Lazy render HTML elements.
• Preload links.
• Delay JavaScript.
• Bloat removal.
• Optimize Google Fonts to host them locally.
• Image optimizations (lazy load, add missing dimensions, preload critical images).
• Lazy load iframes and use placeholder images.

 

9. SiteGround Optimizer + WP Rocket

Configure SiteGround Optimizer normally except:

• Disable file-based caching and browser caching.
• Use 1 plugin to disable emojis.
• Use 1 plugin to control Heartbeat.
• Use 1 plugin to clean your database.
• Use 1 plugin to minify/defer JavaScript.
• Use 1 plugin for lazy loading (I recommend WP Rocket).
• Use 1 plugin to preload fonts and prefetch to external domains.
• Leave SG’s CSS settings off and use WP Rocket’s CSS settings with remove unused CSS.

Configure WP Rocket normally while taking advantage of these features:

• Remove unused CSS.
• Preload links.
• Delay JavaScript.
• Image optimizations (lazy load, add missing dimensions).
• Lazy load iframes.
• Leave cache preloading disabled.

 

10. Cloudflare APO

I recommend Cloudflare’s APO over SiteGround’s CDN.

Regardless of what Hristo says, Cloudflare APO is not the same as SiteGround’s dynamic caching. Cloudflare’s network has 100+ more PoPs than SiteGround’s, so to basically say they’re the same is a lie. They just want you to sign up for their CDN and pay them instead of Cloudflare.

Another reason not to use SiteGround’s CDN is you have to use their DNS to use it. And if you haven’t read about the Google blocking fiasco, SiteGround’s DNS was blocked by Google for 4 days which they blamed on Amazon/Google, but came out with a “fix” just a few days later. All while their client’s Google rankings plummeted or even got completely deindexed from Google.

 

SiteGround Optimizer Isn’t Stable

SiteGround Optimizer constantly runs into compatibility issues with Elementor, Divi, WooCommerce, and other themes/plugins.

Instead of fixing them, they like to push the blame on the themes/plugins. Which also means there’s little to no documentation about known compatibility issues. They also don’t thoroughly test updates before releasing them, making the plugin extremely unstable. There, I warned you.

 

Leave SiteGround, They’re Awful

I originally left SiteGround for Cloudways Vultr High Frequency and posted my results in the WordPress Hosting Facebook Group. But that Facebook Group (along with several others) is now run by SiteGround’s affiliates, so join WP Speed Matters if you want less biased feedback.

Since then, I moved to Rocket.net who is even faster. Unlike SiteGround’s shared plans, Rocket.net and Cloudways Vultr HF are cloud hosting with Cloudflare Enterprise (faster than APO alone), NVMe storage (faster than SATA), Redis (faster than Memcached), and MariaDB (faster than MySQL). And unlike Cloudways, Rocket.net has a lot more resources (32 cores + 128GB RAM) with APO and LiteSpeed’s PHP. In fact, Rocket.net is so fast that they average a <100ms global TTFB which you can test in KeyCDN or SpeedVitals. If yours is slow, you need to rethink your hosting/CDN setup since those are 2 main TTFB factors. Another solid tool to test hosting performance is the WP Hosting Benchmark plugin. TTFB is also 40% of your LCP score.

Maybe you haven’t heard of them because they don’t go aggressive marketing, but here’s an email I got, read this Facebook thread, or see other people who moved from SG to Rocket.net.

Curious to why SiteGround was slower, I made a table.

	SiteGround GrowBig	ChemiCloud WordPress Turbo	NameHero Turbo Cloud	Cloudways Vultr HF (2GB)	Rocket.net Starter Plan
Type	Shared	Shared	Shared	Cloud	Private cloud
Server	Apache + Nginx	LiteSpeed	LiteSpeed	Apache + Nginx	Apache + Nginx
Cores/RAM	Not listed	3 cores/3GB (scalable to 6/6)	3 cores/3GB	1 core/2GB	32 cores/128GB
Storage	20GB SATA	40GB NVMe	Unlimited NVMe	64GB NVMe	10GB NVMe
Object cache	Memcached	Memcached	Redis	Redis Pro	Redis
PHP processor	FastCGI	LiteSpeed	LiteSpeed	FPM	LiteSpeed
PHP workers	CPU limits + suspensions	Resource limits	Resource limits	Unlimited	Unlimited
Database	MySQL	MariaDB	MariaDB	MariaDB	MariaDB
CDN	SiteGround CDN ($14.99/mo)	QUIC.cloud ($.02-.08/GB)	QUIC.cloud ($.02-.08/GB)	$5/mo Cloudflare Enterprise	Free Cloudflare Enterprise
CDN locations	176	80	80	285	285
Full page caching	✓	✓	✓	x	✓
Smart routing	Anycast	Anycast	Anycast	Argo/Tiered Cache	Argo/Tiered Cache
Optimize images	Very limited	QUIC	Mirage/Polish	Mirage/Polish	Mirage/Polish
Mobile image resizing (for LCP)	x	x	x	✓	✓
DNS	Blocked by Google for 4 days	Use QUIC’s DNS	Use QUIC’s DNS	DNS Made Easy (use Cloudflare)	Cloudflare
Cache plugin	SG Optimizer	LiteSpeed Cache	LiteSpeed Cache	Use FlyingPress	Use FlyingPress
Data centers	10	11	US + EU only	44	Served from Cloudflare edge
Bandwidth or monthly visits	100k	Unlimited*	50k	2TB	50GB + 250k
Control panel	Site Tools	cPanel	cPanel	Complex	Easy to learn
Email storage	10GB	Unlimited	Unlimited	x	x
Major incidents	TTFB, DNS, CPU issues (denies it)	None	2011 node outage	None	None
Support	C	B	B	C	A
Migrations	$30/site	10-200 free	1 free	1 free + $25/site	Unlimited free
TrustPilot rating	4.6/5	4.9/5	4.6/5	4.5/5	4.9/5
Monthly price	$3.99 (1 year)	$6.98 (3 years)	$9.98 (3 years)	$30 (monthly)	$25 (1 year)
Renewals	$24.99/mo (1 year)	$19.95/mo (1 year)	$19.95/mo (1 year)	$30/mo	$25/mo

 
If Rocket.net doesn’t work, NameHero Turbo Cloud and ChemiCloud WordPress Turbo are cheaper but use faster LiteSpeed servers with NVMe SSDs + MariaDB. Which means you’ll use LiteSpeed Cache + QUIC.cloud’s CDN (arguably the fastest setup on a budget). Just make sure you use QUIC’s paid plan which unlike the free plan, uses 80 PoPs + DDoS protection with full page caching. All these options are faster than SiteGround, but they’ll obviously never admit it.

Final Thoughts

SiteGround Optimizer can quickly turn into a mess or yield bad results if you only stick to SiteGround products. Don’t think twice about trying Cloudflare APO and other cache plugins.

They help.

Cheers,
Tom