FlyingPress is one of our recommended WordPress performance plugins. You can get it at flyingpress.net. We generally recommend either WP Rocket or FlyingPress – broadly speaking, the difference between the two is that FlyingPress is a bit more aggressive in terms of what it can do with optimizations and it can be faster in some circumstances, whereas WP Rocket focuses more on stability and reliability.
In this post, we walk you through the settings we use after optimizing 5,000+ WordPress sites at WP Speed Fix. These are the optimal FlyingPress settings based on what we’ve found works best for speed, reliability, and passing Core Web Vitals.
One thing to keep in mind: we never want to sacrifice reliability for speed. If you have a complex website, a heavy website, or something like a WooCommerce site with a lot of plugins, you need to be mindful that you’re not getting too aggressive with optimization. When you get too aggressive, you tend to break things in ways that aren’t immediately obvious – things like sliders, accordions, or menus can break and maybe only on some devices.
Table of Contents
FlyingPress Settings Video Walkthrough
If you prefer to watch rather than read, here’s our full video walkthrough of every FlyingPress setting:
FlyingPress Dashboard
The Dashboard is pretty standard. You can preload the cache, which builds the pages in advance. Remember, page caching is where all the WordPress pages are built in advance and saved on the server ready to go for when a visitor comes to the site. They can just be served up – all the database lookups, all the PHP processing, everything is done and ready.
If a page is not cached, all that work has to happen on that page load, which can take anywhere from 1 to 10 or even 20 seconds with a heavy site. And if you don’t have caching, that has to be done every single time the page is loaded. So we need caching for WordPress to run fast.
From the Dashboard you can:
- Preload Cache – Goes through the sitemap and loads pages like a regular user, causing the plugin to build and save those pages
- Purge & Preload – Flushes the cache completely and then preloads it fresh
It also tells you the cache status – how many pages are cached in total.
Optimization Tab
There’s a lot of stuff on this page. Let’s go through each section.
CSS & JavaScript Minification – Turn It OFF
We do not use minify at all for CSS or JavaScript. It’s a pointless optimization. Minification makes files a tiny bit smaller by stripping out line spaces and comments, but modern web servers have gzip and brotli compression which is way more powerful and way more effective. Stripping out a few characters here and there does nothing for speed.
Worse, minification can actually break caching. When the plugin creates a minified CSS file, it creates a temporary filename with a random string of characters. Every time you clear the cache, that filename changes. So if you have visitors who’ve been to the site and they come back after you’ve refreshed the cache, that CSS file is no longer the correct file in their browser cache – they have to download it again, making their second visit experience slower.
It can also cause problems with aggressive caching setups. If you’re using page caching and Cloudflare caching, the minified files can cause those caches to mismatch, and you end up with a version of the site pointing to CSS files that no longer exist. So turn off minify for both JavaScript and CSS.
Remove Unused CSS – It Depends
Whether or not this does anything beneficial for speed depends on your theme. If you have a modern theme that’s very lightweight and already optimizing CSS, you might not need this. We had it turned on for this site because the design is a bit heavy.
Be careful not to do the same optimization in two different places. If your theme is optimizing CSS (like GeneratePress does), you don’t want to also use it in FlyingPress. If you layer the same optimization twice, it can break things, make things unreliable, and actually make things slower. The same applies if Cloudflare is doing an optimization – don’t duplicate it in the plugin.
JavaScript Optimization – Be Very Careful
We try to avoid the loading scripts and delaying JavaScript settings. There are a few related options here:
Defer JavaScript – This means scripts don’t fire until the browser has finished downloading everything and started rendering the page. This is generally safe.
Load Third Party Scripts on Interaction / Delay JavaScript – These are the ones to be careful with. They basically pause JavaScript until the user interacts with the site (moves the mouse, clicks, scrolls). This will make your site look a whole lot faster in Google PageSpeed Insights, but if your site relies heavily on JavaScript (like a WooCommerce site), you can actually break the site and make it slower.
How to test if you’ve broken things: Load the site and don’t interact with it. Don’t move the mouse, don’t do anything. If the render is not complete – if it doesn’t show the entire site – then it’s broken something. This can also break SEO: if Google or AI crawlers don’t see a complete version of the site, they may not rank you or you may even get a penalty.
Delaying some scripts like LiveChat is a very good idea because those scripts are heavy and slow. But if you delay the core JavaScript needed to render the site, you can break things very quickly. Check the Console tab in developer tools (right click > Inspect > Console) – any JavaScript errors will show up as red.
Self-Host External CSS and JavaScript – Turn It ON
This is where the site refers to externally hosted copies of JavaScript or CSS (like Google-hosted files). You probably want to host those on the site itself so you can control the caching. We’d say turn this on, but again check the render and the console tab for any issues.
Lazy Loading Images, Videos & Iframes – Turn It ON
Lazy loading means images don’t load until you scroll down to that part of the page. It only loads images above the fold first, then loads the rest as you scroll. This makes the load much faster and lighter. We generally have all of these turned on.
Again, don’t double up. If you’re using lazy loading in your theme, don’t also use it in the plugin.
For YouTube, there are a couple of different lazy load options. The YouTube player is very heavy so we always want to lazy load it. The Lightweight YouTube Previews option just shows a preview thumbnail for the video, and when you click it loads the whole player. That’s the best option, though not all themes and page builders work with it, so just check your site.
Fonts – Turn Them All ON
We generally leave all three font settings on:
- Preload Fonts – Speeds up font loading
- Self-host Google Fonts – Bear in mind that Cloudflare also has this setting, so don’t use it in both places
- Use System Fonts First – A delay/swap setting where it renders the site with system fonts first, then swaps in the custom fonts once loaded
If you have a lot of fonts or a very complicated design, just look at the site and make sure these settings don’t break anything. More common issue on older sites with unusual font setups.
Lazy Rendering – 50/50
This one is a bit of a 50/50. For a simple static page with some images, it’s fine. If you have a complicated design, be careful with it. You don’t necessarily want to lazy render stuff on complex pages.
Like everything on the Optimization tab – a lot of these things depend on the site. Newer themes and builders will be more compatible. Just be mindful.
Images Tab
FlyingPress now has compression and optimization built in. Prior to this, we were using EWWW Image Optimizer, which we still use and is a very good plugin.
If you Google “best WordPress image compression plugin,” you’ll find all these comparisons of which one does the best compression. They’re all going to be roughly within 5% of each other. They all use the same set of algorithms to compress images, so it’s not really a case of which one is better at compressing – they’re all pretty much the same.
We use EWWW Optimizer because it uses server CPU to do compression, which is much faster than plugins that send images to an external API and wait for them to come back. That matters when you have a site with 30,000 images to compress.
For the plugin’s built-in image optimization:
- Image Format – AVIF is a newer format that’s probably better than WebP. The plugin will dynamically create versions of images in WebP or AVIF and serve the optimized version to browsers that support it
- Compression Type – Lossless means no quality loss. If you have an e-commerce site, you probably don’t want lossy. Lossy gives you even smaller files but with some quality loss. For non-product sites where image quality isn’t critical, lossy is fine
- Optimize New Uploads – Yes, turn this on. Just keep in mind it makes the upload process slower
- Exclude Images – If there are images you don’t want optimized, you can exclude them here
Caching Tab
Preload Links on Hover (Just-In-Time Preloading) – This uses instant.page technology. There’s a gap between when you hover on a link and when you click on it – in that gap (which can be several seconds), the browser can actually download the entire next page. So when you click, the page loads almost instantly. Turn this on.
Separate Cache for Mobile and Desktop – You probably don’t need this unless you have a separate mobile site or your page builder serves completely different pages for mobile and desktop.
Cache for Logged-in Users – Turn this on if you have a WooCommerce site, LMS, or membership site with logged-in users. We don’t have logged-in users on our site, so we leave it off.
Auto-Refresh Cache – We recommend turning this on. It clears the cache and rolls it over periodically. This is useful because if for some reason a page is broken or the render is broken, this will flush it out and rebuild those pages.
The advanced caching settings (exclude pages, query string caching, cookies) are more advanced – if you’re poking around in there, you’ll know what those settings are for.
CDN Tab
There are lots of different CDN options inside FlyingPress. We just use the Cloudflare integration. We don’t use custom CDN, and we don’t use the FlyingCDN service.
We would recommend that you use a direct Cloudflare account rather than FlyingCDN or any other integration with a cloud provider. You’ll get a better result using your own Cloudflare account, and you’ll also be able to use things like the firewall and tweak a lot of settings useful for SEO.
Enable Page Caching – This is a great feature. It replicates Cloudflare’s APO service (which costs $5/month) natively through the plugin at no extra cost. It caches your pages on the Cloudflare network, making them even faster. So there’s a $5/month saving right there if you have a simple site and don’t need the full APO service.
Database Tab – Leave It All OFF
There really isn’t much to do here. This idea of “cleaning your database” is just nonsense – it’s not like cleaning your teeth. You shouldn’t need to use any of this stuff. Database cleaning doesn’t do anything for speed.
If you have a really old site and you’ve installed the plugin for the first time, there might be some transients that need clearing out. But broadly speaking, if your database is dirty and full of stuff, you’ve probably got a bigger issue that you shouldn’t be DIYing in the first place.
We just leave all this stuff off.
Bloat Tab – We Don’t Recommend It
We don’t like to mess with this too much because it can break things, and most of this stuff doesn’t make anything faster. You’ll see this recommended around the web, but it’s largely a nonsense optimization.
For example, limiting revisions – why would you do that? It doesn’t make any difference for speed. It doesn’t matter from a speed perspective whether there are three revisions or ten revisions saved. It saves space in the database, but that’s not really going to impact speed unless it’s an extreme scenario.
We wouldn’t recommend using any of these settings by default unless there are particular reasons, and more often than not, you break things by turning this stuff on rather than make anything faster.
Settings Tab
The Settings tab has license management, Core Web Vitals tracking, and import/export configuration.
We don’t use the Core Web Vitals tracking here. You can turn it on for some basic tracking, but we use our own Core Web Vitals tracker tool which is much more precise and granular.
How To Test If You’re Breaking Things
An easy way to test if any settings are causing issues is to use the Console tab in Chrome Developer Tools. Right-click on the page, click Inspect, then click the Console tab. Any errors that come with a page load will show up here in red. Each page load will have its own set of warnings and errors, so you can quickly see if something is going wrong.
A few things to keep in mind:
- Reliability over speed – When in doubt, use the more conservative settings
- Don’t double up optimizations – If your theme, Cloudflare, or another plugin is already doing an optimization, don’t duplicate it in FlyingPress
- Check the Console tab – Use Chrome DevTools to check for errors after changing settings
- Test without interacting – When testing JavaScript delay settings, load the site without moving the mouse or clicking anything to see if the full page renders
If you need help with your site, head over to wpspeedfix.com. We’re a specialist site speed optimization and technical agency. You can request a free audit from our homepage. We also have a bunch of free tools – no opt-in required – including a free SEO audit, free Core Web Vitals report, and free WordPress speed test.