Your site feels sluggish or PageSpeed Insights is showing red, and you have no idea what’s causing it. A slow WordPress website is usually caused by cheap shared hosting, missing caching, uncompressed images, too many or resource-intensive plugins, an outdated PHP version, a cluttered database, external scripts, and a resource-intensive theme or page builder. Below, you’ll find information on how to identify each cause and how to check for it. The order in which you should address these issues is listed in How to Speed Up WordPress: The Complete Guide.
Measure first, then search
First, figure out where the bottleneck is, because without measuring it, you’re just guessing. A doctor wouldn’t prescribe medication without a diagnosis, and installing a caching plugin on an overloaded server is like taking acetaminophen for a broken leg. I always test using PageSpeed Insights or GTmetrix, on both mobile and desktop, and several times in a row, because a single measurement doesn’t tell you much. Do this while logged out in an incognito window, because your own browser and your logged-in session skew the results. Also, test more than just the homepage. A product page or the checkout page often behaves very differently.
Three metrics tell you the most. TTFB (time to first byte) is the time it takes for the server to send back the first byte, and for a healthy site, this is less than 0.8 seconds. LCP measures when the largest visible element appears on the screen, and Total Blocking Time (TBT) measures how long scripts block the page. A PageSpeed score of 90 to 100 is good, and 50 to 89 could be better, but it’s still just a lab test. What Google counts are the Core Web Vitals for real visitors, with an LCP within 2.5 seconds. With those three values in hand, use this table to find the track.
| What You See | Probable cause |
|---|---|
| High TTFB on all pages | Hosting or No Caching |
| Slow LCP, large image at the top | Images |
| High Total Blocking Time | External scripts, plugins, or themes |
| Slow dashboard, fast front end | Database, plugins, or server resources |
| Slow only when it's busy | Insufficient server resources |
| Only the shopping cart and checkout are slow | Pages without a cache, see Slow WooCommerce online store |
| It's been running slowly since yesterday | Update, bots, malware, or system failure |
Server-side causes
Slow performance can be caused by issues on the server side or the front end, and you can identify server-side issues by a high TTFB. The first suspect is cheap shared hosting. If there are too many sites on a single server, yours will have to wait its turn, especially during peak traffic. If the TTFB is high even on a cached page, it’s almost certainly due to the hosting. In that case, choose hosting optimized for WordPress, such as Managed WordPress Hosting, or for an online store Managed WooCommerce Hosting. See also What Makes Up Fast WordPress Hosting. A CDN is especially helpful for visitors from far away, since for traffic from the Netherlands, a server in Europe is already close by.
Without caching, the server rebuilds each page from scratch for every visitor. You can tell from the response headers whether there was a cache hit. A common mistake I see is when two caching plugins interfere with each other. See Caching in WordPress. An outdated PHP version is the third one, because each new version processes the same code faster. You can see your version under Gereedschap > Sitediagnose > Info > Server. Test an upgrade first and follow Update PHP Version. Then the database. Revisions, transients, and autoload options from old plugins in wp_options slow down every database query. Site Diagnosis issues a warning if there is a large amount of autoload data. Make a backup, and then clean up the database.
Most of what we handle as standard at Surver is on this side. All shared hosting plans run on LiteSpeed servers with NVMe storage and LiteSpeed Cache; OPcache is always enabled; and each account is isolated from neighboring accounts using CloudLinux and CageFS. You can change your PHP version yourself via cPanel > Select PHP Version, from 7.4 through 8.5. To find out whether your site is reaching the CPU or memory limits of your plan, please contact support.
Root causes
On the front end, you’ll see the delay reflected in a slow LCP or a high TBT, even though the server itself responds quickly. It usually starts with images. A single photo of a few megabytes at the top of the page can single-handedly determine your LCP, and PageSpeed Insights simply identifies it as the LCP element. Resize, compress, and convert to WebP; see Optimize images. By the way, you don't upload a video yourself; you embed it via YouTube or Vimeo.
When it comes to plugins, the type matters more than the number. A single heavy plugin that loads scripts on every page slows things down more than ten lightweight ones. Query Monitor shows which plugin takes the most time. If you want to disable plugins without visitors noticing, use Health Check & Troubleshooting or a staging environment, which you can do on Surver by cloning your installation in Installatron. Outdated plugins and themes are often slower as well, so Clean up outdated plugins It's part of the deal. If you don't want to keep track of that yourself, it falls under WordPress maintenance.
External scripts are the silent speed killers. Take a Meta Pixel or a Hotjar script, for example—it loads from a different server and blocks the page while it’s loading, which shows up as render-blocking JavaScript and a high TBT. In PageSpeed Insights, under “Third-Party Resources,” you can see exactly what’s being loaded. My advice is to remove anything that doesn’t add value and load the rest via Google Tag Manager only after cookie consent is granted. A heavy theme or page builder creates a lot of extra HTML elements, which PageSpeed flags as an excessive DOM size. Temporarily switch to a default theme on your staging environment to compare, and read Page Builder or Block Editor.
Is the dashboard slow, or did it suddenly start running slowly?
If only your dashboard is slow, it’s almost never because of your images, since the front end is served from the cache and the dashboard never is. That’s where you’ll immediately notice the impact of heavy plugins, extensive autoload options, and insufficient PHP memory or PHP workers. The Heartbeat API and background tasks via WP-Cron—such as a backup or import that’s currently running—can also slow down the dashboard. Query Monitor shows you where the time is being spent here as well. You can adjust PHP settings in Surver via cPanel > Select PHP Version > Options. If a value cannot be set higher, please contact support.
If your site has suddenly become slow, check to see what has changed recently. These are the things I check first.
- A plugin or theme that has just been updated.
- Bot traffic or login attacks. A server-level firewall blocks a lot of traffic, and at Surver, Bot Blocker, automatic IP blocking, and a CAPTCHA after more than ten failed login attempts are the most effective at stopping it.
- Malware that slows down your server. Read Remove malware or outsource the repair through WordPress hacked.
- A problem with your hosting (for Surver, check status.surver.nl) or full storage space.
If these steps don't solve the problem, we'll help you find the cause by WordPress Speed Optimization. If you want to continue on your own, start with the steps in the complete guide.
Frequently Asked Questions
Is it because of my hosting?
If the TTFB remains above 0.8 seconds even on cached pages, then probably yes. If the TTFB is low but the page is still slow, the problem lies on the front end. If the TTFB spikes significantly, especially during peak traffic, your hosting plan is likely running out of resources.
How fast should a WordPress website load?
The Largest Contentful Paint (LCP) must appear on screen for real visitors within 2.5 seconds. The PageSpeed score is a lab test and is primarily intended to provide guidance.
Can Surver figure out why my site is slow?
Yes. Surver analyzes your site, identifies the cause, and resolves it through speed optimization.
