Will AB Split Test slow down my site?
No. AB Split Test is built to have no measurable impact on page load speed. Here is why.
All variations are pre-rendered in the page HTML
AB Split Test does not make additional server requests to load variations. All test variations are already in the page HTML when it is served. A small JavaScript snippet runs client-side to show the correct variation to each visitor.
This means your server handles no extra load from running a test, and your pages load exactly as fast as they always have.
Tracking uses a lightweight first-party endpoint
When a visit or conversion is recorded, AB Split Test sends a small beacon to a lightweight first-party endpoint on your own server. As of v2.6.0 this endpoint uses a queue, so beacons fire faster and high volumes of concurrent visitors cannot cause dropped or duplicate events.
No data is sent to external servers. No third-party scripts are loaded.
No external scripts, no remote cookies
Most SaaS testing tools load scripts from their own servers, which adds external requests and can affect your Core Web Vitals scores. AB Split Test loads nothing from outside your domain. Everything runs locally.
Compatible with all caching setups
Because variations are pre-rendered in the HTML, caching does not break tests. You can run WP Rocket, LiteSpeed, NitroPack, Cloudflare, or any other cache without variation delivery being affected.
The one thing to watch: if your optimization plugin delays or defers JavaScript, AB Split Test needs to be excluded from that delay. Most major optimization tools are handled automatically. More on JavaScript delay →
High traffic sites
AB Split Test is used on high traffic WordPress sites without performance issues. Test logic runs client-side, database writes are minimal and queued, and there are no per-request server computations beyond standard WordPress page serving.
AB Split Test on high traffic websites →
If you notice a performance issue you think is related to the plugin, contact support. Include your hosting environment and which optimization plugins you are running and we will investigate.