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A/B TestingOctober 14, 2025·Koryla Team·1 min read

What is A/B Testing and Why Does It Matter?

A/B testing lets you compare two versions of a page to see which one performs better. Here's why every product team should be running experiments.

A/B testing (also called split testing) is one of the most powerful tools in a product team's arsenal. Instead of guessing which version of a page or feature will perform better, you let real users decide.

How it works

You split your traffic into two groups:

  • Group A sees the original version (the control)
  • Group B sees the new version (the variant)

After enough data is collected, you can see which version drives more conversions, signups, or whatever metric you care about.

Why edge-based testing is different

Traditional A/B testing tools inject JavaScript on the page, which causes a flash of unstyled content (FOUC) — users briefly see the original before the variant loads. It's jarring and hurts your results.

Koryla runs experiments at the edge — inside your framework's middleware layer, before the page reaches the browser. Whether you're using Next.js, Astro on Netlify, or a WordPress site, the variant is assigned server-side. There's no flicker, no layout shift, no performance penalty.

Getting started

  1. Create an experiment in your Koryla dashboard
  2. Add the Koryla middleware to your project (Next.js, Netlify, or WordPress)
  3. Define your variants and their target URLs
  4. Start collecting data

No script tags, no client-side JavaScript, no developer bottleneck for every experiment. The middleware handles everything before the browser sees a single byte of HTML.

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