A/B test tools compared: Varify, VWO and Optimizely

Conclusion: where do you start?

Don't have a large testing budget yet? Start with Varify. It's a mature tool for visual testing and personalisation, with the most competitive price point of the tools in this overview. You can build variants, measure goals and read results straight away — without being locked into a four-figure-a-month annual contract.

Do you have a lot of traffic, multiple teams and a need for server-side testing, feature flags and extensive governance? Then VWO and Optimizely are the logical candidates.

Why so many people have been looking since Google Optimize

Google Optimize was, for years, the free standard for anyone wanting to start A/B testing without paying anything: free, directly linked to Google Analytics, and good enough for most websites. When Google shut down that tool at the end of September 2023, the free entry point disappeared overnight. Thousands of businesses — from online stores to B2B sites — had to look for an alternative, and found that the commercial tools are often considerably more expensive.

That's still the main question we get: which tool fits us, without immediately costing us hundreds of euros a month? So below we line up the three tools we come across most in practice.

Varify

A German tool focused on visual testing: you build variants in an editor on top of your own site, without needing a developer. Besides classic A/B tests, you can run split-URL tests, personalise, and set up custom goals.

Advantages

• Best price-to-feature ratio of this line-up: you get the features you'll actually use for 90% of your tests, for a fraction of the price of the enterprise tools.
• Fast start: place the script, set your goals, and your first test can go live the same day.
• A visual editor that also works fine for marketers without frontend knowledge.
• Integrations with GA4 and other analytics tools, so you keep your existing reporting.
• Friendly, personal support — you get an actual person on the line.

Disadvantages

• A smaller player than VWO and Optimizely: less ecosystem, fewer integrations, fewer standalone modules.
• Server-side testing and feature flags aren't its strongest point; for complex application testing, look elsewhere.
• Less extensive governance (roles, permissions, audit trails) than enterprise suites.

For: small and medium businesses, online stores, marketing teams and freelancers who want to test seriously without an enterprise budget. Try the tool via this link.

VWO

A mature platform (Visual Website Optimizer) that combines testing, heatmaps, session recordings, surveys and a feature-flag module.

Advantages

• All-in-one: quantitative testing and qualitative research in the same environment.
• Strong statistics (Bayesian) and good reporting for stakeholders.
• Both client-side and server-side testing possible.
• Extensive documentation and many integrations.

Disadvantages

• Price rises quickly as you add more visitors or modules.
• More tool than the average website needs; you pay for features that sit idle.
• Requires someone who actually manages the platform, or it stays at a handful of tests.

For: organisations with a lot of traffic, a steady CRO rhythm and budget for a platform. More info at VWO.

Optimizely

The best-known name in experimentation, now grown into a broad digital experience platform with CMS, content marketing and personalisation.

Advantages

• Very strong in server-side experiments and feature flags — popular with product teams and developers.
• Scales to large numbers of tests, teams and markets.
• Extensive permissions, workflows and reporting.

Disadvantages

• Clearly the most expensive of this line-up; pricing is on request and typically starts in the enterprise segment.
• Implementation and management require technical capacity.
• Overkill for a site with a few thousand visitors a month.

For: enterprise organisations with their own product and development teams. More info at Optimizely.

What about Google Optimize?

Google Optimize no longer exists. Google itself points to partners for experimentation, and to experiments within Google Ads and similar environments for specific purposes. What you do keep: GA4 as your measurement layer. You can connect all the tools above to GA4, so your test results show up in your existing reporting.

What to pay attention to when choosing

• Number of visitors. Pricing is almost always based on visitors or tested traffic. Plan ahead for a year of growth.
• Client-side or server-side. Visual testing on a marketing site is a different job from experimenting inside an application or checkout.
• Who builds the variants? Without a developer on board, a good visual editor is the difference between testing and not testing.
• Measurability. Are your goals (purchase, lead, funnel step) already set up properly? Without reliable measurement, any tool is worthless.
• Volume per test. With few conversions a month, significance takes a long time. Test bigger changes then, not button colours.

How we approach it

We start by looking at your numbers: how many visitors and conversions do you have, and which step in the funnel leaks the most? Then we choose the tool that fits — often Varify for small and medium businesses and online stores, VWO or Optimizely when there's real volume and technical capacity behind it. We set up the measurement, build the first tests, and teach your team how to keep testing themselves. Want to take it over afterwards? Great — that's exactly the point.