A/B Testing Tools & Software

The A/B testing tools market is approaching $1 billion and growing at about 14% per year. Yet only 11.5% of the top million websites actually run a testing tool. That’s a lot of sites leaving money on the table.

The market itself is lopsided. Most tools were built for enterprise teams with dedicated optimization specialists and six-figure budgets. If you’re a marketer or founder at a smaller company, the options look expensive and complicated. They don’t have to be.

When Google Optimize shut down in September 2023, an estimated 2-3 million websites lost the only simple, free testing tool that worked inside their Google stack. That gap still hasn’t been properly filled. Enterprise tools are too expensive. Developer tools assume you write code.

Kirro was built for that gap. EUR 99/month, unlimited tests, unlimited visitors, visual editor, GA4 integration. No per-visitor pricing that punishes you for growing. Try it free for 30 days.

How to pick the right tool

A/B testing tools fall into four categories. Knowing which one fits saves you from buying a race car when you need a bicycle.

Visual editor tools are the starting point for most small teams. You click on a headline, change it, and hit start. Kirro fits here. So does VWO’s basic plan and Crazy Egg.

Full-stack platforms bundle everything: visual editor, server-side tests, personalization, heatmaps, session recordings. VWO and Optimizely live here. You pay for the bundle whether you use all of it or not.

Developer-first tools are free or cheap but need someone who can write code. GrowthBook is open source and genuinely free. PostHog and Statsig have generous free tiers. If you have a developer on the team and a data warehouse, these are worth a look. If you don’t, skip them.

Pricing models matter too. Some tools charge per seat (per person who logs in). Others charge per MTU (monthly tested users, meaning visitors who see a test). MTU pricing means your bill goes up as your traffic grows. Seat pricing stays flat. Kirro charges a flat EUR 99/month regardless of traffic or team size. That’s unusual. Most tools in this space charge more as you grow.

One thing every “best tools” roundup skips: only about 1 in 8 A/B tests produce a clear winner. The tool you pick matters less than actually running tests consistently. A EUR 99/month tool used weekly beats a $36,000/year tool used quarterly.

Find the right guide for your question

Each of these posts goes deep on a specific angle. Here’s where to start based on what you’re looking for.

Want a full buyer’s guide? Our A/B testing software comparison reviews 13 tools side by side. Total cost of ownership, real pricing (not just the sticker), and tradeoffs nobody else mentions. It’s the deep dive.

Short on time? The best A/B testing tools post is the 5-minute version. Five picks organized by use case: best for small teams, best for enterprise, best for ecommerce, best for developers. Clear winner recommendation upfront.

Need redirect testing? Split testing (sending visitors to completely different URLs) is a different job than element-level A/B testing. Our split testing software guide covers 8 tools that handle real URL redirects and explains when you need that instead of standard A/B testing.

Building a mobile app? Mobile testing has unique headaches: app store review delays, version fragmentation, and smaller sample sizes. The mobile app A/B testing guide covers the best tools and what makes mobile different from web testing.

The bigger picture

A/B testing tools are one piece of the conversion puzzle. The full CRO stack includes heatmaps, session recordings, surveys, and analytics alongside testing. Our CRO tools guide breaks down the full toolkit.

For the fundamentals of A/B testing itself (how it works, what to test first, how to read results), start with our A/B testing pillar guide. Everything in this section lives under that umbrella.