Best 2 Tools for A/B Test Running in 2026
Last Updated: September 23, 2025
Deciding between two versions of a feature or page is more reliable when tested with real users than guessed at. A/B Test Running tools split traffic between variations and measure which one performs better.
Product and growth teams use A/B testing to make decisions based on actual user behavior.
GrowthBook
GrowthBookOpen Source A/B Testing Platform and 
Amplitude
AmplitudeProduct Analytics Platform for Growth are the best for A/B Test Running. So, let’s take a closer look at both tools.
GrowthBook is an open-source feature flagging and A/B testing platform designed to help companies release features safely and measure their impact with confidence. Think of it as your complete experimentation toolkit that works with your existing data setup.
The platform combines two essential capabilities: feature flags that let you control who sees new features and when, and A/B testing tools that help you understand which changes actually improve your product. What makes GrowthBook special is its warehouse-native approach - it connects directly to your data sources like BigQuery, Snowflake, or Google Analytics instead of requiring you to send data elsewhere.
Founded in 2021, GrowthBook has grown rapidly and now powers experiments at thousands of companies. You can use it as a hosted cloud service or install it on your own servers for complete control and privacy.
Amplitude is a product analytics platform that tracks user behavior through events and interactions. Unlike traditional web analytics that focus on page views, Amplitude captures specific actions like button clicks, feature usage, and user flows to create detailed user journey maps.
The platform helps businesses answer critical questions like "Which features drive retention?" and "Where do users drop off in our funnel?" It provides real-time insights through advanced segmentation, cohort analysis, and behavioral tracking that help teams optimize their products and improve user experience.
Amplitude offers multiple pricing tiers from a free Starter plan to Enterprise solutions. The platform integrates with popular tools and provides features like A/B testing, user segmentation, and predictive analytics. It's trusted by product managers, growth teams, and data analysts who need to make informed decisions based on actual user behavior rather than guesswork.