Best Free A/B Testing Tools in 2026

Amplitude is a digital analytics platform that helps teams understand user behavior with product analytics, session replay, feature flags, and A/B experimentation capabilities.

Mixpanel is a product analytics platform for tracking user interactions. Event-based analytics show how users engage with features. Funnels and flows visualize user journeys. Retention analysis measures long-term engagement. A/B testing and messaging drive growth. The analytics platform product teams use to make decisions.

Flagsmith is an open-source feature flag and remote configuration service for web, mobile, and server-side applications. It lets teams toggle features on or off without redeploying, roll out changes to specific user segments or percentages, and run multivariate A/B tests with analytics integrations. Flagsmith tracks every flag change in an audit log for easy rollback and supports user trait storage for targeting. Deployment options include SaaS cloud across eight regions, private cloud in your own infrastructure, on-premises with Kubernetes or OpenShift, or fully self-hosted from the open-source repository. SDKs cover React, Node, Python, Go, Ruby, .NET, iOS, Android, Flutter, Rust, PHP, and a REST API.

Dub is the open-source link management platform for modern marketing teams. Create short links with advanced analytics, custom domains, A/B testing, and conversion tracking.

Hotjar shows how visitors actually use your website. Heatmaps visualize where users click, move, and scroll. Session recordings replay individual visits. Surveys and feedback widgets collect user opinions. Funnels identify where users drop off. See your site through your users' eyes.

GrowthBook is a warehouse-native feature flagging and experimentation platform used by over 2,700 companies. It connects directly to your data warehouse — Snowflake, BigQuery, Redshift, or others — so experiment results are computed on your own data without exporting events to a third party. The platform includes both Bayesian and Frequentist statistical engines with support for CUPED, sequential testing, and multiple metric corrections. Feature flags evaluate locally via lightweight SDKs (the JavaScript SDK is 9KB) with zero network requests at runtime. A visual A/B test editor enables no-code experiments for marketing and product teams. GrowthBook is available as open-source self-hosted, cloud-managed, or with a managed warehouse option.

Statsig provides feature flags with statistical rigor. Experimentation infrastructure—flags that measure impact properly. The statistics are rigorous. The infrastructure scales. The measurement is built in. Teams wanting data-driven feature management use Statsig for statistical feature flags.

Crazy Egg is a website optimization tool that helps businesses understand how users interact with their websites. It offers a suite of features including Heatmaps, Session Recordings, Surveys, A/B Testing, and Web Analytics to visualize user behavior, identify friction points, and test improvements. This platform is ideal for marketers, product managers, web developers, and anyone looking to improve their website's user experience and conversion rates. By providing insights into what visitors are doing on a site, Crazy Egg enables users to make data-driven decisions to enhance content, design, and overall performance. It aims to make the web more usable by helping businesses optimize their online presence. Key benefits include easy setup with a single piece of code or popular integrations, unlimited team members and domains across all plans, and AI-powered analysis for deeper insights. It helps users identify areas for improvement, test new ideas, and ultimately drive more conversions.

Countly is a product analytics platform for web, mobile, desktop, and IoT with self-hosted and cloud options. Features user analytics, retention, funnels, push notifications, and A/B testing.

Reform is a conversion-focused form builder designed to maximize lead quality and quantity. Unlike traditional form tools, it combines no-code visual customization with advanced features like abandoned submission capture, A/B testing, and real-time email validation. Reform offers flexible layouts beyond single-question-per-page, integrates with major CRMs and marketing tools, and provides both developer-friendly APIs and headless embedding options.

Popupsmart is a no-code popup builder that lets businesses create conversion-focused campaigns in minutes. It uses behavioral targeting, exit-intent triggers, AI-powered design, and A/B testing to capture emails, recover abandoned carts, and promote offers. With 500+ templates, 120+ integrations, and lightweight code that won't slow your site, it serves 20,000+ websites including Greenpeace and UNICEF.

FeatBit is an open-source feature flag and toggle management platform designed to help development teams ship faster, deploy safely, and conduct real-time experiments. It provides the infrastructure for managing feature rollouts, A/B testing, and targeted feature delivery, allowing businesses to validate new features quickly and control their release to specific user segments. The platform emphasizes data privacy and security through its self-hosted deployment options, ensuring data remains within the user's infrastructure. FeatBit is ideal for development teams, product managers, and enterprises looking for a cost-effective yet powerful solution for feature management, especially those building AI agents and software. It supports various programming languages and integrates with modern AI tools, enabling developers to incorporate feature flags seamlessly into their workflows. With options for Docker, Kubernetes, and cloud deployments, FeatBit caters to different operational needs, from development and testing to production-grade environments. The platform's core value proposition includes significant cost savings compared to traditional solutions, full transparency with its open-source nature, and complete control over data and infrastructure. It offers unlimited seats, service connections, and monthly active users (MAU) in its self-hosted free and enterprise versions, providing predictable pricing without escalating costs as teams scale.

Splitbee was a privacy-friendly web analytics tool that offered event tracking, user journey analysis, and A/B testing with a clean, minimal interface. Founded by Tobi and Timo, it was acquired by Vercel and has since been sunset. Former users are directed to Vercel Analytics as the official successor. The product emphasized simplicity, real-time dashboards, and developer-friendly integrations without requiring cookie banners or complex setup.

GO Feature Flag is an open-source feature flagging solution designed to help development teams modify system behavior without changing code. It enables organizations to decouple deployment from release, allowing for progressive feature rollouts, A/B testing, and targeted user experiences. The tool focuses on simplicity, offering a lightweight setup and integration with existing development workflows. This solution is ideal for developers, product managers, and businesses looking to accelerate innovation, reduce deployment risks, and gain insights into feature usage. By providing advanced rollout capabilities and supporting various data storage and notification systems, GO Feature Flag empowers teams to test in production, empower stakeholders, and continuously improve their software delivery process. It embraces open standards through OpenFeature, ensuring vendor neutrality and broad language support.

Superwall is a comprehensive platform designed for mobile app developers and growth teams to build, deploy, and optimize paywalls without writing code. It provides an intuitive drag-and-drop paywall editor, allowing users to create native-feeling monetization screens that perfectly match their brand. The platform supports advanced targeting based on user behavior and demographics, enabling personalized paywall experiences. Beyond design, Superwall offers robust A/B testing capabilities to experiment with different paywall variations and track their performance. It integrates with open-source SDKs for iOS, Android, React Native, and Flutter, making implementation straightforward. The platform also includes unified subscriber management, real-time revenue tracking, and access to a gallery of over 200 proven paywall templates to accelerate launch and improve conversion rates. It empowers non-technical teams to iterate on monetization strategies quickly, reducing reliance on engineering resources.