A/B Testing & Experimentation platforms enable marketing, growth, and CRO teams to run structured experiments on web pages, email content, popups, and on-site experiences — testing creative variants, layout changes, copy alternatives, and conversion-rate-optimization (CRO) ideas to measure causal impact on conversion, engagement, or revenue. Core capabilities include split-test and multivariate test design, client-side and server-side experimentation, statistical-significance and sequential-testing engines, audience targeting (segments, geography, device), result analysis with confidence intervals, and integration with web analytics and CDPs. The market spans web-CRO-flavored platforms (Optimizely Web, VWO, AB Tasty, Convert, Kameleoon) and Adobe Target.