Optimizely Web Experimentation

Optimizely is one of the older names in website testing. Its web experimentation product lets a team change a page in a visual editor or with code, split traffic between versions, and read the results through its own statistics engine, which is built so you can watch results as they come in without the usual early-peeking problems.

Large retailers and brands use it to test headlines, layouts, product page modules and checkout steps. Feature experimentation, a separate product, moves testing into the code itself, which suits teams that want to test search ranking, pricing logic or app features as well as page design.

Before you buy, check how much traffic you have. Tests on low-traffic pages take a long time to reach a clear answer on any tool. Also ask which parts of the suite your contract includes, since content management, personalization and testing are sold as separate pieces.