We've run A/B tests for years across e-commerce, SaaS, and content sites. The tools were always the same: powerful enough, but with pricing designed to scale against you. Hit 100K visitors? Time to upgrade. Cross 500K? Another tier. Run a successful campaign that drives traffic? Congratulations — here's a bigger invoice. The industry calls this “MTU-based pricing” (Monthly Tested Users), and it means the better your site performs, the more you pay for the exact same tests. We built Otter A/B on a different principle: charge for projects, not visitors. Every plan includes unlimited tests, unlimited visitors, and the full feature set. The only difference between plans is how many projects you can run. The result is a testing platform where you can focus on learning what works, without watching a usage meter or worrying about overage charges at the end of the month.

Otter A/B

Behavioural Intelligence

Behavioural Intelligence