ABalytics.js is a pure javascript library allows you to do simple A/B testing working only on your client-side code. All data is registered as custom variables in your website Google Analytics profile, so you don’t need to configure anything server side.

You simply mark the html elements you want to test on with a class, the substitution is automatic. There is no need to set anything up server side, the data is stored on Google Analytics. You can conduct multiple, independent experiments at the same time. Each experiment will use a custom variable slot. It is pure javascript, you just need to include GA.

Requirements: JavaScript, Google Analytics
Demo: https://github.com/danmaz74/ABalytics
License: MIT License