Is there an open-source alternative to VWO for Rails?

Yes — Field Test and Split. Both mount into an application you already run, so there is no second deployment and no second database.

How do I replace VWO in a Rails app?

Add field_test to your Gemfile, mount it in config/routes.rb at /field_test, and run its migrations. The whole integration is two lines and a migration.

How much does replacing VWO save?

VWO is priced from $199/mo. The engines here are open source, so the cost becomes the time to mount one and the resources it uses inside your existing application.

Replace VWO

Split traffic between variants and measure conversion, through a script tag and a hosted dashboard.

VWO website From $199/mo Experiments

Why teams move off VWO

From $199 a month to split traffic and count conversions, through a script tag that cannot see the account a visitor became.

What you give up

The visual editor for building variants without a deploy.

This directory says so when an engine only covers part of the job. A replacement that needs a caveat is still worth knowing about — it just should not surprise you in week three.

Drop-in replacement

VWO → field_test

# Gemfile
gem "field_test"

# config/routes.rb
mount FieldTest::Engine, at: "/field_test"

Read about Field Test →

2 Rails engines that replace VWO

Questions

Is there an open-source alternative to VWO for Rails?: Yes — Field Test and Split. Both mount into an application you already run, so there is no second deployment and no second database.
What do I give up by replacing VWO?: The visual editor for building variants without a deploy.
How do I replace VWO in a Rails app?: Add field_test to your Gemfile, mount it in config/routes.rb at /field_test, and run its migrations. The whole integration is two lines and a migration.
How much does replacing VWO save?: VWO is priced from $199/mo. The engines here are open source, so the cost becomes the time to mount one and the resources it uses inside your existing application.