Custom percentage splits for control and target groups

I’d love to suggest an improvement to how splits work in workflows and experiments.

Currently, splits are limited to a random 50/50 distribution. For many use cases—especially when working with control and target groups—this is quite restrictive. It would be extremely valuable to be able to define custom split percentages (e.g. 90/10, 80/20, 70/30).

This would allow teams to:

  • Maintain a smaller control group while exposing most users to the new experience
  • Run more statistically sound experiments without sacrificing performance
  • Gradually roll out changes while still measuring impact against a control
  • Align experiments with business risk tolerance

Being able to customize split percentages would significantly improve HubSpot’s experimentation and optimization capabilities and make control/target group testing much more practical in real-world scenarios.

Thanks for considering this idea, and for continuing to improve the platform.

Best regards,
Louise