UXtweak runs the tests. Intervool synthesizes what people said.

UXtweak is a broad UX research platform for moderated and unmoderated usability testing, card sorting, tree testing, surveys, and participant recruiting, with a usable free plan. It's built to evaluate designs. Intervool solves a different problem: turning user interviews and post-test debriefs into evidence-linked themes, personas, and a prioritized roadmap. If you need to test whether users can complete a flow, use UXtweak. If you need to make sense of what users told you across dozens of conversations and carry it into product decisions, use Intervool — and bring the UXtweak sessions along.