A/B Test Lab: live tests, the planner, the manual log and the one-variable rules
Real title tests running on YouTube, each variant pushed live in turn, and the winner yours to push permanently. What your changes did sits at the top; the planner, the manual log and the history keep every test honest.
Live tests
What your changes did: A/B tests won, kept, unclear or running; straight changes up, down, within 10 percent or still measuring. Below, every live title test with variant A and B and the days left in this half. Start one from Optimise.
Planner, manual log, history, rules
Test Planner drafts a test with a hypothesis and an evaluation window. Manually Logged records a test you ran in Studio. Test History keeps every result. One-Variable Rules says why a test changes one thing at a time, and refuses a test that would not be readable. The Guide at the top carries the two timing rules: start a live test two to three weeks after publish, and a title change makes YouTube re-index the video while a thumbnail change does not.
Why it works this way
A test changes one variable on the same video in back-to-back halves, and its verdict is one of four honest words including no clear difference, so a win is a measured win and not a hope.