← SkillSafe / SEO Split Test
Free · runs on your device

Did your SEO change work?

Give it daily clicks for the pages you changed and for similar pages you left alone. It works out what the changed pages would have done without the change, then tells you the lift, how sure it is, and whether to keep waiting.

Try an example:

1 Your data

Drop a CSV here or click to choose. One row per day with test and control columns, or one row per day per group.
Or paste the data

How it works

  1. Learn the relationship. Before the change, it fits how the test pages track the control pages day by day, with a weekday pattern and day-to-day carry-over in the errors. The fit starts from the assumption that both groups move in proportion and lets the data adjust it.
  2. Forecast the counterfactual. After the change it uses the control pages to forecast what the test pages would have done if nothing had changed, 1,000 times with the uncertainty included.
  3. Compare. Actual minus expected, day by day and in total, gives the lift and its 95% interval. The share of forecasts below the actual total is the chance the effect is positive.
  4. Check itself. A difference-in-differences comparison and placebo runs at fake dates show whether the result holds up.

Pick control pages that are similar to the test pages and were not changed. A sitewide update, a seasonal spike or a migration that hits only one group will look like an effect.