Use this form to compare two versions of an AdWords ad, sales page, etc., and discover whether the difference between their click-through or conversion rates is more likely caused by random chance, or a real difference that will continue in the long run.
Enter the number of impressions of each version (the number of times it was viewed), and the number of the desired actions that were taken (clicks, sales, signups for a mailing list, etc.). Then click "Compare" to instantly see exactly how confident you can be that the difference between them is real.