Check enough metrics and one wins by luck. Peek daily and stop on a good day. Slice by segment until something shines. You can make almost any test look like a winner. These tools protect the internal validity of your experiments, so that when you call something a win, you can defend it in any room.
Most ecommerce A/B testing is governance theatre. Teams pick their metric after seeing the results, peek at significance daily, and ship winners produced by platforms nobody ever bothered to calibrate. The math was never the problem.
Each tool here guards a different failure point. The Validator checks whether your testing platform is telling you the truth. Lockbox locks your hypothesis in before any data exists. Reality Check deflates inflated winners before you announce them, and the Ledger asks the uncomfortable year-end question: did any of it actually show up in revenue?
Everything runs in your browser. There are no accounts and nothing gets sent to a server, which also means you can use these on client data without asking anyone's permission.