Questions

Yes. Know Your Buy is free for buyers.

Anyone buying a used Windows laptop in person, especially if you're not technical. It turns hardware readings into a plain answer: buy, negotiate or walk away.

Yes. There is a Mac version for used MacBooks (Apple Silicon M1 to M4, and Intel Macs from 2018, on macOS 13 or newer). On a Mac it also checks iCloud Activation Lock and company management (MDM), which make a used Mac worthless after a reset. Download the version for the Mac you are testing: Apple Silicon or Intel. The Windows version is for Windows laptops.

Not yet. Today it tells you what's wrong and, for common fixes like a battery or a cooling clean, a rough repair cost to take off the price. A fair-price estimate is planned.

Run All takes about 8 minutes. The optional stress test adds 1, 3 or 5 minutes.

No. It works completely offline and uploads nothing.

No. Copy KnowYourBuy.exe to a USB stick and run it from there. It may offer an optional temperature driver, which Clean up & Exit removes again.

Windows only lets administrator apps read temperatures, fan speeds and drive health. If the laptop asks for a password, the seller types it.

Many laptops hide their fan speed from Windows. Know Your Buy hides the Fan test on those laptops; the processor test still catches overheating.

Yes. Every test has its own button. Run All runs them in the best order.

Some laptops report numbers badly, and some counters can be reset. That's why every result shows a confidence level: High, Medium or Low. Treat Low results as a hint and check that part another way.

The laptop works, but something will cost money soon, like a worn battery or a processor that runs hot. The report says what and, where possible, roughly how much.

A hard failure on a part that's expensive or impossible to replace: processor or memory errors, graphics errors or freezing, a drive that reports it's failing, or errors in the stress test.

Not yet. The buyer's guide has a 2-minute checklist for the screen, keyboard, speakers, webcam and ports while Know Your Buy runs.

Not yet. It shows the real specs Windows reports, so compare them with the listing. Dedicated fake-spec checks are planned.

No. It installs nothing, doesn't touch anyone's files, writes at most 1 GB of test data and deletes it, and cleans up when you exit. The laptop will get hot and loud during the load tests, which is normal.

No. The app makes no network connections. Reports are saved only on your USB stick.

No. It's SmartScreen, which warns about apps it hasn't seen often. Click More info, check the name says KnowYourBuy.exe, then Run anyway. The download page explains how to check your copy is genuine.