Straight answers
What device do I need for the digital SAT?
You need a Windows laptop or tablet, a Mac laptop, an iPad, or a school-managed Chromebook — and it has to run the Bluebook app. A phone will not work, and neither will a personal Chromebook that your school does not manage. If a student has no eligible device, ask the school first, then a friend or family member; if none of those works, College Board may be able to lend one, requested through My SAT at least 30 days before test day.
The physical requirements are the ones families miss. Laptop screens have to be at least 10 inches and tablets at least 8 inches, so a small tablet that is fine for homework may not be allowed in the room. The device has to hold a charge for roughly three hours of testing — bring the power cord or a portable charger anyway, because there is no guarantee of an outlet at your seat. And if the student is testing on a laptop, a separate external keyboard is not permitted.
Operating-system minimums exist for Windows, macOS, and iPadOS, and they move. College Board raises the floor as versions age out, which means a device that was approved last spring can quietly stop qualifying. Check Bluebook's approved-devices page for the current minimums rather than trusting any third-party list, including this one — we can tell you the shape of the rule accurately, but not the version number that will be true on your test day.
Install Bluebook and complete exam setup before test day, not on test day. Exam setup downloads what the app needs and confirms the device is ready; doing it in the parking lot on a school network you have never used is how a manageable morning becomes a bad one. A few days ahead is the right window.
About borrowed devices, in College Board's own order of preference: ask the school, then a friend or family member, and only then request a College Board loaner in My SAT — that last one is “may be able to”, not a guarantee, and its deadline is firm at 30 days before test day. Waiting until the week before is too late for all three.
Brainrise runs in a browser on any device, including a phone, because daily practice should fit in the fifteen minutes a student actually has. That is deliberately a different constraint from test day: practice anywhere, but make sure the machine you will actually test on is approved and set up long before it matters.