Starting in the spring of 2024, the College Board will beging using a new SAT which will be both shorter and all digital. Students will still sit for the exams in school or at a testing site.
Shorter test time:
The test will be 2 hours in length but scoring will remain on a 1600 point scale.  Calculators will be allowed on all math questions.
Other changes:
The test will be “adaptive,” which means that students’ answers to questions will affect what questions they get in later sections  of the exam. More specifically, the reading, writing and math sections of the exam will be split into two modules. How students answer questions in the first module will impact the questions they see in the second module.  Questions in the first module will have a range of difficulty levels, just like the current SAT exam.
https://newsroom.collegeboard.org/digital-sat-brings-student-friendly-changes-test-experience