UWorld can be useful extra drilling after you have used official ACT questions. It is not a substitute for a timed official core of 50 English, 45 Math, and 36 Reading.
What it does well
Explanations are often clearer than a score report. Use it for one weak topic—commas, functions, or science-style graphs—after you already know the official timing. Kaplan and PR sit in the same "second bank" bucket: is Kaplan worth it.
What it does not replace
Official tests still set the clock and the wording. Is the official guide enough, free official practice.
The bottom line
Drill with UWorld if explanations help you learn. Score yourself on official sections. Do not treat a UWorld percent as a Composite.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.