CDL practice tests built like the real permit tests
Take a free 20-question diagnostic and see which CDL topics you'd miss today. Then practice every knowledge test you need: general knowledge, air brakes, combination and the endorsements.
Start the free diagnostic- 1,008 practice questions with explanations
- Full-length timed mock exams
- $24 once · 90 days · no subscription
- 30-day money back
The real CDL knowledge tests
- Each knowledge test needs 80% to pass. That's a federal rule (49 CFR 383.135), so it's the same in every state.
- Every state builds its tests from the same FMCSA-approved AAMVA test system, so the questions follow the same CDL manual everywhere.
- Test lengths in Washington's official table, which most states match: general knowledge 50 questions (40 to pass), air brakes 25 (20), combination 20 (16), hazardous materials 30 (24), tank vehicle, doubles/triples, passenger and school bus 20 each (16).
- Your state sets the fee, the number of tries and any time limit, and may add a few state rules. Check your state's CDL manual too.
Sources: 49 CFR 383.135: passing knowledge tests (80%) · 49 CFR 383.133: states use the FMCSA-approved AAMVA test system · Washington DOL: CDL knowledge tests (questions and passing scores) · FMCSA: commercial driver's license program
How it works
Take the free diagnostic
20 questions from across the exam. No email, no card.
See your weak topics
Your score, a breakdown by topic and the right answer with an explanation for each question.
Practice until you're ready
Unlock everything for $24: the full bank, mock exams and drills.
Full CDL access
- Every CDL knowledge test: general knowledge, air brakes, combination vehicles, hazardous materials, tank vehicles, doubles/triples, passenger and school bus, plus pre-trip inspection
- Mock tests at the real lengths, scored at 80% like the real thing
- An explanation for every answer
- Drills on the topics you miss most, and a list of every question you got wrong
- Progress saved to your account, on any phone or computer
You can also . 30-day money back: one tap in your account.
Questions
Is this the official CDL test?
No. PrepOak is an independent practice service. The real tests are given by your state. Our questions follow the CDL manual that every state's test is built from, so they cover the same topics.
Which tests are included?
All of them: general knowledge, air brakes, combination vehicles, hazardous materials, tank vehicles, doubles/triples, passenger and school bus, plus pre-trip inspection practice.
Does it work for my state?
Yes for the federal topics, which are most of every test. A few states add their own rules, so read your state's CDL manual for those.
How long do I have access?
90 days from the day you pay. It's one payment, not a subscription, so nothing renews.
What if it doesn't help me?
Use the Refund button in your account within 30 days of paying and you get all your money back at once. Your access ends when you're refunded.
Do I need to create an account?
No password. We set up your account from the email you give at checkout and send you a sign-in link.
PrepOak is not affiliated with or endorsed by the FMCSA, AAMVA or any state licensing agency. Our questions are written for practice; they are not the official test questions. No practice test can promise you'll pass.