Pass your CDL on the first try.
Free, ad-supported practice tests for every U.S. state and every CDL endorsement — 479 real questions written from the official AAMVA Commercial Driver License Manual, the same handbook your state DMV uses.
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Practice by endorsement
Every CDL applicant starts with the General Knowledge test. After that, your endorsements depend on the kind of driving job you want — freight, fuel, passenger, school bus, hazmat, or longer combinations. Pick your test below to see hundreds of real-style questions with instant scoring and explanations.
General Knowledge
The General Knowledge exam is required for every CDL applicant in the United States, regardless of which class of license (Class A, B, or C) you intend to hold.…
65 practice questions →
EndorsementAir Brakes
The Air Brakes endorsement is required if the commercial vehicle you plan to operate is equipped with an air brake system, including air-over-hydraulic brakes. …
65 practice questions →
EndorsementCombination Vehicles
The Combination Vehicles knowledge exam is required for a Class A CDL, which authorizes you to operate any combination of vehicles with a gross combination weig…
65 practice questions →
EndorsementHazardous Materials
The Hazardous Materials endorsement (code H on your license) lets you transport materials that the U.S. Department of Transportation classifies as hazardous in …
61 practice questions →
EndorsementTanker
The Tank Vehicle endorsement (code N) is required to drive any commercial vehicle hauling liquids or liquefied gases in tanks with an individual rated capacity …
64 practice questions →
EndorsementDoubles & Triples
The Doubles and Triples endorsement (code T) is required to pull more than one trailer. Because doubles and triples handle very differently from a single tracto…
59 practice questions →
EndorsementPassenger
The Passenger endorsement (code P) authorizes you to drive a vehicle designed to transport 16 or more passengers, including the driver. Examples include city tr…
50 practice questions →
EndorsementSchool Bus
The School Bus endorsement (code S) is required for anyone who operates a school bus, in addition to a Passenger (P) endorsement. The school bus exam draws from…
50 practice questions →
Practice by state
Each U.S. state issues its own commercial driver license, but every state's CDL knowledge exam is built on the same federal model maintained by AAMVA on behalf of the FMCSA. We list the official DMV agency for every state plus all eight endorsement tests you can take there.
Why drivers trust CDL Prep Hub
Real questions
Every question is derived from the official AAMVA Model Commercial Driver License Manual, the source every state DMV uses to write its handbook. No clickbait, no junk. Each answer is explained with the manual section it comes from so you understand why.
Instant feedback
Pick an answer, see immediately whether it was right, and read a short explanation that ties back to the same chapter your state examiner is working from. The fastest way to lock in the rules of the road for a commercial driver.
Free forever
No login. No paywall. No upsell to a paid app. Ad-supported so we can keep these tests free for the truck drivers, school bus operators, and transit drivers who keep this country moving.
How the CDL knowledge test works
The Commercial Driver's License is a federal credential administered by every U.S. state under the rules of the Federal Motor Carrier Safety Administration (FMCSA). Before you can drive a commercial vehicle on a public road, you must hold a CDL of the proper class, with the proper endorsements for what you'll be hauling.
Most states require an applicant to pass written knowledge exams covering general commercial vehicle operation, plus any endorsement-specific knowledge tests, before they can take the behind-the-wheel skills test. The General Knowledge exam is required for every applicant. Air Brakes, Combination Vehicles, Hazardous Materials, Tank Vehicles, Doubles & Triples, Passenger, and School Bus are taken depending on the vehicle and cargo you intend to operate.
Passing scores are usually 80% or higher. Questions are multiple choice. Most state DMV exams pull directly from the same source we use here: the AAMVA Model CDL Manual. If you can answer the questions on this site confidently and understand the reasoning behind each answer, you will be very well prepared for the actual exam.