Pass your CDL test the first time.
CDL Prep Hub gives you 526 free practice questions covering every Commercial Driver's License knowledge exam — General Knowledge, Air Brakes, Combination Vehicles, Hazmat, Tanker, Doubles & Triples, Passenger, and School Bus — written from the AAMVA CDL Manual and grouped by U.S. state.
Practice tests by endorsement
Each test below mirrors the structure of the official knowledge exam administered by every U.S. state licensing agency. Click any category to see all of its practice questions with the correct answer and a written explanation.
General Knowledge
The mandatory test every CDL applicant must pass: vehicle inspection, control, signaling, hazards, and safe operation.
Practice now →Air Brakes
Required for any vehicle equipped with air brakes — covers compressors, governors, slack adjusters, and emergency systems.
Practice now →Combination Vehicles
Class A endorsement test: coupling, fifth wheels, glad hands, off-tracking, and pulling tractor-trailers.
Practice now →Hazardous Materials (Hazmat)
Required to carry placardable hazardous materials — paperwork, placards, segregation, routing, emergencies.
Practice now →Tank Vehicles
Required for liquid or gas tanks of 1,000 gallons or more — surge, baffles, outage, and rollover prevention.
Practice now →Doubles / Triples
Required to pull more than one trailer — converter dollies, pintle hooks, and crack-the-whip control.
Practice now →Passenger Transport
Required for buses and other vehicles designed to carry 16 or more passengers, including the driver.
Practice now →School Bus
Required to drive a school bus — danger zones, loading/unloading, and student management.
Practice now →Find your state
Although the federal CDL knowledge exams are uniform, each state's licensing agency runs its own scheduling, fees, and skills test. Pick your state to see local information, plus the same complete bank of practice questions.
California
Practice CDL questions geared for drivers testing in California.
Texas
Practice CDL questions geared for drivers testing in Texas.
Florida
Practice CDL questions geared for drivers testing in Florida.
New York
Practice CDL questions geared for drivers testing in New York.
Pennsylvania
Practice CDL questions geared for drivers testing in Pennsylvania.
Illinois
Practice CDL questions geared for drivers testing in Illinois.
Ohio
Practice CDL questions geared for drivers testing in Ohio.
Georgia
Practice CDL questions geared for drivers testing in Georgia.
How CDL Prep Hub works
Studying for a Commercial Driver's License is a serious time investment. Most candidates spend two to four weeks reading their state's CDL manual, attending school, or driving with a learner's permit. CDL Prep Hub is built to be the supplement you can pick up at any moment — at the truck stop, at the kitchen table, or in the cab during a ten-hour break — to test what you've learned and reinforce the rules that actually appear on the exam.
Every question on this site is presented exactly the way you'll see it on test day: a single multiple-choice item with four answer choices, the correct answer revealed alongside, and a written explanation that ties the answer back to the rule in the AAMVA CDL Manual or the relevant federal regulation. There are no quizzes to time, no scores to track, no accounts to create — just plain, indexable practice content.
The General Knowledge bank includes 228 questions reproduced from a public-domain dataset of historic exam material. The endorsement banks (Air Brakes, Combination Vehicles, Hazmat, Tanker, Doubles & Triples, Passenger, and School Bus) were written from the AAMVA Commercial Driver License Manual chapter summaries and 49 CFR rules. The full data source is documented in the project's README.
What you'll find
- One page per question — each of the 526 practice items has its own permanent URL, so you can bookmark, share, or revisit any question.
- Endorsement category indexes — see every question in a single category at a glance, with the question text and a link to the full page.
- State pages for all 50 states & DC — quick reference for the licensing agency in your state, what age limits apply, and what to expect on test day.
- A printed-style study guide — high-level coverage of the rules and habits that show up on every CDL knowledge exam.