Free CDL Practice Test
32 questions covering the CDL written tests. Vehicle inspection and control, safe driving and hazards, air brakes, and combination vehicles and endorsements. Most states require 80% to pass.
15 minutes, 32 questions
Four sections covering General Knowledge plus the two most common endorsements.
The 80% standard
Most states require 80% on each written test. We apply the same bar.
Full section breakdown
Air brakes or inspection? See which test you are ready to sit.
What is the CDL?
A Commercial Driver’s License is required to drive most large or heavy vehicles in the United States, including tractor-trailers, buses and tankers. It is the entry qualification for one of the better-paid skilled trades you can enter without a degree.
The written stage is not one test but several. Everyone takes General Knowledge. Beyond that you take a separate written test for each endorsement or vehicle type you need: Air Brakes, Combination Vehicles, Hazmat, Tanker, Doubles/Triples, Passenger and School Bus. Most states require 80% on each.
What this practice test covers
Thirty-two questions across the areas that matter most: vehicle inspection and basic control, safe driving and hazard perception, air brakes (the endorsement almost every driver needs) and combination vehicles and endorsements, including the rules for Hazmat, tankers and school buses.
How your score is interpreted
We apply the 80% threshold most states use, so 26 correct is the equivalent pass mark:
The section that fails most candidates
Air brakes. It is technical, it is unfamiliar to anyone coming from cars, and it is full of specific numbers and mechanisms — governor cut-in and cut-out, the low pressure warning below 60 psi, brake lag, why fanning the brakes on a downgrade causes failure, and why spring brakes apply automatically when pressure drops. None of it is intuitive. If you have limited study time, put it here.
One practical consequence worth knowing: if you do not pass the air brakes test, your licence is restricted and you cannot operate a vehicle with air brakes — which rules out most of the jobs people get a CDL for in the first place.
Rules that differ from car driving
Two catch people out repeatedly. The blood alcohol limit for a commercial driver on duty is 0.04%, half the limit for car drivers. And refusing a required drug or alcohol test is treated exactly the same as failing one — there is no advantage in declining. Both are heavily examined and both have career consequences.
Before you go
Get your state CDL manual, which is published free, and check the current federal requirements: since the ELDT rule, new applicants must complete entry-level driver training with a registered provider before taking the skills test. Requirements around medical certification and self-certification categories also vary, so confirm what your state asks for before paying for anything.
Frequently asked questions
No. This is an independent practice test built by Quizinq for study purposes. It is not affiliated with or endorsed by any state licensing agency or the FMCSA. Official tests must be taken at your state licensing office.
Most states require 80% on each written test. You take General Knowledge plus a separate test for each endorsement you need.
If you plan to drive a vehicle with air brakes — which is most commercial vehicles — yes. Failing it means an air brake restriction on your licence, which rules out most CDL jobs.
A written test plus a Transportation Security Administration background check, which takes time and carries a fee. Start it early if you need it. See all our quizzes.
It covers the federal content that is consistent nationwide, which is most of the question bank. Some state-specific rules differ, so read your state CDL manual alongside this.