Why CDL practice tests matter
The CDL written exam isn't designed to be tricky — it's designed to make sure you actually know the federal regulations that govern how a commercial vehicle is operated. The questions come from the FMCSA Commercial Driver's License Manual, and they cover real situations: a tire blowout at highway speed, a brake failure on a downhill grade, a load that shifts mid-turn, an emergency at a railroad crossing.
Reading the Manual once gets most applicants partway there. What practice tests do is expose the gaps — the topics where you think you know the rule but actually don't. After a few attempts, you'll know exactly which sections to re-read. That's the difference between passing on the first try and paying for a second DMV appointment a month later.
Every test on this site is free, requires no account, and has no time limit. Take any test as many times as you need — questions reshuffle on every attempt, and you'll see an explanation after each answer.
Which CDL endorsements do you need?
The endorsement combination depends on the job. Here's the practical breakdown most CDL applicants follow.
If you're getting a Class A CDL
You'll take three written tests: General Knowledge (Class A), Combination Vehicles, and Air Brakes. The Air Brakes test is technically optional, but skipping it means you'll get a restriction on your license that blocks you from driving any vehicle with air brakes — which is almost every commercial truck. From there, add HAZMAT, Tanker, Doubles/Triples, or other endorsements based on what you'll haul.
If you're getting a Class B CDL
You'll take General Knowledge (Class B) and almost always Air Brakes. Class B vehicles — dump trucks, garbage trucks, transit buses, and large straight trucks — are mostly air-braked. School bus drivers need both Passenger and School Bus endorsements on top of General Knowledge B.
If you'll haul hazardous materials
The HAZMAT endorsement requires both a written test and a TSA background check that takes 30 to 60 days. Apply for the TSA check before your DMV appointment so the wait runs in parallel with your studying. Fuel haulers typically need HAZMAT plus Tanker — sometimes informally called the X endorsement.
What to expect on the CDL written exam
Each endorsement has its own test. Question counts vary: General Knowledge is about 50 questions, HAZMAT is about 30, Air Brakes and Combination Vehicles are about 25, and Tanker, Doubles/Triples, Passenger, and School Bus are about 20 each. Most states require 80% to pass. A few states are slightly higher.
The exam is administered at your state DMV or a designated third-party testing center. You'll need identification, proof of residency, and your medical certificate (DOT physical) before scheduling. Tests are usually administered on a computer with multiple-choice questions. You can retake failed tests, but most states require a waiting period and an additional fee for each retake.
Before the written exam comes a separate requirement: ELDT theory training. Federal law requires entry-level CDL applicants to complete FMCSA-registered theory training from an approved provider before they can sit for the skills test. If you haven't done this yet, you'll need to handle it — we recommend ELDT365 for fast online completion.
How to use this site effectively
The most reliable path through the CDL written exam looks like this. First, read your state's CDL Manual cover-to-cover. It's free at every state DMV website. Don't skip sections that look familiar — the test pulls from every chapter. Second, take the practice test for whichever endorsement you're studying. Don't worry about your score on the first attempt; you're mapping the territory.
Third, identify your weak topics. If you keep missing questions on slack adjusters, spend ten minutes in the Air Brakes chapter of the Manual on that one subsection. Then come back and retake the test. Fourth, repeat until you hit 90%+ on three consecutive attempts. At that point you're ready for the DMV.
Every test on MyCDLPractice reshuffles questions on every attempt, so you can't accidentally memorize the order. Each question shows you the correct answer and a short explanation immediately after you tap, so each attempt is also a study session. There's no time limit and no penalty for guessing — learn the material, not the test.