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CDL Prep · Free on web, iOS & Android

The CDL Prep app that knows when you're ready to pass

Free CDL practice tests that mirror the real exam: same question counts and time limits, every answer explained, and an IQ Readiness Score that tells you when to book your test.

2,800+ CDL questionsAll 50 statesFree to start

9:41
Choose a CDL exam

Real CDL applicants take a separate written test per section. Each simulation uses the actual question count and time limit.

50General Knowledge50 questions · 90 min · 80% to pass
25Air Brakes25 questions · 30 min · 80% to pass
20Combination Vehicles20 questions · 25 min · 80% to pass
HHazMat30 questions · 40 min · 80% to pass
NTanker20 questions · 25 min · 80% to pass
PPassenger20 questions · 25 min · 80% to pass
IQ Readiness · Air Brakes
0%Ready
Ready to book

Free CDL practice tests for every section

Every set is free, drawn from FMCSA-aligned questions, with every answer explained. Pick a section to practice on the web, or get the app to study on your phone.

General Knowledge

50 questions · 90 min · 80% to pass

Every CDL starts here. Vehicle control, safe driving, and cargo basics that every commercial driver must pass, regardless of class.

Air Brakes

25 questions · 30 min · 80% to pass

Removes the air brake restriction from your CDL. Covers system components, inspection steps, and braking with air-equipped vehicles.

Combination

20 questions · 25 min · 80% to pass

Required for Class A. Coupling and uncoupling, trailer handling, and preventing rollovers and jackknifes in tractor-trailer rigs.

Pre-Trip Inspection

Skills test · Part 1

The first part of the skills test and the most failed. Learn the full inspection sequence before you start the engine on test day.

HazMat(H)

30 questions · 40 min · 80% to pass

Transport hazardous materials. Placarding, loading rules, and emergency response. Requires a TSA background check in every state.

Tanker(N)

20 questions · 25 min · 80% to pass

Drive tank vehicles carrying liquids or gases. Surge control, baffled vs. unbaffled tanks, and the handling risks of liquid loads.

Passenger(P)

20 questions · 25 min · 80% to pass

Carry 16 or more passengers. Loading, emergency exits, railroad crossings, and the rules that apply to buses of every kind.

School Bus(S)

20 questions · 25 min · 80% to pass

The most regulated endorsement. Student loading zones, danger zones around the bus, and emergency procedures. Requires P first.

Doubles/Triples(T)

20 questions · 25 min · 80% to pass

Pull double or triple trailers with a Class A. Coupling sequence, crack-the-whip effect, and multi-trailer stability.

See all CDL practice tests and study by state →

What you get with DMV IQ

A CDL prep app built to get you licensed faster, not to pad your study time.

IQ Readiness Score™

One 0 to 100 score per section, built from how well you know the material and how well it sticks. When it hits the ready zone, book your test.

0/ 100Ready to book
94%
Likely to pass
8/9
Sections ready
1
Needs review

Learns your weak spots

Missed questions come back right before you would forget them, and your mastery in every CDL section stays in view.

General Knowledge92%
Combination Vehicles74%
Air Brakes61%
Hazardous Materials38%

Pro tracks your mastery in every CDL section, so you always know exactly what to drill next.

How CDL Prep works

1

Pick your section

Choose General Knowledge or the endorsement you need. The app pulls FMCSA-aligned questions for your state.

2

Practice like the real test

Run timed simulations at the real question count, review every explanation, and drill the topics you miss.

3

Watch your readiness climb

Your IQ Readiness Score rises as you master each topic. When it hits the ready zone, book your test.

CDL practice tests by state

Knowledge tests vary by state. DMV IQ matches questions and formats to your state's CDL manual.

Common questions about CDL prep

It depends on the section. General Knowledge is 50 questions, Air Brakes 25, and most endorsements 20 to 30. You need 80% to pass any of them. DMV IQ runs each practice test at your state's real count and time limit.
Yes. They come from the same FMCSA material the states build their tests from, and each simulation uses the real question count, time limit, and 80% passing mark. They are practice questions, not copies of the live exam.
The practice tests are free on the web and in the app, with every answer explained and no account required to start. Pro is optional and adds unlimited retakes and full readiness tracking.
Your IQ Readiness Score turns your practice history into one 0 to 100 score per section. It weighs how well you know each topic and how well it is sticking, so when a section reaches the ready zone, your odds of passing the first time are high.
Every CDL knowledge test: General Knowledge, Air Brakes, Combination, and Pre-Trip, plus the HazMat, Tanker, Passenger, School Bus, and Doubles/Triples endorsements. HazMat also requires a TSA background check, which we walk you through.
The CDL knowledge test is federal, so the content is the same everywhere. DMV IQ tailors the questions and format to your state's manual across all 50 states and D.C.
Yes. The iOS and Android apps work fully offline, so you can study on a break or between loads. On the web you just need a browser, with no download.

Ready when you are

Get the app and study anywhere, or start a free practice test in your browser.

Free CDL Prep App & Practice Tests for Every Endorsement | DMV IQ