Study Smarter for Your
CDL Knowledge Test
Practice exams, narrated guides, and endorsement modules, organized by CDL class and state.
Everything You Need in One Place
Organized by Module
Topics broken into focused modules: General Knowledge, Air Brakes, Combination Vehicles, and every endorsement. Study what you need, skip what you don't.
Narrated Audio
Listen and review anywhere. Audio modules reinforce written material so drivers can study during a commute, break, or haul.
State-by-State Info
Agency links, state profiles, major industries, and state-specific notes for all 50 states plus DC, so you know who to contact.
All 7 CDL Endorsements Covered
Air Brakes
Required for any vehicle equipped with an air brake system — covering most Class A tractor-trailers…
Study Air Brakes →Combination Vehicles
Essential for Class A drivers operating tractor-trailers, lowboys, and other multi-unit combination…
Study Combination Vehicles →Hazardous Materials
Required to transport any quantity of hazardous materials that require placarding under federal Haz…
Study Hazardous Materials →Tank Vehicles
Required for vehicles designed to transport liquids or gases in a tank permanently or temporarily a…
Study Tank Vehicles →Passenger
Required for commercial vehicles designed to carry 16 or more passengers including the driver — cha…
Study Passenger →School Bus
Required for any driver transporting school-age students in a vehicle classified as a school bus un…
Study School Bus →Doubles & Triples
Required to pull double or triple trailers where permitted by state law — common in regional and lo…
Study Doubles & Triples →Not sure which CDL you need?
Answer a few questions and the selector tool gives you a starting point based on your vehicle and operation.
Use the CDL Selector →Common Questions
What CDL class do I need?
It depends on the vehicle weight rating, trailer weight, passenger use, school bus use, and whether hazardous materials are transported. The selector tool gives a starting point, and your state licensing agency makes the final determination.
Do I need ELDT before testing?
ELDT generally applies when you are getting a Class A CDL, Class B CDL, Class B-to-Class A upgrade, or a Passenger, School Bus, or HazMat endorsement for the first time.
Is HazMat ELDT different?
Yes. HazMat ELDT is theory training and must be completed before the hazardous materials knowledge test. The TSA security threat assessment is a separate requirement.
Can I study before buying training?
Yes. You can compare CDL classes, review endorsement topics, and use the selector tool first. Paid products add organized practice modules, PDFs, audio, and training access.