Free CDL practice tests, every endorsement
145 questions across 8 knowledge areas, from general knowledge and air brakes through to hazmat, tanker, doubles and triples, passenger and school bus. Nothing is held back and there is no paid tier.
Where these questions come from. State CDL manuals are published by AAMVA and are copyrighted, so we do not use them. Every question here is written from federal law instead, chiefly 49 CFR Part 383, and cites the provision it tests. That is the same law the state manuals are built on, which is why the material matches while the words are our own.
Take the ones your licence needs
Everyone sits general knowledge. Air brakes matters to almost everyone, because failing it adds an L restriction that bars you from most commercial vehicles. The rest depend on what you intend to drive and haul.
General Knowledge
Required of every applicant: inspection, control, space and speed management, hazard perception, emergencies and hours of service.
Air Brakes
Fail this and an L restriction bars you from any vehicle with air brakes, which is most of them.
Combination Vehicles
Coupling, the fifth wheel, off tracking and trailer swing. Needed for Class A.
Hazardous Materials
Placards, shipping papers, segregation and the security threat assessment.
Tank Vehicles
Liquid surge, baffles, outage and why a tanker rolls over so readily.
Doubles and Triples
Rearward amplification, converter dollies and coupling a second or third trailer.
Passenger Transport
Bus inspection, standee lines, passenger supervision and railroad crossings.
School Bus
Danger zones, loading and unloading, student crossing and evacuation.
CDL rules by state
The knowledge material is federal, so it does not change at a state line. What does change is the commercial learner permit, the fees and who administers the skills test.
What the CDL process actually involves
A commercial licence is not one test. You take a general knowledge exam, then a separate written exam for each endorsement you want, then a skills test in a vehicle representative of the class you are applying for. The written exams are the part you can do from a sofa, which is what this site is for.
Two things trip people up. Air brakes is technically optional, but skipping it puts an L restriction on your licence that rules out most commercial vehicles, so it is optional in name only. And since February 2022 federal entry level driver training has been required before you can take the skills test for a first CDL, an upgrade, or a hazmat, passenger or school bus endorsement.
Everything on this site applies to the written exams. Nothing here replaces the training or the time behind the wheel.