Free CDL Practice Tests
158+ real exam-style questions across 8 tests — General Knowledge, Air Brakes, and every endorsement. Instant answers, explanations, and a fresh shuffle every attempt. No sign-up.
O TruckingPass Your CDL Knowledge Test the First Time
Key Takeaways
- General Knowledge is required for every CDL — start there.
- Class A drivers also need Combination Vehicles and (for air-brake trucks) Air Brakes.
- Endorsements — HazMat, Tanker, Doubles/Triples, Passenger, School Bus — are separate tests.
- Every question shows the correct answer and an explanation instantly.
- Most states require 80% to pass the real knowledge test.
Core knowledge tests
General Knowledge
Required for every CDL applicant. Covers inspection, control, space & speed management, hazards, skids, emergencies, and cargo.
24 questionsAir Brakes
Removes the air-brake restriction. Covers the air brake system, dual systems, warnings, spring brakes, and the inspection & leakage tests.
20 questionsCombination Vehicles
Required for a Class A CDL. Covers coupling & uncoupling, the fifth wheel, air lines, off-tracking, and rollover prevention.
20 questionsEndorsement tests
Hazardous Materials
The H endorsement. Covers the 9 hazard classes, placarding, shipping papers, loading rules, and emergency response.
22 questionsTank Vehicles
The N endorsement. Covers liquid surge, outage, baffled vs. smooth-bore tanks, high center of gravity, and safe handling.
18 questionsDoubles & Triples
The T endorsement. Covers coupling twin trailers, the converter dolly, rearward amplification, and inspecting the rig.
18 questionsPassenger
The P endorsement. Covers bus inspection, loading & unloading, the standee line, railroad crossings, and prohibited practices.
18 questionsSchool Bus
The S endorsement. Covers the danger zone, mirrors, the loading/unloading procedure, railroad crossings, and evacuation.
18 questionsReady for the road after your CDL?
Once you have your license, find an FMCSA-registered school in our truck driving schools directory, or when you go independent, let O Trucking dispatch you for a flat weekly rate.
See how dispatch worksCDL practice test FAQ
Are these CDL practice tests free?
Yes — every test here is completely free, with no sign-up. Each question shows the correct answer and an explanation the moment you answer.
What score do I need to pass the real CDL test?
Most states require 80% to pass each knowledge test. Our results screen flags whether you hit 80% so you know when you're ready.
Which CDL tests do I need to take?
Every applicant takes General Knowledge. For a Class A you'll also need Combination Vehicles, and Air Brakes to drive an air-brake vehicle. Endorsements (HazMat, Tanker, Doubles/Triples, Passenger, School Bus) are separate tests you take only if you need them.
Are the questions based on the official CDL manual?
Yes. Every question and explanation is grounded in the AAMVA model CDL manual and FMCSA regulations. They're practice questions, not the exact exam questions, but they cover the same rules.