Loading...
Prepare for your CDL with confidence
Complete Commercial Driver's License preparation — general knowledge, air brakes, hazmat, tanker, and all endorsements with realistic practice tests. Study aid only; not affiliated with FMCSA or any state DMV.
Explore by topic
General Knowledge
CDL basics, vehicle systems, safe driving practices, and cargo handling.
Class AClass B
Air Brakes
Air brake systems, components, inspection procedures, and emergency stops.
Class AClass B
Hazmat
Hazardous materials classification, placarding, loading, and emergency response.
Endorsement
Tanker
Liquid cargo handling, surge control, and tanker-specific safety procedures.
Endorsement
Combination Vehicles
Coupling/uncoupling, jackknife prevention, and doubles/triples operation.
Class A
Passenger & School Bus
Passenger safety, school bus operations, railroad crossings, and evacuation.
Endorsement
What makes Koydo CDL different
Practice Tests
Hundreds of questions modeled after the real CDL written exam.
Pre-Trip Videos
Watch and learn the complete pre-trip inspection sequence.
Score Tracking
Track your readiness by section and know when you're ready.
Always Free
No hidden fees. Complete CDL prep at zero cost.
Ready to start learning?
8,000+ modules across every major subject. No Ads Ever. Start with free access — no card required.
Start free