Pass your CDL knowledge test with the most complete offline prep tool.

CDL Trainer USA is a complete practice tool for the U.S. commercial driver's license knowledge exam, based on the official FMCSA CDL Manual. 855 unique questions written for the exam — no filler, no duplicates — with an explanation for every answer.

HOW IT WORKS
• Start with General Knowledge — all 125 questions, plus 30 road signs, open to everyone
• Unlock everything else with one purchase inside the app: Air Brakes, Combination Vehicles, Pre-Trip Inspection, all endorsements, all 198 road signs, 28 diagrams, ELD trainer, hazard perception and exam mode
• One-time purchase. No subscription. No ads. No registration.
• 100% offline — study in your truck, no internet needed

WHAT'S INSIDE
• 855 questions across all test sections: General Knowledge, Air Brakes, Combination Vehicles, Pre-Trip Inspection, Hazard Awareness, Hours of Service & ELD, Basic Control Skills, On-Road Driving + endorsements (Tanker, Doubles/Triples, HazMat, Passenger, School Bus)
• Exam-like structure: the same number of questions and the 80% passing score as at the DMV, separate Practice / Exam counters, PASS/FAIL marks
• DMV-style exam screen — skip, flag "return later", review before you submit
• 198 road signs with authentic MUTCD artwork — exam-required signs are marked
• Hazard perception — 25 photos from the driver's seat, 8 seconds to decide: Brake / Ease off / Nothing (the Dutch CBR scheme; no other US CDL app has it)
• 28 technical diagrams for Air Brakes and Pre-Trip Inspection — compressor, governor, S-cam brake, slack adjuster, spring brake chamber, glad hands, fifth wheel, landing gear, suspension, tires and more. Every numbered part is explained.
• ELD ProTrainer — 8 interactive Hours-of-Service scenarios on a realistic ELD screen
• "In plain words" — every section explained in about 10 simple sentences
• English terms glossary — 40 key trucking terms with search
• Search the whole app — questions, explanations, summaries and glossary in one place
• Your state — official CDL manual and agency links for all 50 states + DC, and only what differs from the national standard (permit validity, third-party testing, extra requirements)

Official website: www.cdltrainer-usa.com