CDL Prep Hero

CDL Prep Hero helps you study for US commercial driver's license knowledge tests with short lessons, visual explanations and practice questions. Available in English and Spanish. BUILD UNDERSTANDING Learn how air brakes work, why trailers follow different paths through a turn, and the principles behind safer commercial driving. Read-aloud and animated diagrams support the lesson text. PRACTICE FOR YOUR SUBJECTS Choose your state, license class and endorsements. Study relevant lessons, practice questions, review missed answers, save questions for later and take mock exams. Coverage includes general knowledge, air brakes, combination vehicles, tank vehicles, hazardous materials, doubles and triples, passenger and school bus. START FREE Try the free lessons and a ten-question sample test without creating an account. 90 DAYS OF FULL ACCESS Unlock the full course with one payment through Google Play for 90 days. No automatic renewal. Sign in with Google before purchasing or restoring access. Restore using the same Google Account; restoring does not restart the 90 days. An internet connection is required for account and purchase verification. YOUR PROGRESS, ON YOUR PHONE Track lessons, practice and mock-exam results. The readiness score summarizes study activity and performance; it does not predict or guarantee a passing result. Study progress and saved questions remain on the device and do not sync between phones. ENGLISH OR SPANISH Study in the language you're most comfortable with. Switch between English and Spanish at any time in Settings; your progress stays the same. CDL Prep Hero is an independent study aid, not affiliated with a DMV, the FMCSA or the US Department of Transportation. It does not replace your state's official CDL manual, required training or official tests. Do not use the app while driving.