Professor Messer and Jason Dion are the two names that dominate every CompTIA study recommendation thread. They are not direct competitors — they're complements — but most candidates can only afford the time (or money) for one. This page compares them head-to-head on the dimensions that actually affect whether you pass on the first try: concept depth, practice exam realism, PBQ exposure, and total cost.
By the end you'll know which to pick if you can only choose one, and the lean way to use both if you want the strongest possible prep.
Professor Messer wins on free concept teaching; Jason Dion wins on practice exam realism and PBQ exposure. The most common winning approach is to use both: Messer's free videos for the core content, then Dion's Udemy practice exams ($15–20 on sale) for exam-day realism. Choosing only one? Messer if budget is zero, Dion if you already know the material and need exam practice.
What Each Is Known For
Professor Messer (James Messer) is a 20-year IT veteran who built his audience on completely free YouTube video courses covering CompTIA A+, Network+, and Security+. His teaching style is calm, structured, and objective-mapped. His paid products are course notes ($25) and three practice exams ($25 per cert).
Jason Dion is a former DoD instructor whose business is built around Udemy. He sells video courses ($15–25 on sale) and — more importantly — full-length practice exam packs that are widely considered the most exam-realistic on the market. His practice exams include PBQs, detailed answer explanations, and a difficulty curve that mirrors the real exam.
Head-to-Head Comparison
| Dimension | Professor Messer | Jason Dion | |---|---|---| | Video course | Free, full coverage | Paid ($15–25 on sale), full coverage | | Teaching style | Calm, objective-by-objective | Energetic, scenario-driven | | Practice exams | $25 / 3 exams / MC only | $15–20 / 6 exams / includes PBQs | | PBQ coverage | None | Strong | | Answer explanations | Brief | Detailed with citations | | Updates | Fast | Fast | | Best for | Learning the material the first time | Validating you're exam-ready |
If both were free, the answer would still be "use both." Messer teaches better; Dion tests better. They each cover the other's weakness.
Which to Pick If You Can Only Pick One
Pick Messer alone if: you're on a strict $0 budget, you're early in your study (haven't opened a book yet), or you learn best from sequential video. You'll need to source free practice questions elsewhere and accept lower PBQ readiness.
Pick Dion alone if: you already know the material from a book, bootcamp, or job experience, and you specifically need exam-day realism. His practice exams alone can prepare a working professional in 2–3 weeks of evenings.
Use both (recommended): watch Messer's free videos for primary learning, then run Dion's practice exam pack as your final 2 weeks of readiness work. Total cost under $20, and this is the most common pattern in successful pass reports.
Common Mistakes With Each
With Messer: watching every video twice instead of using the second pass for active practice. Treating his 270-question practice set as enough.
With Dion: jumping straight to practice exams without learning the material first. Memorizing his specific questions instead of the underlying concepts (his questions are realistic but the real exam draws from a much larger pool).
Pro Tips
Buy Dion's practice exams only when Udemy is running a sale — typically $14.99. Never pay full price.
Use Messer at 1.25x for the first watch — saves 3+ hours across the course.
After every Dion practice exam, review every wrong answer with the matching Messer video.
Don't take a Dion exam more than twice — past the second attempt you're memorizing questions, not learning.
Schedule the real exam 5–7 days after you score 85%+ on a fresh Dion exam.
Common Mistakes to Avoid
Choosing one and dismissing the other based on price alone.
Buying Dion's practice exams before finishing Messer's video coverage.
Re-taking the same Dion exam 4+ times and confusing memorization with mastery.
Ignoring PBQ practice because Messer skips them.
Treating either source as a substitute for active recall (flashcards, quizzes).
The two-resource Messer + Dion stack is the most consistently recommended CompTIA prep combination on r/CompTIA for a reason: each one corrects the other's biggest weakness. If you have $15 and 60 hours, this is the highest expected pass rate per dollar in the market.
Frequently Asked Questions
Not "better" — different. Messer teaches the material better; Dion tests it better. Most successful candidates use both.
They're slightly harder, which is exactly what you want — scoring 85% on Dion typically predicts a comfortable pass.
Yes, and that's the most common pattern: Messer for video, Dion for practice exams.
$15–20 per exam pack on Udemy when on sale. Never pay full price; Udemy sales run almost weekly.
Yes — his practice exams include PBQ-style questions, which is the single biggest gap in Messer's offering.
Messer — his pacing is gentler and the free price lets you take your time. Add Dion once you've finished the video course.
Yes — free adaptive tools like PrepForCerts cover the multiple-choice side. Dion's edge is PBQ realism.
Related Resources
Free Security+ Practice Jason Dion Review Professor Messer Honest Review Professor Messer Alternatives How to Pass Security+Practice for 25+ Certifications—Free
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