Comparison

Merck Manual Professional vs VisualDx

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Merck Manual Professional

This medical reference app offers healthcare practitioners and students clear, practical explanations for thousands of conditions across major medical and surgical specialties. It includes photos, illustrations, instructional videos, drug information, quizzes, and case simulations to stay updated with the latest clinical information.

Highlights
  • Thousands of medical topics
  • Photos and illustrations
  • Instructional 'How to' videos
  • Drug reference information
  • Knowledge quizzes
  • Interactive case simulations
Features
Read full description

SPECIAL NOTE ABOUT DOWNLOAD *** Downloading this app is a 2-step process: the first step is a download of the app template, and the second step is a full download of app content. Please do not navigate away from the app until both steps have been completed. *** The amount of clinical information currently doubles every 18 months and the pace is only getting faster. Stay up-to-date with the Merck Manual Professional app. This useful medical reference app provides health care practitioners and students with clear, practical explanations for thousands of conditions in all major medical and surgical specialties. With many new features and enhancements, this app covers etiology, pathophysiology, and options for evaluation and treatment. The trusted Merck Manual Professional medical app offers: • Thousands of topics written and updated regularly by more than 350 academic physicians • Photos and Illustrations of thousands of disorders and diseases • “How to” Videos on numerous outpatient procedures and physical examinations. Concise instructional videos by medical experts on these key topics: - Casting and splinting techniques - Orthopedic examinations - Neurologic examinations - Obstetric procedures - Outpatient procedures (including IV lines, tubes, catheters, dislocation reductions and more) • Drug Reference Information* • Quizzes* check knowledge of medical disorders, symptoms, and treatments • Interactive Case Simulations* test ability to treat a specific patient over the disease course • Medical News and Commentary* covering the most current and important medical topics • Editorials* written by top medical experts *Internet access needed. About Merck Manuals Our mission is simple: We believe that health information is a universal right and that every person is entitled to accurate, accessible and usable medical information. We have a responsibility to protect, preserve and share the best current medical information to enable more informed decisions, enhance relationships between patients and professionals, and improve health care outcomes around the world. That’s why we are making the Merck Manuals available for free in digital form to professionals and patients around the world. No registration or subscription required, and no ads. NOND-1179303-0001 04/16 This mobile application is intended for Healthcare Professionals in the United States, its territories, Puerto Rico, and Canada only. For more information please read the End User License Agreement at https://www.merck.com/policy/terms-of-use/merck-apps-home.html. For more information about our privacy practices, please see our privacy commitment at https://www.msdprivacy.com To report an adverse event with a specific Merck product, please call the Merck National Service Center at 1-800-672-6372. For questions or help with the app, please contact merckmanualsinfo@merck.com

About

VisualDx

This visual reference tool aids medical professionals in improving patient engagement and diagnostic accuracy. It utilizes AI and a vast image atlas to help build custom differentials, share patient-specific images, and access comprehensive diagnostic information. Earn continuing education credits while making better medical decisions.

Highlights
  • Build custom differentials
  • Engage patients with visual aids
  • Improve diagnostic accuracy
  • Access therapy and test options
  • Recognize infectious diseases
  • Earn CME credits
Currently charting
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VisualDx is a visual reference tool for medical professionals that leverages AI technology and a comprehensive image atlas to support faster, more confident decisions, fewer unnecessary referrals and testing, and higher patient engagement and satisfaction. With VisualDx, clinicians can: • Build dynamic differentials that evolve as you think. • Use guided support to surface clinically relevant results. • Compare diagnoses to improve decisions for your patients. • Use our AI to take a picture of your patient’s skin condition to better understand morphology and possibilities. • Engage with patients by sharing pictures of skin that reflect their disease presentation. • Access therapy and testing recommendations across over 3,500 conditions. • Quickly recognize infectious diseases and travel-related illnesses with our public health resources. • Test your diagnostic skills with our image challenges and educational resources. • Earn 0.5 AMA PRA Category 1 Credits™ for internet point of care activity with every search. See why this award-winning clinical decision support system is being used in more than 2,300 hospitals, clinics, and medical schools by physicians, nurses, students, PAs, NPs, and other healthcare professionals worldwide. VisualDx requires a subscription. Terms of Use: https://www.visualdx.com/legal/acceptable-use-policy-notice Privacy Policy: https://www.visualdx.com/legal/privacy-policy/

Screenshots

Merck Manual Professional4 screens
VisualDx4 screens

Verdict

The call

The clearest difference is in-app purchases: Merck Manual Professional at none against VisualDx's 10. Merck Manual Professional also leads on rating (4.8 vs 4.4) and ratings volume (1.1K vs 186). VisualDx's advantage is update cadence (fortnightly vs every 4 months) and chart position (#24 vs unranked). On price, review sentiment, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. VisualDx sells 10 in-app purchases, starting at $39.99 per month. Merck Manual Professional asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Merck Manual Professional holds the better App Store score, 4.8 against 4.4. That said, the two scores are not equally well evidenced: Merck Manual Professional has 1.1K ratings behind it against 186, so its average is the more settled of the two. Written reviews point the same way: 92% of Merck Manual Professional's written reviews are positive against 84% of VisualDx's.

UpkeepUpdate frequency

Merck Manual Professional ships an update every 4 months, VisualDx fortnightly. Both last shipped on November 6, 2026.

Scorecard7 real differences · 4 level
Merck Manual Professional versus VisualDx: the parameters behind the verdict, then further details
ParameterMerck Manual ProfessionalVisualDx
PriceFreeFree
Rating4.8 (1.1K ratings) — better4.4 (186 ratings)
Positive reviews91.7% of reviews — better84.3% of reviews
Number of ratings1.1K — better186
Update frequencyEvery 4 monthsFortnightly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterSubscription
Best chart rank—#24 — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.0 — better16.4
Further details — not scored
Size196 MB220 MB
Age rating17+17+
DeveloperMerck & Co IncLogical Images

Customer experience

Merck Manual Professional

All ratings1,036 ratings
Positive95.1%
Neutral1.5%
Negative3.4%
Written reviews277 reviews
Positive91.7%
Neutral2.2%
Negative6.1%

VisualDx

All ratings186 ratings
Positive83.3%
Neutral4.8%
Negative11.8%
Written reviews102 reviews
Positive84.3%
Neutral1.0%
Negative14.7%

User reviews

Merck Manual Professional

From 1.1K App Store ratings

What we love

  • 💯 Excellent medical resource
  • 🔍 Comprehensive and up-to-date information
  • 🎓 Valuable for medical professionals and students
  • 🔍 Reliable and trusted source
  • 🖥️ Great offline accessibility

Room to improve

  • 🐛 App crashes and freezes
  • 🔍 Lack of search functionality
  • 🔍 Outdated or missing content
  • 🔍 Difficult navigation and organization

VisualDx

From 186 App Store ratings

What we love

  • 📸 Excellent clinical images and kodachromes
  • 👍 User-friendly interface and easy navigation
  • 🎓 Comprehensive differential diagnosis tool
  • 📚 Detailed disease summaries and treatment information
  • 🌍 Inclusive representation of skin of color

Room to improve

  • 💰 Expensive subscription cost
  • ❌ Difficult subscription cancellation process
  • 🐛 App crashes and performance issues
  • 📱 Quiz feature laggy and unreliable
  • 😤 Poor customer service responsiveness

Bugs and requests

Merck Manual Professional

Reported bugs

3 issues
  • App crashes when searching for certain conditions
  • Images and videos not loading properly
  • Offline mode not working as expected

Requested features

4 requests
  • Add personalization features like notes, highlights, and flashcards
  • Improve search functionality and relevance
  • Provide more frequent content updates
  • Enhance app stability and performance

VisualDx

Reported bugs

6 issues
  • App crashes when using quiz feature
  • CME credit claiming functionality fails
  • Subscription cancellation not processed
  • Renewal charges despite cancellation requests
  • Quiz unable to load properly
Show 1 more
  • Account access issues after payment

Requested features

6 requests
  • Make app free again (previously free)
  • Simplify subscription cancellation in-app
  • Improve quiz functionality for mobile
  • Add quiz feature to desktop version
  • Expand patient information handouts
Show 1 more
  • Better quiz image clarity and context

In-app purchases

None

Merck Manual Professional

No in-app purchases

10 purchases

VisualDx

Subscriptions9
  • Complete (1 Month)1 Month trial$39.991 Month
  • VisualDx Core Monthly7 Days trial$39.991 Month
  • Complete+DermExpert (1 Month)1 Month trial$49.991 Month
Show 6 more
  • VisualDx Elite Monthly7 Days trial$49.991 Month
  • Add DermExpert (1 Year)$99.991 Year
  • Complete (1 Year)1 Month trial$149.991 Year
  • VisualDx Core Annual7 Days trial$249.991 Year
  • VisualDx Elite Annual7 Days trial$299.991 Year
  • Complete+DermExpert (1 Year)1 Month trial$499.991 Year
One-time1
  • Complete (1 yr)$399.99

Questions

Is Merck Manual Professional free?
Merck Manual Professional is free to download, with no in-app purchases.
Is VisualDx free?
VisualDx is free to download, with in-app purchases available.
Which has better reviews, Merck Manual Professional or VisualDx?
Merck Manual Professional is rated higher. Merck Manual Professional averages 4.8 out of 5 from 1.1K ratings, while VisualDx averages 4.4 from 186 ratings.
Do Merck Manual Professional or VisualDx have ads?
Neither Merck Manual Professional nor VisualDx shows ads.
Which is updated more often, Merck Manual Professional or VisualDx?
Merck Manual Professional ships an update every 4 months, and VisualDx fortnightly. Most recently, Merck Manual Professional was updated on November 6, 2026 and VisualDx on November 6, 2026.

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