Qaly | ECG Reader vs CarDSScan
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Qaly | ECG Reader
Get your ECGs analyzed by certified experts within minutes for peace of mind. This app supports various devices like Apple Watch and Fitbit, offering detailed interpretations of palpitations and abnormal heart rhythms. Track heart rate variability to monitor stress and recovery.
- Expert ECG interpretation
- Supports Apple Watch, Fitbit, Kardia, and more
- Analysis of 30+ heart rhythms
- Heart rate variability (HRV) tracking
- Shareable reports for doctors
- Integration with Health app
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Heart feels off? Inconclusive ECG? Get your ECGs read by certified experts within minutes, for peace of mind. 500,000+ ECGs read so far. Qaly is the leading ECG app for Apple Watch, Fitbit, Kardia, and other devices. On the Qaly app, get your ECGs reviewed by certified cardiographic technicians, trained to read ECGs for 30+ palpitations and abnormal heart rhythms like Afib, SVT, PVC, PAC, short or prolonged PR interval, short or long QT interval, WPW, and more. Track your heart rate variability (HRV) to monitor stress and recovery. The Qaly app (formerly ReadMyECG) is built by Stanford cardiologists and engineers, including Dr. Marco Perez, a Stanford Associate Professor of Medicine and Stanford Cardiac Electrophysiologist. Join 200K+ heart heroes signed-up with the Qaly app today, the only app where human experts analyze and interpret ECGs from your Apple Watch, Fitbit Watch, Withings Watch, KardiaMobile, WHOOP, Garmin or any other device within minutes, day or night. ---- Qaly members stay heart healthy: “I would like to thank everyone reading the ECGs on Qaly. Because of Qaly, I went to my doctor and was diagnosed with SVT and was told it was probably never an anxiety disorder. I have lived 15 years of hell thinking I was having intermittent panic attacks and agoraphobia. Getting set up for an ablation. I will be forever grateful.” — Marcie D. from Alabama “Qaly was so helpful in quickly identifying signs of a potentially serious heart condition … Without Qaly, I would have blown off the ECG and maybe shown it to my primary care doctor at my next appointment a few months away.” — Lori B. from Virginia “My Apple Watch categorizes my arrhythmia as normal or inconclusive, which makes me question what I’m feeling. Without Qaly, it would’ve taken me another 6 months to a year to take this to a doctor. With Qaly I gained valuable information. Qaly is the key.” — Jessi I. from Washington ----- Qaly members get peace of mind: • ECG analyzer for all watches and devices: Apple Watch ECG, Fitbit ECG, Kardia ECG, Wellue ECG, Withings ECG, WHOOP ECG, Garmin ECG, holter monitors, and more. • Borderline ECG, Inconclusive Apple Watch ECG, Inconclusive Fitbit ECG, Unclassified KardiaMobile EKG, WHOOP ECG, Garmin ECG, and all other Inconclusive ECGs analyzed within minutes, for clarity. • See irregular heartbeats like PAC and PVC on your ECG, analyzed by an expert ECG reader. • See your PR Interval, QRS Interval, and QTc Interval on your ECG, also analyzed by an expert EKG reader. • Get more from Qaly technician interpretations than your typical ECG analyzer app or HRV tracker: Qaly is the only ECG interpretation app where human experts provide professional analysis of your heart readings within minutes. • Share Qaly reports with your doctor, cardiologist, or electrophysiologist. ---- The Qaly app displays ECG data by integrating with the Health app. This is not available on the iPad. Disclaimer: Qaly does not practice medicine or provide medical services. The Qaly application and service is only for general informational and educational purposes and is in no way intended to, or be relied upon to replace or constitute professional medical care or attention by a qualified healthcare provider. The information about health provided by the Qaly application and service is not intended to diagnose, treat, cure or prevent disease. IF YOU THINK YOU HAVE A MEDICAL EMERGENCY, CALL YOUR DOCTOR OR 911 IMMEDIATELY. DO NOT RELY ON ELECTRONIC COMMUNICATIONS OR COMMUNICATION THROUGH THE QALY APPLICATION FOR IMMEDIATE, URGENT MEDICAL NEEDS. THE COMPANY SERVICE IS NOT DESIGNED OR INTENDED TO FACILITATE MEDICAL EMERGENCIES. ---- The electrocardiogram (ECG/EKG) functionality utilized by this app, available through Apple Watch and Withings devices, is accessible in regions where relevant regulatory clearances—such as FDA clearance, CE marking, UKCA marking, TGA approval, and Health Canada approval—are recognized and in effect.
CarDSScan
This app provides on-device ECG analysis using advanced AI models. It ensures privacy by processing all data locally, with no internet connection or cloud uploads required. Designed for research, it offers two distinct analysis engines for detailed signal understanding.
- On-device AI ECG analysis
- Offline processing
- ECG image capture and import
- Two AI analysis engines (ECG-Vision ATTR, ECG-GPT)
- Privacy-focused design
- Secure model downloads
- Research documentation export
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CarDSScan delivers research-grade, on-device ECG analysis from the Cardiovascular Data Science (CarDS) Lab. Built for reliability and privacy, CarDSScan runs its machine-learning models entirely on your iPhone - no internet required and no cloud uploads. Two ECG analysis engines ECG-Vision ATTR: Capture or import clear photos of printed or screen-displayed ECGs for fast, fully on-device analysis. ECG-GPT: A transformer-based ECG interpretation model designed for research-grade signal understanding. ECG-GPT runs locally on your device and may require approval for access. Private by design All inference happens locally on your device. ECG images and outputs stay with you unless you explicitly export them. Certain advanced models may be downloaded after approval. Developed by CarDS Lab Models are developed by the Cardiovascular Data Science (CarDS) Lab and have been evaluated across multi-center research datasets. CarDSScan is intended for research use only and is not a medical device. Key Features On-device ML inference (offline; no cloud processing) 12-lead ECG image capture and import ECG-Vision ATTR CNN model and ECG-GPT transformer-based model for research workflows Secure model download for approved users Clean, professional UI designed for study workflows Fast processing with reproducible outputs Optional export for research documentation Who It’s For Research teams, engineers, and clinicians conducting feasibility studies, validation work, and algorithm benchmarking in controlled settings. Privacy at a Glance No automatic data collection No ads, no trackers, no data sale Data stays on device unless you export it Requirements iPhone with camera (iOS 17.6 or later) Important CarDSScan is for research use only. It does not provide medical advice and is not intended for diagnosis or treatment. Do not make clinical decisions based on the app’s outputs.
Screenshots
Verdict
The clearest difference is ratings volume: Qaly | ECG Reader at 874 against CarDSScan's 1. Qaly | ECG Reader also leads on update cadence (every 2 weeks vs every 2 months). CarDSScan's advantage is rating (5.0 vs 4.7). On price, ads, in-app purchases and monetization model 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
CarDSScan holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Qaly | ECG Reader has 874 ratings behind it against 1, so its average is the more settled of the two.
Qaly | ECG Reader ships an update every 2 weeks, CarDSScan every 2 months. The most recent releases landed on October 25, 2026 and October 16, 2026 respectively.
| Parameter | Qaly | ECG Reader | CarDSScan |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (874 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 74.8% of reviews | — |
| Number of ratings | 874 — better | 1 |
| Update frequency | Every 2 weeks — better | Every 2 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone | iPhone |
| Requires iOS | 17.6 | 17.6 |
| Further details — not scored | ||
| Size | 94 MB | 231 MB |
| Age rating | 17+ | 17+ |
| Developer | Qaly, Inc. | Rohan Khera |
Customer experience
Qaly | ECG Reader
CarDSScan
Bugs and requests
Qaly | ECG Reader
Reported bugs
3 issues- App crashes on launch
- Issues deleting account and data
- Subscription charges not stopping after cancellation
Requested features
4 requests- Dark mode option
- Ability to view past ECG history
- Integration with more wearable devices
- Option to request a specific technician review
CarDSScan
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Qaly | ECG Reader
No in-app purchases
CarDSScan
No in-app purchases






