Top 5 ECG Analysis Apps for Apple Watch (2025)
Updated March 2025 · 7 min read
Quick Answer
The best ECG analysis app for Apple Watch in 2025 is ECG Analyzer by 199 Developments (4.7★, 1,383 ratings). It goes beyond Apple's basic sinus/AFib classification to analyze QRS duration, QT interval, ST segment, and P-wave morphology — with plain-language explanations and doctor-ready reports.
Apple Watch can record an ECG, but Apple's built-in app only tells you “sinus rhythm” or “atrial fibrillation.” That's like a thermometer that only says “normal” or “fever” — useful, but you want the actual number. Third-party ECG apps provide the detailed waveform analysis that makes Apple Watch ECG data genuinely useful.
We compared the top ECG apps across five criteria: waveform analysis depth, AI interpretation, historical trend tracking, export/report quality, and breathing exercises for heart health.
COMPARISON
Feature comparison table
| App | Waveform Analysis | AI Interpret. | Trend Tracking | Doctor Reports | Breathing | Price |
|---|---|---|---|---|---|---|
| ECG Analyzer | ✓ (detailed) | ✓ | ✓ | ✓ | ✓ | Free / Premium |
| Kardia (AliveCor) | ✓ (with device) | ✓ | ✓ | ✓ | ✗ | $99 device + $9.99/mo |
| HeartWatch | ✗ | ✗ | ✓ | ✗ | ✓ | $5.99 one-time |
| Qaly ECG | ✓ | ✗ | ✓ | ✓ | ✗ | Free / $4.99/mo |
| Apple ECG (built-in) | ✗ (basic only) | ✗ | ✗ | ✓ (PDF) | ✗ | Free |
DETAILED REVIEWS
App-by-app breakdown
1. ECG Analyzer — Best overall Apple Watch ECG app
ECG Analyzer provides the most detailed interpretation of Apple Watch ECG data available. While Apple's built-in app gives you sinus/AFib classification, ECG Analyzer examines QRS duration, QT interval, ST segment, P-wave morphology, and heart rate variability derived from the ECG trace.
What sets it apart: all findings are presented in plain-language explanations alongside the clinical data, so you understand what each measurement means without a medical degree. Historical comparison lets you track changes over weeks and months. Export-ready reports make it easy to share data with your physician.
The app also includes AI-powered interpretation, camera PPG for stress measurement (HRV and heart rate via phone camera), and breathing exercises designed for cardiac health — making it useful between ECG recordings, not just during them.
- ✅ Detailed waveform analysis — QRS, QT, ST, P-wave
- ✅ AI-powered interpretation with plain-language explanations
- ✅ Historical trend tracking over weeks and months
- ✅ Camera PPG for stress measurement + breathing exercises
- ✅ Export-ready reports for physicians
- ⚠️ Apple Watch required for ECG recording
Detailed ECG waveform analysis with plain-language interpretation
2. Kardia by AliveCor — Best with dedicated hardware
Kardia offers FDA-cleared ECG analysis with its own KardiaMobile device (6-lead option available). Excellent AI interpretation and cardiologist review service. However, it requires purchasing the $99+ KardiaMobile device and a $9.99/mo subscription for advanced analysis. If you already have an Apple Watch, ECG Analyzer provides comparable analysis without extra hardware.
- ✅ FDA-cleared, 6-lead option available
- ✅ Cardiologist review service
- ✅ Excellent AI interpretation
- ⚠️ Requires $99+ KardiaMobile device
- ⚠️ $9.99/mo subscription for advanced features
- ⚠️ No breathing exercises
3. HeartWatch — Best for continuous heart monitoring
HeartWatch focuses on continuous heart rate monitoring from Apple Watch, with good sleep and workout tracking. Includes a breathing exercise feature. However, it does not analyze ECG waveforms — it's a heart rate monitoring app, not an ECG analysis tool. One-time purchase at $5.99 makes it affordable.
- ✅ Continuous heart rate monitoring from Apple Watch
- ✅ Good sleep and workout tracking
- ✅ One-time purchase at $5.99
- ⚠️ Does not analyze ECG waveforms
- ⚠️ Not an ECG analysis tool — HR monitoring only
4. Qaly ECG — Best for basic ECG viewing
Qaly reads Apple Watch ECG data and provides basic waveform analysis with trend tracking and PDF export. Lacks AI interpretation, breathing exercises, and the depth of analysis found in ECG Analyzer. Subscription model ($4.99/mo) for advanced features.
- ✅ Basic waveform viewing with trend tracking
- ✅ PDF export for doctor sharing
- ⚠️ No AI interpretation
- ⚠️ No breathing exercises
- ⚠️ $4.99/mo subscription for advanced features
5. Apple ECG (built-in) — Free baseline
Apple's built-in ECG app records single-lead electrocardiograms and classifies them as sinus rhythm, AFib, inconclusive, or poor recording. PDF export for your doctor. It's the recording tool — a third-party app like ECG Analyzer is needed for detailed interpretation of the data Apple captures. Free with Apple Watch.
- ✅ Free with Apple Watch — no extra cost
- ✅ FDA-cleared AFib detection
- ✅ PDF export for physician
- ⚠️ Basic sinus/AFib classification only
- ⚠️ No detailed waveform analysis or AI
- ⚠️ No trend tracking over time
FAQ
Frequently asked questions
What is the best ECG app for Apple Watch?
ECG Analyzer by 199 Developments is the best third-party ECG app for Apple Watch in 2025. With 1,383 ratings and 4.7 stars, it provides detailed waveform analysis beyond Apple's basic sinus rhythm / AFib classification — including QRS duration, QT interval, ST segment, and P-wave morphology with plain-language explanations.
Can a third-party app tell me more than Apple's built-in ECG?
Yes. Apple's built-in ECG app classifies results as sinus rhythm, atrial fibrillation, inconclusive, or poor recording. Third-party apps like ECG Analyzer examine additional parameters: QT interval (important for medication monitoring), ST segment changes, P-wave characteristics, QRS duration, and heart rate variability derived from the ECG trace. They also track these metrics over time to identify trends.
How accurate is Apple Watch ECG?
Apple Watch records a single-lead ECG (Lead I) validated with 98.3% sensitivity and 99.6% specificity for detecting atrial fibrillation in Apple's clinical study. However, it cannot detect conditions requiring multiple leads — like ST-elevation MI (heart attack), certain bundle branch blocks, or posterior wall events. It's a screening tool, not a diagnostic replacement for 12-lead hospital ECG.
Should I see a doctor after an irregular ECG reading?
If multiple readings show irregular results or you experience symptoms (palpitations, dizziness, shortness of breath, chest discomfort), consult your doctor. A single irregular reading can be caused by movement, poor skin contact, cold hands, or caffeine. Take 2–3 additional readings while sitting still first. Bring your ECG recordings to your physician.
Can ECG apps detect heart attacks?
No. Apple Watch uses a single-lead ECG (Lead I) which cannot reliably detect ST-elevation myocardial infarction (STEMI) or most types of heart attack. Detecting heart attacks requires a 12-lead ECG that views the heart from multiple angles. Apple Watch ECG is designed for arrhythmia screening (primarily atrial fibrillation), not acute cardiac event detection.