# 4Warning vs EMF Detector

The clearest difference is review sentiment: 4Warning at 80% against EMF Detector's 25%. EMF Detector's advantage is rating (4.3 vs 1.5) and ratings volume (319 vs 2). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. 4Warning sells 1 in-app purchase, starting at $3.99 per year and EMF Detector sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

EMF Detector holds the better App Store score, 4.3 against 1.5. That said, the two scores are not equally well evidenced: EMF Detector has 319 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 80% of 4Warning's written reviews are positive against 25% of EMF Detector's, so the app with the better star average is not the one people write more warmly about.

Both ship on a similar rhythm, roughly every 2 weeks. The most recent releases landed on October 4, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | 4Warning | EMF Detector |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.5 (2 ratings)](https://appshunter.io/ios/app/4warning/id1581580861/reviews) | **[4.3 (319 ratings)](https://appshunter.io/ios/app/emf-detector-radiation-reader/id6572300713/reviews)** |
| Number of ratings | 2 | **319** |
| Positive reviews | **80.0% of reviews** | 25.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | Every 2 weeks |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 49 MB | 11 MB |
| Requires iOS | 13.2 | **13.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Paul Johnson](https://appshunter.io/developer/1581580863) | [新雨 李](https://appshunter.io/developer/1559932632) |

## What reviewers say

### 4Warning

[App page](https://appshunter.io/ios/app/4warning/id1581580861)

This location-based service alerts users within a half-mile radius of live hazards and traffic disruptions. Report incidents like accidents with text, photos, or voice messages to help others avoid delays.

**Highlights:** Location-based hazard alerts, 1/2 mile alert radius, Report road accidents, Live map with incident icons, Share text, video, photo, voice messages, Avoid traffic delays

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Yearly Plan | $3.99 | per year |


### EMF Detector

[App page](https://appshunter.io/ios/app/emf-detector-radiation-reader/id6572300713)

Transform your iPhone into an EMF detector to monitor electromagnetic fields. Identify radiation levels in various environments to assess safety at home, work, or in public spaces. Gain insights to make informed decisions about your surroundings.

**Highlights:** EMF monitoring, Electromagnetic field detection, Radiation level measurement, Environmental safety assessment, Real-time EMF readings

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| unlimited features | $4.99 | per month |
| unlimited features | $14.99 | one-time |


## Frequently asked questions

### Is 4Warning free?

4Warning is free to download, with in-app purchases available.

### Is EMF Detector free?

EMF Detector is free to download, with in-app purchases available.

### Which has better reviews, 4Warning or EMF Detector?

EMF Detector is rated higher. 4Warning averages 1.5 out of 5 from 2 ratings, while EMF Detector averages 4.3 from 319 ratings.

### Do 4Warning or EMF Detector have ads?

Neither 4Warning nor EMF Detector shows ads.

### Which is updated more often, 4Warning or EMF Detector?

4Warning ships an update every 2 weeks, and EMF Detector every 2 weeks. Most recently, 4Warning was updated on October 4, 2026 and EMF Detector on October 13, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*