# Light Meter LM vs Libre Light Sensor

The clearest difference is review sentiment: Libre Light Sensor at 82% against Light Meter LM's 40%. Libre Light Sensor also leads on in-app purchases (none vs 3) and rating (4.8 vs 4.5). Light Meter LM's advantage is ratings volume (2.6K vs 113) and device support (3 vs 1). On price, update cadence, ads and iOS requirement there is nothing between them.

Both are free to download. Light Meter LM sells 3 in-app purchases, starting at $3.49 per month. Libre Light Sensor asks for nothing beyond the download.

Libre Light Sensor holds the better App Store score, 4.8 against 4.5. That said, the two scores are not equally well evidenced: Light Meter LM has 2.6K ratings behind it against 113, so its average is the more settled of the two. Written reviews point the same way: 40% of Light Meter LM's written reviews are positive against 82% of Libre Light Sensor's.

Light Meter LM ships an update monthly, Libre Light Sensor every 5 weeks. The most recent releases landed on September 23, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | Light Meter LM | Libre Light Sensor |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (2.6K ratings)](https://appshunter.io/ios/app/light-meter-lm-3000/id1554264761/reviews) | **[4.8 (113 ratings)](https://appshunter.io/ios/app/libre-light-sensor/id1644439968/reviews)** |
| Number of ratings | **2.6K** | 113 |
| Positive reviews | 40.3% of reviews | **82.4% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Monthly** | Every 5 weeks |
| Monetization | Free with in-app purchases | **Free** |
| Size | 22 MB | 1 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Lightray Innovation GmbH](https://appshunter.io/developer/1031383431) | [John Harrington](https://appshunter.io/developer/1603002572) |

## What reviewers say

### Light Meter LM

[App page](https://appshunter.io/ios/app/light-meter-lm-3000/id1554264761)

Transform your smartphone into a professional light meter. Measure illuminance and color temperature with scientifically validated accuracy, trusted by professionals. Requires a simple diffuser for precise readings.

**Highlights:** Measure illuminance (lux/foot-candle), Measure color temperature (Kelvin), Industry-leading accuracy, Pre-calibrated for your device, Low light sensitivity, Save peak reading, Custom calibration option

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Continuous Charging | $3.49 | per month |
| Single Charge | $0.99 | one-time |
| Unlimited Battery | $19.99 | one-time |

**What reviewers like**

- 👍 Great app
- 👍 Accurate measurements
- 👍 Easy to use
- 👍 Helpful customer service
- 👍 Useful for science/research

**What reviewers complain about**

- 🐛 Requires diffuser for accurate readings
- 💰 Expensive for a light meter app
- 🔋 Battery/trial period issues
- 🔍 Inconsistent/inaccurate readings
- 🙄 Misleading/deceptive marketing

**Reported bugs**

- Diffuser not recognized even when used
- App locks up/crashes
- Constant diffuser pop-up interruptions

**Requested features**

- Ability to use rear camera
- More flexible diffuser options
- Improved accuracy without diffuser


### Libre Light Sensor

[App page](https://appshunter.io/ios/app/libre-light-sensor/id1644439968)

Measure ambient light levels in Lux using your iPhone's camera. Optimize sleep quality by understanding light exposure throughout the day and night.

**Highlights:** Measure light in Lux, Utilizes iPhone camera, Optimize sleep quality, Track light exposure

**In-app purchases:** none


## Frequently asked questions

### Is Light Meter LM free?

Light Meter LM is free to download, with in-app purchases available.

### Is Libre Light Sensor free?

Libre Light Sensor is free to download, with no in-app purchases.

### Which has better reviews, Light Meter LM or Libre Light Sensor?

Libre Light Sensor is rated higher. Light Meter LM averages 4.5 out of 5 from 2.6K ratings, while Libre Light Sensor averages 4.8 from 113 ratings.

### Do Light Meter LM or Libre Light Sensor have ads?

Neither Light Meter LM nor Libre Light Sensor shows ads.

### Which is updated more often, Light Meter LM or Libre Light Sensor?

Light Meter LM ships an update monthly, and Libre Light Sensor every 5 weeks. Most recently, Light Meter LM was updated on September 23, 2026 and Libre Light Sensor on September 22, 2026.

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