# 测量工具 vs PD Meter

The clearest difference is review sentiment: 测量工具 at 84% against PD Meter's 25%. 测量工具 also leads on rating (4.5 vs 2.0) and ratings volume (77 vs 4). PD Meter's advantage is ads (none vs shown) and monetization model (free vs free with in-app purchases). On price, update cadence, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

测量工具 holds the better App Store score, 4.5 against 2.0. That said, the two scores are not equally well evidenced: 测量工具 has 77 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 84% of 测量工具's written reviews are positive against 25% of PD Meter's.

Both ship on a similar rhythm, roughly monthly. The most recent releases landed on October 26, 2026 and October 22, 2026 respectively.

## The numbers

| Metric | 测量工具 | PD Meter |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (77 ratings)](https://appshunter.io/ios/app/id1113334130/reviews)** | [2.0 (4 ratings)](https://appshunter.io/ios/app/pd-meter/id1497268134/reviews) |
| Number of ratings | **77** | 4 |
| Positive reviews | **84.0% of reviews** | 25.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Monthly | Monthly |
| Monetization | Free with in-app purchases | **Free** |
| Size | 55 MB | 93 MB |
| Requires iOS | 12.0 | **11.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [飞剑 姚](https://appshunter.io/developer/1113334129) | [杭州美戴科技有限公司](https://appshunter.io/developer/1123653009) |

## What reviewers say

### 测量工具

[App page](https://appshunter.io/ios/app/id1113334130)

This utility app offers a suite of measurement tools for your phone. It includes a ruler, protractor, noise meter, distance calculator, level, compass, and flashlight. Easily measure lengths, angles, sound levels, and more with convenient on-the-go tools.

**Highlights:** Ruler (metric/inch), Noise meter (decibel), Protractor (camera-based), Distance measurement, Level tool, Compass, Flashlight

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

**In-app purchases:** none


### PD Meter

[App page](https://appshunter.io/ios/app/pd-meter/id1497268134)

This application uses AI technology to measure interpupillary distance accurately. It offers a contactless method for measurement, avoiding close proximity required by traditional devices. Users can manually correct any AI recognition errors for precise results.

**Highlights:** AI-powered binocular interpupillary measurement, Contactless measurement method, High accuracy (0.1mm), Manual error correction, Supports FPD and NPD measurements

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is 测量工具 free?

测量工具 is free to download, with no in-app purchases.

### Is PD Meter free?

PD Meter is free to download, with no in-app purchases.

### Which has better reviews, 测量工具 or PD Meter?

测量工具 is rated higher. 测量工具 averages 4.5 out of 5 from 77 ratings, while PD Meter averages 2.0 from 4 ratings.

### Do 测量工具 or PD Meter have ads?

测量工具 shows ads; PD Meter does not.

### Which is updated more often, 测量工具 or PD Meter?

测量工具 ships an update monthly, and PD Meter monthly. Most recently, 测量工具 was updated on October 26, 2026 and PD Meter on October 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.*