# PD+ vs Haibi

The clearest difference is update cadence: Haibi at every 4 days against PD+'s every 2 months. Haibi also leads on iOS requirement (15.1 vs 17.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. PD+ sells 1 one-off in-app purchase and Haibi sells 2 in-app purchases, starting at $8.99 per month. Whichever you choose, the download price is not the number that matters.

PD+ ships an update every 2 months, Haibi every 4 days. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | PD+ | Haibi |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (557 ratings)](https://appshunter.io/ios/app/pd-plus-easy-pupillary-distance/id1560353383/reviews)** | — |
| Number of ratings | **557** | — |
| Positive reviews | 54.2% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 76 MB | 108 MB |
| Requires iOS | 17.6 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [Zernike LLC](https://appshunter.io/developer/1636196510) | [Zachary Kent Reynolds](https://appshunter.io/developer/1795254426) |

## What reviewers say

### PD+

[App page](https://appshunter.io/ios/app/pd-plus-easy-pupillary-distance/id1560353383)

This app measures pupillary distance (PD) and fitting heights using your device's camera. It offers various optical calculators for lens adjustments and acuity estimations. Accurate measurements are crucial for optimal lens centering and multifocal lens positioning.

**Highlights:** Pupillary distance measurement, Fitting height measurement, Binocular and monocular PD, Rx transposition calculator, Vertex adjustment calculator, Crossed cylinders calculator, Minimum blank size calculator

**Features:** Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Subscription | $7.99 | one-time |

**What reviewers like**

- 👍 Easy and quick measurement
- 💡 Clever and innovative app
- ⭐ Highly accurate measurements
- 👍 Friendly and easy to use
- 🗣️ Voice instructions included

**What reviewers complain about**

- 📉 Unstable measurements
- ❓ Measurement inconsistency
- ❌ Inaccurate PD readings
- 🤔 Measurements not trustworthy
- 📏 PD off by several mm

**Reported bugs**

- Face size unstable
- Camera distance sensitive
- App keeps crashing
- PD feature doesn't work on iPad
- Page stays black on iPad

**Requested features**

- Can this app measure the PD for progressive lenses for right and left eyes?


### Haibi

[App page](https://appshunter.io/ios/app/haibi/id6746136773)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Hai – Core HAIBI Access | $8.99 | per month |
| Bi – HAIBI AI + Full Access | $17.99 | per month |


## Frequently asked questions

### Is PD+ free?

PD+ is free to download, with in-app purchases available.

### Is Haibi free?

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

### Do PD+ or Haibi have ads?

Neither PD+ nor Haibi shows ads.

### Which is updated more often, PD+ or Haibi?

PD+ ships an update every 2 months, and Haibi every 4 days. Most recently, PD+ was updated on November 3, 2026 and Haibi on October 30, 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.*