# Astola vs Dioptra

The clearest difference is in-app purchases: Astola at none against Dioptra's 3. Astola also leads on update cadence (every 3 days vs fortnightly). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Dioptra sells 3 one-off in-app purchases. Astola asks for nothing beyond the download.

Astola ships an update every 3 days, Dioptra fortnightly. The most recent releases landed on October 29, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Astola | Dioptra |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 days** | Fortnightly |
| Size | 44 MB | 5 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Yixiong Fang](https://appshunter.io/developer/6775865845) | [Zachary Griffin](https://appshunter.io/developer/1813803229) |

## What reviewers say

### Astola

[App page](https://appshunter.io/ios/app/astola/id6798169532)

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

**In-app purchases:** none


### Dioptra

[App page](https://appshunter.io/ios/app/dioptra-glb-3d-model-viewer/id6812574588)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Small Tip | $0.99 | one-time |
| Tip | $1.99 | one-time |
| Generous Tip | $4.99 | one-time |


## Frequently asked questions

### Is Astola free?

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

### Is Dioptra free?

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

### Do Astola or Dioptra have ads?

Neither Astola nor Dioptra shows ads.

### Which is updated more often, Astola or Dioptra?

Astola ships an update every 3 days, and Dioptra fortnightly. Most recently, Astola was updated on October 29, 2026 and Dioptra on October 31, 2026.

---

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