# API Tool Pro vs STL Viewer

The clearest difference is ads: API Tool Pro at none against STL Viewer's shown. API Tool Pro also leads on iOS requirement (12.0 vs 15.0). 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.

API Tool Pro ships an update every 3 days, STL Viewer every 5 days. The most recent releases landed on October 13, 2026 and October 22, 2026 respectively.

## The numbers

| Metric | API Tool Pro | STL Viewer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Every 3 days** | Every 5 days |
| Size | 37 MB | 27 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ashen Ishanka Costha](https://appshunter.io/developer/1566497857) | [Alper Vural](https://appshunter.io/developer/1728214585) |

## What reviewers say

### API Tool Pro

[App page](https://appshunter.io/ios/app/api-tool-pro/id6749198993)

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

**In-app purchases:** none


### STL Viewer

[App page](https://appshunter.io/ios/app/stl-viewer-3d-model-and-3mf/id6801906359)

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

**In-app purchases:** none


## Frequently asked questions

### Is API Tool Pro free?

API Tool Pro is free to download, with no in-app purchases.

### Is STL Viewer free?

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

### Do API Tool Pro or STL Viewer have ads?

STL Viewer shows ads; API Tool Pro does not.

### Which is updated more often, API Tool Pro or STL Viewer?

API Tool Pro ships an update every 3 days, and STL Viewer every 5 days. Most recently, API Tool Pro was updated on October 13, 2026 and STL Viewer 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.*