# API Tool Pro vs OpenAPI Viewer

The clearest difference is in-app purchases: API Tool Pro at none against OpenAPI Viewer's 3. API Tool Pro also leads on update cadence (every 3 days vs every 2 weeks) and iOS requirement (12.0 vs 18.1). On price, ads and device support there is nothing between them.

Both are free to download. OpenAPI Viewer sells 3 one-off in-app purchases. API Tool Pro asks for nothing beyond the download.

API Tool Pro ships an update every 3 days, OpenAPI Viewer every 2 weeks. The most recent releases landed on September 29, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | API Tool Pro | OpenAPI Viewer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 2 weeks |
| Size | 37 MB | 13 MB |
| Requires iOS | **12.0** | 18.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [Ashen Ishanka Costha](https://appshunter.io/developer/1566497857) | [Victor Manuel Puga Ruiz](https://appshunter.io/developer/1648773908) |

## 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


### OpenAPI Viewer

[App page](https://appshunter.io/ios/app/openapi-viewer/id6761346493)

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Small Tip | $1.99 | one-time |
| Medium Tip | $4.99 | one-time |
| Large Tip | $9.99 | one-time |


## Frequently asked questions

### Is API Tool Pro free?

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

### Is OpenAPI Viewer free?

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

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

Neither API Tool Pro nor OpenAPI Viewer shows ads.

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

API Tool Pro ships an update every 3 days, and OpenAPI Viewer every 2 weeks. Most recently, API Tool Pro was updated on September 29, 2026 and OpenAPI Viewer on October 5, 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.*