# HDI Authenticator vs Fasoo Secure Viewer

The clearest difference is update cadence: Fasoo Secure Viewer at every 6 weeks against HDI Authenticator's every 4 months. HDI Authenticator's advantage is iOS requirement (11.0 vs 15.0). On price, ads, 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.

HDI Authenticator ships an update every 4 months, Fasoo Secure Viewer every 6 weeks. The most recent releases landed on October 7, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | HDI Authenticator | Fasoo Secure Viewer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 6 weeks** |
| Size | 22 MB | 118 MB |
| Requires iOS | **11.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [KOREAEXPERT](https://appshunter.io/developer/1161606505) | [Fasoo AI Co., Ltd.](https://appshunter.io/developer/429136974) |

## What reviewers say

### HDI Authenticator

[App page](https://appshunter.io/ios/app/hdi-authenticator/id1642884813)

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

**In-app purchases:** none


### Fasoo Secure Viewer

[App page](https://appshunter.io/ios/app/fasoo-secure-viewer/id6478472132)

**In-app purchases:** none


## Frequently asked questions

### Is HDI Authenticator free?

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

### Is Fasoo Secure Viewer free?

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

### Do HDI Authenticator or Fasoo Secure Viewer have ads?

Neither HDI Authenticator nor Fasoo Secure Viewer shows ads.

### Which is updated more often, HDI Authenticator or Fasoo Secure Viewer?

HDI Authenticator ships an update every 4 months, and Fasoo Secure Viewer every 6 weeks. Most recently, HDI Authenticator was updated on October 7, 2026 and Fasoo Secure Viewer on October 10, 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.*