# cDoc vs PreVision

The clearest difference is update cadence: cDoc at every 6 weeks against PreVision's every 7 months. 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.

cDoc ships an update every 6 weeks, PreVision every 7 months. The most recent releases landed on September 10, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | cDoc | PreVision |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 7 months |
| Size | 129 MB | 58 MB |
| Requires iOS | 12.2 | **11.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Chemical Documentation cDoc AB](https://appshunter.io/developer/1190862631) | [Presto Brandsäkerhet](https://appshunter.io/developer/1388983668) |

## What reviewers say

### cDoc

[App page](https://appshunter.io/ios/app/cdoc/id1190862632)

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

**In-app purchases:** none


### PreVision

[App page](https://appshunter.io/ios/app/prevision/id1388983669)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is cDoc free?

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

### Is PreVision free?

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

### Do cDoc or PreVision have ads?

Neither cDoc nor PreVision shows ads.

### Which is updated more often, cDoc or PreVision?

cDoc ships an update every 6 weeks, and PreVision every 7 months. Most recently, cDoc was updated on September 10, 2026 and PreVision on September 16, 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.*