# Compass Salt Water vs ChatPDF AI

The clearest difference is in-app purchases: Compass Salt Water at none against ChatPDF AI's 5. Compass Salt Water also leads on iOS requirement (12.0 vs 15.5). ChatPDF AI's advantage is update cadence (every 9 days vs every 4 months). On price, ads and device support there is nothing between them.

Both are free to download. ChatPDF AI sells 5 in-app purchases, starting at $4.99 per 7 days. Compass Salt Water asks for nothing beyond the download.

Compass Salt Water ships an update every 4 months, ChatPDF AI every 9 days. The most recent releases landed on October 18, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Compass Salt Water | ChatPDF AI |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 9 days** |
| Size | 61 MB | 100 MB |
| Requires iOS | **12.0** | 15.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sugar Valley SL](https://appshunter.io/developer/1261269715) | [nimet oz](https://appshunter.io/developer/1861573318) |

## What reviewers say

### Compass Salt Water

[App page](https://appshunter.io/ios/app/compass-salt-water/id6446245705)

**Features:** macOS Compatibility

**In-app purchases:** none


### ChatPDF AI

[App page](https://appshunter.io/ios/app/chatpdf-ai-chat-pdf-document/id6759845164)

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Pro | $4.99 | per 7 days |
| Weekly Pro | $6.99 | per 7 days |
| Monthly Pro | $19.99 | per month |
| Yearly Pro | $44.99 | per year |
| Yearly Pro | $89.99 | per year |


## Frequently asked questions

### Is Compass Salt Water free?

Compass Salt Water is free to download, with no in-app purchases.

### Is ChatPDF AI free?

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

### Do Compass Salt Water or ChatPDF AI have ads?

Neither Compass Salt Water nor ChatPDF AI shows ads.

### Which is updated more often, Compass Salt Water or ChatPDF AI?

Compass Salt Water ships an update every 4 months, and ChatPDF AI every 9 days. Most recently, Compass Salt Water was updated on October 18, 2026 and ChatPDF AI on October 28, 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.*