# Eterna vs ChatPDF AI

The clearest difference is in-app purchases: Eterna at none against ChatPDF AI's 5. ChatPDF AI's advantage is update cadence (every 8 days vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

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

Eterna ships an update every 3 months, ChatPDF AI every 8 days. The most recent releases landed on September 13, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | Eterna | ChatPDF AI |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 8 days** |
| Size | 42 MB | 134 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Eterna Inc.](https://appshunter.io/developer/1500225556) | [nimet oz](https://appshunter.io/developer/1861573318) |

## What reviewers say

### Eterna

[App page](https://appshunter.io/ios/app/eterna/id6477453458)

**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 Eterna free?

Eterna 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 Eterna or ChatPDF AI have ads?

Neither Eterna nor ChatPDF AI shows ads.

### Which is updated more often, Eterna or ChatPDF AI?

Eterna ships an update every 3 months, and ChatPDF AI every 8 days. Most recently, Eterna was updated on September 13, 2026 and ChatPDF AI on September 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.*