# AI Viewer vs Nitro PDF Pro

The clearest difference is rating: Nitro PDF Pro at 3.9 against AI Viewer's 2.9. Nitro PDF Pro also leads on ads (none vs shown) and ratings volume (161 vs 14). AI Viewer's advantage is update cadence (fortnightly vs every 2 months) and review sentiment (29% vs 13%). On price, in-app purchases, monetization model and device support there is nothing between them.

Both are free to download. AI Viewer sells 1 in-app purchase, starting at $24.99 per year and Nitro PDF Pro sells 2 in-app purchases, starting at $19.99 per year. Whichever you choose, the download price is not the number that matters.

Nitro PDF Pro holds the better App Store score, 3.9 against 2.9. That said, the two scores are not equally well evidenced: Nitro PDF Pro has 161 ratings behind it against 14, so its average is the more settled of the two. Written reviews complicate that: 29% of AI Viewer's written reviews are positive against 13% of Nitro PDF Pro's, so the app with the better star average is not the one people write more warmly about.

AI Viewer ships an update fortnightly, Nitro PDF Pro every 2 months. The most recent releases landed on September 21, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | AI Viewer | Nitro PDF Pro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.9 (14 ratings)](https://appshunter.io/ios/app/ai-viewer/id1505083223/reviews) | **[3.9 (161 ratings)](https://appshunter.io/ios/app/nitro-pdf-pro-read-and-edit/id1608616539/reviews)** |
| Number of ratings | 14 | **161** |
| Positive reviews | **28.6% of reviews** | 12.5% of reviews |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | **Fortnightly** | Every 2 months |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 19 MB | 59 MB |
| Requires iOS | **13.0** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Vaibhav Singhal](https://appshunter.io/developer/1719416463) | [Nitro Software, Inc.](https://appshunter.io/developer/1607870122) |

## What reviewers say

### AI Viewer

[App page](https://appshunter.io/ios/app/ai-viewer/id1505083223)

View Adobe Illustrator (.ai) files on your mobile device without needing a license. Convert .ai files to PDF or PNG, zoom in on previews, and easily locate Illustrator files stored on your device.

**Highlights:** Preview .ai files, Save as PDF or PNG, List all .ai files on device, Pinch to zoom, Remove ads permanently, Contact support

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Yearly Subscription | $24.99 | per year |


### Nitro PDF Pro

[App page](https://appshunter.io/ios/app/nitro-pdf-pro-read-and-edit/id1608616539)

Edit, read, sign, and secure PDF documents on your iOS device. This powerful yet lightweight app allows for on-the-go productivity with features like text editing, annotation, form filling, and cloud syncing.

**Highlights:** Edit PDF text, Annotate and highlight PDFs, Fill and save PDF forms, Sign and share PDF documents, Password protect PDFs, Sync with cloud storage, Merge and organize PDFs

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Annual Subscription | $19.99 | per year |
| Nitro PDF Pro for iOS | $9.99 | one-time |

**What reviewers like**

- 👍 Helpful for managing project documents
- 👍 Convenient for PDF modifications
- 👍 Superior PDF handling on Mac
- 👍 Satisfactory in both Mac and Windows environments

**What reviewers complain about**

- 👎 Pro features not available on iOS/iPadOS
- 👎 Yearly charges for basic features
- 👎 Expensive and useless
- 👎 Fails to deliver promised features
- 👎 Impossible to reorder PDF files

**Reported bugs**

- Cannot reorder PDF files
- Crashes when opening PDFs from websites/email
- Does not save markups or documents
- Difficulty creating new folders
- Cannot rotate pages

**Requested features**

- Keyboard support (Cmd + F for search)
- Ability to cancel search with Esc
- OCR and conversion to text documents on tablets
- User manual for iPad app
- Support for Apple Pencil


## Frequently asked questions

### Is AI Viewer free?

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

### Is Nitro PDF Pro free?

Nitro PDF Pro is free to download, with in-app purchases available.

### Which has better reviews, AI Viewer or Nitro PDF Pro?

Nitro PDF Pro is rated higher. AI Viewer averages 2.9 out of 5 from 14 ratings, while Nitro PDF Pro averages 3.9 from 161 ratings.

### Do AI Viewer or Nitro PDF Pro have ads?

AI Viewer shows ads; Nitro PDF Pro does not.

### Which is updated more often, AI Viewer or Nitro PDF Pro?

AI Viewer ships an update fortnightly, and Nitro PDF Pro every 2 months. Most recently, AI Viewer was updated on September 21, 2026 and Nitro PDF Pro on October 18, 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.*