# PDF Viewer by Nutrient vs References

The clearest difference is price: PDF Viewer by Nutrient at Free against References's $4.99. PDF Viewer by Nutrient also leads on ratings volume (9.1K vs 25). References's advantage is in-app purchases (none vs 2) and rating (4.9 vs 4.6). On update cadence, ads, device support and iOS requirement there is nothing between them.

PDF Viewer by Nutrient is free to download; References costs $4.99 up front. PDF Viewer by Nutrient sells 2 in-app purchases, starting at $6.99 per 3 months. References asks for nothing beyond the download.

References holds the better App Store score, 4.9 against 4.6. That said, the two scores are not equally well evidenced: PDF Viewer by Nutrient has 9.1K ratings behind it against 25, so its average is the more settled of the two. Written reviews point the same way: 74% of PDF Viewer by Nutrient's written reviews are positive against 88% of References's.

Both ship on a similar rhythm, roughly monthly. The most recent releases landed on September 28, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | PDF Viewer by Nutrient | References |
| --- | --- | --- |
| Price | **Free** | $4.99 |
| Rating | [4.6 (9.1K ratings)](https://appshunter.io/ios/app/pdf-viewer-by-nutrient/id1120099014/reviews) | **[4.9 (25 ratings)](https://appshunter.io/ios/app/references/id1481843213/reviews)** |
| Number of ratings | **9.1K** | 25 |
| Positive reviews | 73.6% of reviews | **87.5% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Monthly | Monthly |
| Monetization | **Freemium** | Paid |
| Size | 112 MB | 55 MB |
| Requires iOS | **17.0** | 18.0 |
| Devices | iPhone, iPad, Mac, Vision Pro | iPhone, iPad, Mac, Vision Pro |
| Age rating | 4+ | 4+ |
| Developer | [PSPDFKit GmbH](https://appshunter.io/developer/966931428) | [Benjamin Burton](https://appshunter.io/developer/687735578) |

## What reviewers say

### PDF Viewer by Nutrient

[App page](https://appshunter.io/ios/app/pdf-viewer-by-nutrient/id1120099014)

Easily view, search, and annotate PDF documents on your iPhone and iPad. Import files from cloud services, fill out forms, add signatures, and organize your documents. Advanced features like redaction and combining documents are available with a Pro subscription.

**Highlights:** View and search PDFs, Annotate with highlights and notes, Sign documents digitally, Fill out PDF forms, Organize and share documents, Import from cloud services

**Features:** Family Sharing, iMessage stickers

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PDF Viewer Pro 3 Months | $6.99 | per 3 months |
| PDF Viewer Pro Yearly | $19.99 | per year |

**What reviewers like**

- 🚀 Seamless integration with iCloud and Files app
- 👍 Intuitive annotation tools with Apple Pencil
- 🎨 Versatile highlighting and drawing options
- 💾 Saves annotations to original PDF files
- 🔍 Powerful search and navigation features

**What reviewers complain about**

- 🐛 Occasional crashes and performance issues
- 🤔 Confusing UI and steep learning curve
- 🔀 Difficulty managing and organizing PDF files
- 🔍 Inconsistent text selection and highlighting
- 🔒 Privacy concerns around data collection

**Reported bugs**

- Annotations randomly disappearing or not saving
- Incompatibility issues with certain PDF files
- Scrolling and panning problems on large PDFs
- Unexpected crashes after iOS updates

**Requested features**

- Add a rubber/eraser tool for annotations
- Implement a side-by-side PDF view mode
- Improve palm rejection and gesture support
- Allow customization of toolbar and shortcuts
- Provide better options for PDF file management


### References

[App page](https://appshunter.io/ios/app/references/id1481843213)

Browse and interact with your BibTeX libraries on your mobile device. View references, follow links, and access file attachments like PDFs. Supports both classic BibTeX and BibLaTeX formats.

**Highlights:** Browse BibTeX libraries, Search references, Follow links (DOIs, URLs), View file attachments (PDFs), Supports BibLaTeX, Group by keywords

**In-app purchases:** none


## Frequently asked questions

### Is PDF Viewer by Nutrient free?

PDF Viewer by Nutrient is free to download, with in-app purchases available.

### Is References free?

References costs $4.99, with no in-app purchases.

### Which has better reviews, PDF Viewer by Nutrient or References?

References is rated higher. PDF Viewer by Nutrient averages 4.6 out of 5 from 9.1K ratings, while References averages 4.9 from 25 ratings.

### Do PDF Viewer by Nutrient or References have ads?

Neither PDF Viewer by Nutrient nor References shows ads.

### Which is updated more often, PDF Viewer by Nutrient or References?

PDF Viewer by Nutrient ships an update monthly, and References monthly. Most recently, PDF Viewer by Nutrient was updated on September 28, 2026 and References on September 23, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*