# OpenLibrary Explorer vs Duodecimo

The clearest difference is ads: Duodecimo at none against OpenLibrary Explorer's shown. Duodecimo also leads on update cadence (daily vs every 8 days). OpenLibrary Explorer's advantage is iOS requirement (16.4 vs 26.0). On price, 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.

OpenLibrary Explorer ships an update every 8 days, Duodecimo daily. Both last shipped on November 6, 2026.

## The numbers

| Metric | OpenLibrary Explorer | Duodecimo |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (5 ratings)](https://appshunter.io/ios/app/duodecimo/id6824674185/reviews)** |
| Number of ratings | — | **5** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 8 days | **Daily** |
| Monetization | — | Free |
| Size | 31 MB | 532 MB |
| Requires iOS | **16.4** | 26.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 12+ |
| Developer | [Mahesh Rathi](https://appshunter.io/developer/6801780469) | [Jay Welshofer](https://appshunter.io/developer/1824870820) |

## What reviewers say

### OpenLibrary Explorer

[App page](https://appshunter.io/ios/app/openlibrary-explorer/id6807614835)

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

**In-app purchases:** none


### Duodecimo

[App page](https://appshunter.io/ios/app/duodecimo/id6824674185)

Access a vast library of 1,009 classic books for offline reading on your iPhone and iPad. Customize your reading experience with adjustable fonts, spacing, and appearance. Import additional public domain books and utilize helpful reading guides and note-taking features.

**Highlights:** 1,009 classic books included, Offline reading capability, Import from Project Gutenberg, Customizable reading interface, Searchable notes and highlights, Text-to-speech functionality, Reading progress tracking

**Features:** iPhone Duo support

**In-app purchases:** none


## Frequently asked questions

### Is OpenLibrary Explorer free?

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

### Is Duodecimo free?

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

### Do OpenLibrary Explorer or Duodecimo have ads?

OpenLibrary Explorer shows ads; Duodecimo does not.

### Which is updated more often, OpenLibrary Explorer or Duodecimo?

OpenLibrary Explorer ships an update every 8 days, and Duodecimo daily. Most recently, OpenLibrary Explorer was updated on November 6, 2026 and Duodecimo on November 6, 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.*