# Thorium Reader vs Calibre ebook

The clearest difference is rating: Calibre ebook at 4.7 against Thorium Reader's 3.4. Calibre ebook also leads on update cadence (every 10 days vs every 3 weeks) and iOS requirement (18.0 vs 26.1). Thorium Reader's advantage is review sentiment (40% vs 0%) and in-app purchases (none vs 3). On price, ratings volume and device support there is nothing between them.

Both are free to download. Calibre ebook sells 3 in-app purchases, starting at $4.99 per month. Thorium Reader asks for nothing beyond the download.

Calibre ebook holds the better App Store score, 4.7 against 3.4. Both are backed by a comparable volume of ratings — 12 and 11 respectively. Written reviews complicate that: 40% of Thorium Reader's written reviews are positive against 0% of Calibre ebook's, so the app with the better star average is not the one people write more warmly about.

Thorium Reader ships an update every 3 weeks, Calibre ebook every 10 days. The most recent releases landed on October 18, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Thorium Reader | Calibre ebook |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.4 (12 ratings)](https://appshunter.io/ios/app/thorium-reader/id6745025189/reviews) | **[4.7 (11 ratings)](https://appshunter.io/ios/app/calibre-ebook-pageo/id6759336810/reviews)** |
| Number of ratings | **12** | 11 |
| Positive reviews | **40.0% of reviews** | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 3 weeks | **Every 10 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 46 MB | 83 MB |
| Requires iOS | 26.1 | **18.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Readium](https://appshunter.io/developer/1232183924) | [VISIONCRAFT, SOCIEDAD LIMITADA](https://appshunter.io/developer/1473558735) |

## What reviewers say

### Thorium Reader

[App page](https://appshunter.io/ios/app/thorium-reader/id6745025189)

Organize all your ebooks, comics, and manga in a single app. Customize your reading experience with adjustable text, fonts, and themes. Listen to audiobooks and zoom into visual content with ease.

**Highlights:** Unified bookshelf for all content, Adjustable text size and spacing, Multiple font options, Text-to-speech audio playback, Zoom for comics and manga, Offline dictionary and translation, Import EPUB, PDF, CBZ files

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

**In-app purchases:** none


### Calibre ebook

[App page](https://appshunter.io/ios/app/calibre-ebook-pageo/id6759336810)

Seamlessly sync your Calibre ebook library wirelessly to your iPhone. Convert various ebook formats to EPUB directly within the app and customize your reading experience with adjustable fonts, themes, and spacing. Listen to your books with text-to-speech functionality.

**Highlights:** Wireless Calibre library sync, Built-in ebook converter (PDF, MOBI, AZW, etc. to EPUB), Customizable reading experience (fonts, themes), Text-to-speech audiobook functionality, Import from cloud storage (Files, Dropbox, iCloud), Organize library by author, series, collection

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pageo Pro | $4.99 | per month |
| Pageo Pro | $19.99 | per year |
| 1 Day of Pro | $0.99 | one-time |


## Frequently asked questions

### Is Thorium Reader free?

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

### Is Calibre ebook free?

Calibre ebook is free to download, with in-app purchases available.

### Which has better reviews, Thorium Reader or Calibre ebook?

Calibre ebook is rated higher. Thorium Reader averages 3.4 out of 5 from 12 ratings, while Calibre ebook averages 4.7 from 11 ratings.

### Do Thorium Reader or Calibre ebook have ads?

Calibre ebook shows ads; Thorium Reader does not.

### Which is updated more often, Thorium Reader or Calibre ebook?

Thorium Reader ships an update every 3 weeks, and Calibre ebook every 10 days. Most recently, Thorium Reader was updated on October 18, 2026 and Calibre ebook on October 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.*