# O'Reilly vs CertNinja

The clearest difference is review sentiment: CertNinja at 100% against O'Reilly's 46%. CertNinja also leads on rating (5.0 vs 4.7) and update cadence (every 5 days vs fortnightly). O'Reilly's advantage is in-app purchases (none vs 2) and ratings volume (34K vs 1). On price, ads and device support there is nothing between them.

Both are free to download. CertNinja sells 2 in-app purchases, starting at $8.99 per month. O'Reilly asks for nothing beyond the download.

CertNinja holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: O'Reilly has 34K ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 46% of O'Reilly's written reviews are positive against 100% of CertNinja's.

O'Reilly ships an update fortnightly, CertNinja every 5 days. The most recent releases landed on November 7, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | O'Reilly | CertNinja |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (34K ratings)](https://appshunter.io/ios/app/oreilly/id881697395/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/certninja-cloud-and-cyber-prep/id6771221738/reviews)** |
| Number of ratings | **34K** | 1 |
| Positive reviews | 46.5% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 5 days** |
| Monetization | **Free** | Freemium |
| Size | 65 MB | 55 MB |
| Requires iOS | 18.5 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [O'Reilly Media, Inc.](https://appshunter.io/developer/312570215) | [Saleh Rafiee](https://appshunter.io/developer/1896573168) |

## What reviewers say

### O'Reilly

[App page](https://appshunter.io/ios/app/oreilly/id881697395)

Access a vast library of tech books, videos, and courses to build in-demand skills. Stay current with the latest in programming, AI, cloud, and more. Learn on the go with offline downloads and progress syncing.

**Highlights:** Thousands of books, videos, and courses, Content on programming, AI, cloud, DevOps, cybersecurity, Audiobooks for multitasking, Live events and on-demand training, Playlists for content organization, Offline downloads and progress syncing, AI-powered search and overviews

**Features:** iMessage stickers, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 🚀 Great resource for learning
- 👍 Excellent content and library
- 💡 Helpful features like playlists
- 🚀 Offline reading and downloads

**What reviewers complain about**

- 🐛 Buggy app with crashes and issues
- 👎 Poor reading experience and navigation
- 🔒 Frequent login issues
- 👎 Inconsistent sync across devices

**Reported bugs**

- Frequent crashes and freezes
- Unreliable downloads and offline access
- Login issues and loss of progress
- Inconsistent behavior across updates

**Requested features**

- Improved bookmarking and note-taking
- Customizable text formatting and layout
- Better search and content discovery
- Seamless sync across devices


### CertNinja

[App page](https://appshunter.io/ios/app/certninja-cloud-and-cyber-prep/id6771221738)

Prepare for IT certification exams with AI-powered flashcards and study tools. Access thousands of practice questions, instant explanations, and detailed progress tracking for cloud, security, and DevOps professionals.

**Highlights:** Thousands of practice questions, Instant answer explanations, AI study tutor, Progress tracking by domain, Multiple choice & multi-select questions, Covers 30+ certifications

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| CertNinja Pro | $8.99 | per month |
| CertNinja Pro Annual | $59.99 | per year |


## Frequently asked questions

### Is O'Reilly free?

O'Reilly is free to download, with no in-app purchases.

### Is CertNinja free?

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

### Which has better reviews, O'Reilly or CertNinja?

CertNinja is rated higher. O'Reilly averages 4.7 out of 5 from 34K ratings, while CertNinja averages 5.0 from 1 ratings.

### Do O'Reilly or CertNinja have ads?

Neither O'Reilly nor CertNinja shows ads.

### Which is updated more often, O'Reilly or CertNinja?

O'Reilly ships an update fortnightly, and CertNinja every 5 days. Most recently, O'Reilly was updated on November 7, 2026 and CertNinja on November 5, 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.*