# Readwise vs Project Chiron

The clearest difference is in-app purchases: Project Chiron at none against Readwise's 8. Project Chiron also leads on update cadence (every 5 days vs every 2 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Readwise sells 8 in-app purchases, starting at $4.99 per month. Project Chiron asks for nothing beyond the download.

Readwise ships an update every 2 weeks, Project Chiron every 5 days. The most recent releases landed on September 24, 2026 and September 17, 2026 respectively.

## The numbers

| Metric | Readwise | Project Chiron |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (1.5K ratings)](https://appshunter.io/ios/app/readwise/id1476885528/reviews)** | — |
| Number of ratings | **1.5K** | — |
| Positive reviews | 72.2% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 5 days** |
| Monetization | Free with in-app purchases | — |
| Size | 110 MB | 144 MB |
| Requires iOS | **15.5** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Readwise, Inc](https://appshunter.io/developer/1476885527) | [James Booth](https://appshunter.io/developer/1745107348) |

## What reviewers say

### Readwise

[App page](https://appshunter.io/ios/app/readwise/id1476885528)

This app helps you retain more of what you read by centralizing and revisiting your highlights from various reading platforms. It uses spaced repetition and active recall techniques to improve memory and offers features like tagging, note-taking, and OCR for physical books.

**Highlights:** Synchronize highlights from multiple platforms, Daily review habit via app and email, Spaced repetition and active recall, Tag, note, and search highlights, OCR for paper book highlights, Convert highlights to flashcards

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Readwise Lite Monthly | $4.99 | per month |
| Readwise Lite Monthly | $6.99 | per month |
| Readwise Full Monthly Plan | $8.99 | per month |
| Readwise Full Monthly | $12.99 | per month |
| Readwise Lite Yearly | $52.99 | per year |
| Readwise Lite Yearly | $66.99 | per year |
| Readwise Full Yearly | $94.99 | per year |
| Readwise Full Yearly | $119.99 | per year |

**What reviewers like**

- 🚀 Powerful spaced repetition
- 📚 Seamless integration with reading apps
- 🔍 Helpful AI-powered features
- 🗓️ Useful daily review routine
- 🧠 Boosts knowledge retention

**What reviewers complain about**

- 💰 Expensive subscription
- 🔌 Sync issues with some platforms
- 📱 Subpar mobile app experience
- 🕰️ Lack of flexibility in daily review
- 🔍 Limited search functionality

**Reported bugs**

- Frequent app crashes
- Sync failures with certain accounts
- Unreliable highlight capture

**Requested features**

- Add support for more reading apps
- Improve sync and import capabilities
- Introduce more customization options
- Enhance search and organization tools
- Develop a more intuitive mobile interface


### Project Chiron

[App page](https://appshunter.io/ios/app/project-chiron/id6502346822)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Readwise free?

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

### Is Project Chiron free?

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

### Do Readwise or Project Chiron have ads?

Neither Readwise nor Project Chiron shows ads.

### Which is updated more often, Readwise or Project Chiron?

Readwise ships an update every 2 weeks, and Project Chiron every 5 days. Most recently, Readwise was updated on September 24, 2026 and Project Chiron on September 17, 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.*