# CTCAE v4.0 vs CTCAE 6 Pro

The clearest difference is rating: CTCAE 6 Pro at 5.0 against CTCAE v4.0's 3.5. CTCAE 6 Pro also leads on update cadence (monthly vs every 44 months). CTCAE v4.0's advantage is in-app purchases (none vs 2) and iOS requirement (9.2 vs 15.6). On price, ratings volume, ads and device support there is nothing between them.

Both are free to download. CTCAE 6 Pro sells 2 in-app purchases, starting at $1.99 per month. CTCAE v4.0 asks for nothing beyond the download.

CTCAE 6 Pro holds the better App Store score, 5.0 against 3.5. Both are backed by a comparable volume of ratings — 11 and 10 respectively.

CTCAE v4.0 ships an update every 44 months, CTCAE 6 Pro monthly. The most recent releases landed on October 10, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | CTCAE v4.0 | CTCAE 6 Pro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.5 (11 ratings)](https://appshunter.io/ios/app/ctcae-v40/id378487242/reviews) | **[5.0 (10 ratings)](https://appshunter.io/ios/app/ctcae-6-pro/id1625560237/reviews)** |
| Number of ratings | **11** | 10 |
| Positive reviews | 16.7% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 44 months | **Monthly** |
| Monetization | **Free** | Freemium |
| Size | 3 MB | 87 MB |
| Requires iOS | **9.2** | 15.6 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 12+ | +17 |
| Developer | [The Children's Hospital of Philadelphia](https://appshunter.io/developer/351401975) | [Koichiro Watanabe](https://appshunter.io/developer/1077985400) |

## What reviewers say

### CTCAE v4.0

[App page](https://appshunter.io/ios/app/ctcae-v40/id378487242)

This medical reference app provides a standardized system for grading the severity of adverse events related to drug treatments or medical devices. It offers hierarchical navigation, bookmarking, and search functionality for quick access to definitions and grading standards.

**Highlights:** Standardized adverse event grading system, Definitions for event severity (grades 1-5), Hierarchical navigation of categories, Bookmark frequently used events, Search across names, definitions, and grades

**Features:** macOS Compatibility

**In-app purchases:** none


### CTCAE 6 Pro

[App page](https://appshunter.io/ios/app/ctcae-6-pro/id1625560237)

Easily review and annotate medical toxicity criteria. Bookmark adverse events, search keywords, and organize entries chronologically. Offers local data storage and optional premium features for advanced note-taking and data export.

**Highlights:** Quick CTCAE 6.0 content access, Unlimited adverse event bookmarking, Keyword search with highlighting, Local data storage, Version comparison (5.0 ⇄ 6.0), Smart notes and timeline management, Spreadsheet to custom list app conversion

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Plan – Monthly | $1.99 | per month |
| Premium Plan – Annual | $9.99 | per year |


## Frequently asked questions

### Is CTCAE v4.0 free?

CTCAE v4.0 is free to download, with no in-app purchases.

### Is CTCAE 6 Pro free?

CTCAE 6 Pro is free to download, with in-app purchases available.

### Which has better reviews, CTCAE v4.0 or CTCAE 6 Pro?

CTCAE 6 Pro is rated higher. CTCAE v4.0 averages 3.5 out of 5 from 11 ratings, while CTCAE 6 Pro averages 5.0 from 10 ratings.

### Do CTCAE v4.0 or CTCAE 6 Pro have ads?

Neither CTCAE v4.0 nor CTCAE 6 Pro shows ads.

### Which is updated more often, CTCAE v4.0 or CTCAE 6 Pro?

CTCAE v4.0 ships an update every 44 months, and CTCAE 6 Pro monthly. Most recently, CTCAE v4.0 was updated on October 10, 2026 and CTCAE 6 Pro on October 21, 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.*