# ChronoFast AI vs LeanFast

The clearest difference is ads: LeanFast at none against ChronoFast AI's shown. LeanFast also leads on update cadence (every 4 days vs every 2 weeks). ChronoFast AI's advantage is iOS requirement (17.0 vs 26.1). On price, in-app purchases and device support there is nothing between them.

Both are free to download. ChronoFast AI sells 2 in-app purchases, starting at $4.99 per month and LeanFast sells 3 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

ChronoFast AI ships an update every 2 weeks, LeanFast every 4 days. Both last shipped on October 31, 2026.

## The numbers

| Metric | ChronoFast AI | LeanFast |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/chronofast-ai/id6759078045/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 2 weeks | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 121 MB | 47 MB |
| Requires iOS | **17.0** | 26.1 |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 17+ | 12+ |
| Developer | [Soundarya Srinivas](https://appshunter.io/developer/1896661055) | [Hajer Trabelsi](https://appshunter.io/developer/6826828505) |

## What reviewers say

### ChronoFast AI

[App page](https://appshunter.io/ios/app/chronofast-ai/id6759078045)

This app acts as an AI coach for intermittent fasting, helping users understand if their food intake breaks their fast. It provides detailed metabolic insights, tracks progress, and offers social features for fasting with friends.

**Highlights:** AI-powered 'Did I Break My Fast?' analysis, Live Activity and Dynamic Island integration, Detailed metabolic stage tracking, Apple Health integration for activity and sleep, AI meal scan and barcode scanning, Social fasting features and leaderboards

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| ChronoFast-AI-Monthly-Yearly | $4.99 | per month |
| ChronoFast-AI-Monthly-Yearly | $39.99 | per year |


### LeanFast

[App page](https://appshunter.io/ios/app/leanfast-intermittent-fasting/id6818318288)

**Features:** macOS Compatibility, Family Sharing, Apple Watch app, iPhone Duo support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Prism Monthly | $3.99 | per month |
| Prism Yearly | $29.99 | per year |
| Prism Lifetime | $49.99 | one-time |


## Frequently asked questions

### Is ChronoFast AI free?

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

### Is LeanFast free?

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

### Do ChronoFast AI or LeanFast have ads?

ChronoFast AI shows ads; LeanFast does not.

### Which is updated more often, ChronoFast AI or LeanFast?

ChronoFast AI ships an update every 2 weeks, and LeanFast every 4 days. Most recently, ChronoFast AI was updated on October 31, 2026 and LeanFast on October 31, 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.*