# 4x4 HIIT vs Stellar Intervals

The clearest difference is ads: 4x4 HIIT at none against Stellar Intervals's shown. Stellar Intervals's advantage is iOS requirement (15.1 vs 17.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

## The numbers

| Metric | 4x4 HIIT | Stellar Intervals |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | — |
| Size | 2 MB | 41 MB |
| Requires iOS | 17.0 | **15.1** |
| Devices | iPhone, Apple Watch | **iPhone, iPad, iPod** |
| Age rating | 17+ | 12+ |
| Developer | [SIA Valabijs](https://appshunter.io/developer/1853404704) | [Garage Projects AB](https://appshunter.io/developer/6774685578) |

## What reviewers say

### 4x4 HIIT

[App page](https://appshunter.io/ios/app/4x4-hiit/id6755360081)

**In-app purchases:** none


### Stellar Intervals

[App page](https://appshunter.io/ios/app/stellar-intervals/id6774685576)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is 4x4 HIIT free?

4x4 HIIT is free to download, with no in-app purchases.

### Is Stellar Intervals free?

Stellar Intervals is free to download, with no in-app purchases.

### Do 4x4 HIIT or Stellar Intervals have ads?

Stellar Intervals shows ads; 4x4 HIIT does not.

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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.*