# Sleep Light Pro vs Constant Scale

The clearest difference is update cadence: Constant Scale at every 4 weeks against Sleep Light Pro's every 14 months. Sleep Light Pro's advantage is iOS requirement (8.0 vs 11.0). On price, ads, 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.

Sleep Light Pro ships an update every 14 months, Constant Scale every 4 weeks. The most recent releases landed on September 23, 2026 and September 30, 2026 respectively.

## The numbers

| Metric | Sleep Light Pro | Constant Scale |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (3 ratings)](https://appshunter.io/ios/app/sleep-light-pro/id1035640147/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 66.7% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 14 months | **Every 4 weeks** |
| Monetization | Free | — |
| Size | 26 MB | 150 MB |
| Requires iOS | **8.0** | 11.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Seligman Ventures Global Limited](https://appshunter.io/developer/1347937745) | [Yiwu Chaolan Import & Export Co., Ltd.](https://appshunter.io/developer/1788815884) |

## What reviewers say

### Sleep Light Pro

[App page](https://appshunter.io/ios/app/sleep-light-pro/id1035640147)

Drift off to sleep with calming animations and sounds designed to mimic natural light. The app gradually fades brightness and sound to match your sleep pattern, offering a simple interface and a full night clock option.

**Highlights:** Northern Light style animations, Optional relaxing sounds, Gradual fade of sound and brightness, Customizable sleep preferences, Full night clock option, Simple interface

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

**In-app purchases:** none


### Constant Scale

[App page](https://appshunter.io/ios/app/constant-scale/id6740186656)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Sleep Light Pro free?

Sleep Light Pro is free to download, with no in-app purchases.

### Is Constant Scale free?

Constant Scale is free to download, with no in-app purchases.

### Do Sleep Light Pro or Constant Scale have ads?

Neither Sleep Light Pro nor Constant Scale shows ads.

### Which is updated more often, Sleep Light Pro or Constant Scale?

Sleep Light Pro ships an update every 14 months, and Constant Scale every 4 weeks. Most recently, Sleep Light Pro was updated on September 23, 2026 and Constant Scale on September 30, 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.*