# Weight Diary vs Slim

The clearest difference is review sentiment: Weight Diary at 97% against Slim's 45%. Weight Diary also leads on rating (4.9 vs 4.1) and in-app purchases (none vs 8). Slim's advantage is price (Free vs $7.99) and update cadence (every 3 weeks vs every 6 months). On device support there is nothing between them.

Slim is free to download; Weight Diary costs $7.99 up front. Slim sells 8 in-app purchases, starting at $1.99 per month. Weight Diary asks for nothing beyond the download.

Weight Diary holds the better App Store score, 4.9 against 4.1. That said, the two scores are not equally well evidenced: Weight Diary has 2.6K ratings behind it against 74, so its average is the more settled of the two. Written reviews point the same way: 97% of Weight Diary's written reviews are positive against 45% of Slim's.

Weight Diary ships an update every 6 months, Slim every 3 weeks. Both last shipped on October 29, 2026.

## The numbers

| Metric | Weight Diary | Slim |
| --- | --- | --- |
| Price | $7.99 | **Free** |
| Rating | **[4.9 (2.6K ratings)](https://appshunter.io/ios/app/weight-diary/id410413185/reviews)** | [4.1 (74 ratings)](https://appshunter.io/ios/app/slim-weight-and-bmi-tracker/id982346439/reviews) |
| Number of ratings | **2.6K** | 74 |
| Positive reviews | **96.7% of reviews** | 44.9% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 6 months | **Every 3 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Best chart rank | **#84** | — |
| Size | 11 MB | 24 MB |
| Requires iOS | 26.0 | **11.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [CURLYBRACE APPS LTD](https://appshunter.io/developer/410413205) | [2Hearts IT-Solutions](https://appshunter.io/developer/1716165123) |

## What reviewers say

### Weight Diary

[App page](https://appshunter.io/ios/app/weight-diary/id410413185)

**Currently charting:** #84 Top Paid · Health & Fitness (US App Store)

Track your weight loss journey with a clear trend line to visualize progress. Log daily weights, estimate loss rates, and plan for your goals. Supports custom start dates and integrates with health platforms.

**Highlights:** Daily weight logging, Clear trend line visualization, Progress and goal tracking, Custom start date setting, Apple Health and scale sync, BMI and calorie calculators, Data backup and export

**In-app purchases:** none


### Slim

[App page](https://appshunter.io/ios/app/slim-weight-and-bmi-tracker/id982346439)

Track your weight and BMI with a beautiful interface. Set goals, receive reminders, and unlock rewards on your journey to a healthier you. Seamlessly syncs with Apple Health for easy data import.

**Highlights:** Track weight and BMI, Set target weight goals, Recurring reminders, Unlock rewards, Apple Health integration, Touch ID/Passcode protection

**Features:** Vision Pro support

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Slim Pro - Monthly | $1.99 | per month |
| Slim Adfree (Year) | $2.99 | per year |
| Slim Pro | $4.49 | per year |
| Slim Pro - Annual | $13.99 | per year |
| Permanently Remove Ads | $1.99 | one-time |
| Slim Pro Pack | $3.99 | one-time |
| Slim Pro | $8.99 | one-time |
| Slim Pro - Lifetime | $19.99 | one-time |


## Frequently asked questions

### Is Weight Diary free?

Weight Diary costs $7.99, with no in-app purchases.

### Is Slim free?

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

### Which has better reviews, Weight Diary or Slim?

Weight Diary is rated higher. Weight Diary averages 4.9 out of 5 from 2.6K ratings, while Slim averages 4.1 from 74 ratings.

### Do Weight Diary or Slim have ads?

Slim shows ads; Weight Diary does not.

### Which is updated more often, Weight Diary or Slim?

Weight Diary ships an update every 6 months, and Slim every 3 weeks. Most recently, Weight Diary was updated on October 29, 2026 and Slim on October 29, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*