# PetDiary vs Datum

The clearest difference is update cadence: Datum at every 3 days against PetDiary's every 3 weeks. PetDiary's advantage is iOS requirement (15.0 vs 26.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. PetDiary sells 3 in-app purchases, starting at $3.49 per month and Datum sells 7 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

PetDiary ships an update every 3 weeks, Datum every 3 days. The most recent releases landed on October 25, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | PetDiary | Datum |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.8 (5 ratings)](https://appshunter.io/ios/app/datum-private-data-tracker/id6784786088/reviews)** |
| Number of ratings | — | **5** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 3 days** |
| Monetization | — | Free with in-app purchases |
| Size | 79 MB | 116 MB |
| Requires iOS | **15.0** | 26.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, Mac, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Nicola Levorato](https://appshunter.io/developer/1896731593) | [EKPQA, LLC](https://appshunter.io/developer/383063546) |

## What reviewers say

### PetDiary

[App page](https://appshunter.io/ios/app/petdiary-pet-health-tracker/id6770299811)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PetDiary Pro Monthly | $3.49 | per month |
| PetDiary Pro Yearly | $20.99 | per year |
| PetDiary Pro Lifetime | $49.99 | one-time |


### Datum

[App page](https://appshunter.io/ios/app/datum-private-data-tracker/id6784786088)

This app allows you to track virtually anything, from daily habits to specific metrics, with customizable input methods and data visualization. It prioritizes user privacy by keeping all data on your device and offers extensive personalization options.

**Highlights:** Track anything with custom units, Multiple input styles (stepper, tally, dial), Bundle trackers into check-ins, Pre-made check-in templates, Customizable dashboard and charts, Attach photos, voice notes, and text, Integrates with Siri and Shortcuts

**Features:** Family Sharing, Apple Watch app

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Calculated Fields | $7.99 | one-time |
| Attachments | $7.99 | one-time |
| Automations | $7.99 | one-time |
| Unlimited Trackers | $7.99 | one-time |
| Connected Trackers | $7.99 | one-time |
| Datum Pro | $19.99 | one-time |
| Early Adopter | $49.99 | one-time |


## Frequently asked questions

### Is PetDiary free?

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

### Is Datum free?

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

### Do PetDiary or Datum have ads?

Neither PetDiary nor Datum shows ads.

### Which is updated more often, PetDiary or Datum?

PetDiary ships an update every 3 weeks, and Datum every 3 days. Most recently, PetDiary was updated on October 25, 2026 and Datum on October 28, 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.*