# Units vs PDF Vault

The clearest difference is update cadence: PDF Vault at fortnightly against Units's every 5 weeks. Units's advantage is iOS requirement (15.0 vs 18.1). On price, review sentiment, ads and in-app purchases there is nothing between them.

Both are free to download. Units sells 3 in-app purchases, starting at $0.99 per month and PDF Vault sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

Units ships an update every 5 weeks, PDF Vault fortnightly. The most recent releases landed on October 11, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | Units | PDF Vault |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (261 ratings)](https://appshunter.io/ios/app/units-unit-converter/id1527329982/reviews)** | — |
| Number of ratings | **261** | — |
| Positive reviews | 45.5% of reviews | **50.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Fortnightly** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 3 MB | 4 MB |
| Requires iOS | **15.0** | 18.1 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [Andreas Maier](https://appshunter.io/developer/454364359) | [Dmytro Skorokhod](https://appshunter.io/developer/994177751) |

## What reviewers say

### Units

[App page](https://appshunter.io/ios/app/units-unit-converter/id1527329982)

Easily convert between a wide range of measurement units and currencies. Features a clear and simple interface for quick conversions of length, mass, volume, speed, and more. Supports popular currencies and common units for everyday use.

**Highlights:** Extensive unit conversions, Multiple currency support, Easy and clear handling, Converts length, mass, volume, Supports speed, area, pressure, Converts time and temperature

**Features:** Family Sharing, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $0.99 | per month |
| Yearly | $4.99 | per year |
| One time purchase | $9.99 | one-time |


### PDF Vault

[App page](https://appshunter.io/ios/app/pdf-vault-document-app/id1599303874)

This ultra-lightweight application offers a comprehensive suite of PDF tools, including text-to-speech functionality, digital signing, document scanning, organization, and instant translation. It's designed for efficiency and ease of use, saving device space while enhancing productivity for work, study, or personal tasks.

**Highlights:** Text-to-speech for PDFs, Digital document signing, Scan paper documents to PDF, Organize and manage PDF files, Instant document translation, Ultra-lightweight and fast

**Features:** Family Sharing, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Mox PDF Tool Unlimited Monthly | $4.99 | per month |
| Mox PDF Tool Unlimited Annually | $19.99 | per year |


## Frequently asked questions

### Is Units free?

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

### Is PDF Vault free?

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

### Do Units or PDF Vault have ads?

Neither Units nor PDF Vault shows ads.

### Which is updated more often, Units or PDF Vault?

Units ships an update every 5 weeks, and PDF Vault fortnightly. Most recently, Units was updated on October 11, 2026 and PDF Vault on October 12, 2026.

---

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