# PDF Compressor vs UnderLimit

The clearest difference is update cadence: UnderLimit at every 2 days against PDF Compressor's every 2 weeks. PDF Compressor's advantage is iOS requirement (13.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. PDF Compressor sells 3 in-app purchases, starting at $9.99 per 7 days and UnderLimit sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

PDF Compressor ships an update every 2 weeks, UnderLimit every 2 days. The most recent releases landed on October 31, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | PDF Compressor | UnderLimit |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 2 days** |
| Monetization | Freemium | — |
| Size | 49 MB | 4 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Amal Paul](https://appshunter.io/developer/1541483208) | [ALESSANDRO VINCENZO DEL BALZO](https://appshunter.io/developer/6813135046) |

## What reviewers say

### PDF Compressor

[App page](https://appshunter.io/ios/app/pdf-compressor-to-any-size/id6761401027)

Easily reduce PDF file sizes, split documents into separate pages, and merge multiple files into one. Offers preset compression levels or custom target sizes for your documents.

**Highlights:** Compress PDFs to any size, Split documents into pages, Merge multiple PDFs, Customizable compression levels, Offline merging and splitting, Privacy-focused file handling

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Access | $9.99 | per 7 days |
| Monthly Access | $14.99 | per month |
| Yearly Access | $39.99 | per year |


### UnderLimit

[App page](https://appshunter.io/ios/app/underlimit-pdf-compressor/id6813135044)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| UnderLimit Unlimited | $2.99 | one-time |


## Frequently asked questions

### Is PDF Compressor free?

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

### Is UnderLimit free?

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

### Do PDF Compressor or UnderLimit have ads?

Neither PDF Compressor nor UnderLimit shows ads.

### Which is updated more often, PDF Compressor or UnderLimit?

PDF Compressor ships an update every 2 weeks, and UnderLimit every 2 days. Most recently, PDF Compressor was updated on October 31, 2026 and UnderLimit on October 24, 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.*