# PDF Size Reducer & Compressor vs UnderMB

The clearest difference is in-app purchases: UnderMB at none against PDF Size Reducer & Compressor's 2. UnderMB also leads on update cadence (every 11 days vs every 3 weeks) and iOS requirement (15.0 vs 17.0). PDF Size Reducer & Compressor's advantage is ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. PDF Size Reducer & Compressor sells 2 in-app purchases, starting at $2.99 per 7 days. UnderMB asks for nothing beyond the download.

PDF Size Reducer & Compressor ships an update every 3 weeks, UnderMB every 11 days. The most recent releases landed on November 9, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | PDF Size Reducer & Compressor | UnderMB |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/undermb-file-size-compressor/id6811049521/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 3 weeks | **Every 11 days** |
| Monetization | — | Ad-supported |
| Size | 10 MB | 9 MB |
| Requires iOS | 17.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Baris Mustafa Han Unlu](https://appshunter.io/developer/1852272455) | [CEMRE SIMSEK](https://appshunter.io/developer/6801148028) |

## What reviewers say

### PDF Size Reducer & Compressor

[App page](https://appshunter.io/ios/app/pdf-size-reducer-and-compressor/id6758089930)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PDF Compress | $2.99 | per 7 days |
| Smart Compression | $5.99 | per month |


### UnderMB

[App page](https://appshunter.io/ios/app/undermb-file-size-compressor/id6811049521)

Reduce the size of photos, videos, audio, and PDFs on your device. Select a target file size or use presets for common uploads like email or chat apps. Preview your compressed files before saving or sharing, with optional metadata removal.

**Highlights:** Compress images, videos, audio, and PDFs, Choose target file size (KB/MB), Built-in presets for uploads, Preview before saving, Optional metadata removal, Batch processing

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

**In-app purchases:** none


## Frequently asked questions

### Is PDF Size Reducer & Compressor free?

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

### Is UnderMB free?

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

### Do PDF Size Reducer & Compressor or UnderMB have ads?

UnderMB shows ads; PDF Size Reducer & Compressor does not.

### Which is updated more often, PDF Size Reducer & Compressor or UnderMB?

PDF Size Reducer & Compressor ships an update every 3 weeks, and UnderMB every 11 days. Most recently, PDF Size Reducer & Compressor was updated on November 9, 2026 and UnderMB on October 31, 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.*