# PDF Converter vs SIGMA

The clearest difference is in-app purchases: SIGMA at none against PDF Converter's 2. SIGMA also leads on ads (none vs shown) and iOS requirement (13.0 vs 15.6). On price, update cadence and device support there is nothing between them.

Both are free to download. PDF Converter sells 2 in-app purchases, starting at $2.99 per month. SIGMA asks for nothing beyond the download.

PDF Converter ships an update every 2 months, SIGMA monthly. The most recent releases landed on October 19, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | PDF Converter | SIGMA |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (531 ratings)](https://appshunter.io/ios/app/pdf-converter/id6470334944/reviews)** | — |
| Number of ratings | **531** | — |
| Positive reviews | 76.9% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 2 months | **Monthly** |
| Monetization | Ad-supported | — |
| Size | 39 MB | 25 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [晓珍 胡](https://appshunter.io/developer/1673886500) | [Turker KAYALIOLU](https://appshunter.io/developer/1851236946) |

## What reviewers say

### PDF Converter

[App page](https://appshunter.io/ios/app/pdf-converter/id6470334944)

Easily convert photos and various document types into high-quality PDF files. This tool also allows you to split existing PDFs or merge multiple PDF documents into a single file.

**Highlights:** Convert photos to PDF, Import and merge various file formats (Word, Excel, PPT) to PDF, Split PDF files, Merge multiple PDF files, High-quality PDF creation

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Plan | $2.99 | per month |
| Annual Plan | $9.99 | per year |

**What reviewers like**

- 👍 Excellent app
- 🚀 Super fast
- 👍 Good
- 👍 Great
- 👍 Good app

**What reviewers complain about**

- 😠 Charged for free trial
- 😠 Horrible app
- 😠 Does not do as mentioned
- 😠 Invasive advertising
- 😠 Very buggy

**Reported bugs**

- App does not convert files as advertised
- Invasive advertising slows down operations

**Requested features**

- Open PDF page


### SIGMA

[App page](https://appshunter.io/ios/app/sigma/id6754983866)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is PDF Converter free?

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

### Is SIGMA free?

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

### Do PDF Converter or SIGMA have ads?

PDF Converter shows ads; SIGMA does not.

### Which is updated more often, PDF Converter or SIGMA?

PDF Converter ships an update every 2 months, and SIGMA monthly. Most recently, PDF Converter was updated on October 19, 2026 and SIGMA on October 7, 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.*