# Atomic KB vs SoloPDF

The clearest difference is device support: SoloPDF at 4 against Atomic KB's 2. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Atomic KB ships an update every 2 months, SoloPDF monthly. The most recent releases landed on September 18, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | Atomic KB | SoloPDF |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Monthly** |
| Size | 6 MB | 14 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Foldspace Labs LLC](https://appshunter.io/developer/1796614941) | [向东 李](https://appshunter.io/developer/1885418034) |

## What reviewers say

### Atomic KB

[App page](https://appshunter.io/ios/app/atomic-kb/id6759266634)

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

**In-app purchases:** none


### SoloPDF

[App page](https://appshunter.io/ios/app/solopdf/id6787712953)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Atomic KB free?

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

### Is SoloPDF free?

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

### Do Atomic KB or SoloPDF have ads?

Neither Atomic KB nor SoloPDF shows ads.

### Which is updated more often, Atomic KB or SoloPDF?

Atomic KB ships an update every 2 months, and SoloPDF monthly. Most recently, Atomic KB was updated on September 18, 2026 and SoloPDF on September 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.*