# Protein Sequence Viewer vs PDB Viewer

The clearest difference is in-app purchases: Protein Sequence Viewer at none against PDB Viewer's 1. Protein Sequence Viewer also leads on update cadence (every 2 days vs monthly) and iOS requirement (13.0 vs 16.0). PDB Viewer's advantage is ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. PDB Viewer sells 1 one-off in-app purchase. Protein Sequence Viewer asks for nothing beyond the download.

Protein Sequence Viewer ships an update every 2 days, PDB Viewer monthly. The most recent releases landed on October 5, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | Protein Sequence Viewer | PDB Viewer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 2 days** | Monthly |
| Size | 25 MB | 2 MB |
| Requires iOS | **13.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Kazunari Sasaki](https://appshunter.io/developer/1857860050) | [Qvyshift LLC](https://appshunter.io/developer/1536442361) |

## What reviewers say

### Protein Sequence Viewer

[App page](https://appshunter.io/ios/app/protein-sequence-viewer/id6758012449)

**Features:** macOS Compatibility

**In-app purchases:** none


### PDB Viewer

[App page](https://appshunter.io/ios/app/pdb-viewer-3d-molecules/id6777468488)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PDB Viewer Pro | $9.99 | one-time |


## Frequently asked questions

### Is Protein Sequence Viewer free?

Protein Sequence Viewer is free to download, with no in-app purchases.

### Is PDB Viewer free?

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

### Do Protein Sequence Viewer or PDB Viewer have ads?

Protein Sequence Viewer shows ads; PDB Viewer does not.

### Which is updated more often, Protein Sequence Viewer or PDB Viewer?

Protein Sequence Viewer ships an update every 2 days, and PDB Viewer monthly. Most recently, Protein Sequence Viewer was updated on October 5, 2026 and PDB Viewer on October 16, 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.*