# PDB Viewer vs Internalize

The clearest difference is update cadence: Internalize at every 4 days against PDB Viewer's monthly. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. PDB Viewer sells 1 one-off in-app purchase and Internalize sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

PDB Viewer ships an update monthly, Internalize every 4 days. Both last shipped on October 31, 2026.

## The numbers

| Metric | PDB Viewer | Internalize |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 4 days** |
| Size | 2 MB | 10 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | iPhone, iPad | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Qvyshift LLC](https://appshunter.io/developer/1536442361) | [Trilon Apps](https://appshunter.io/developer/1563999228) |

## What reviewers say

### 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 |


### Internalize

[App page](https://appshunter.io/ios/app/internalize-ai-paper-reader/id6783331759)

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Import Credit | $4.99 | one-time |
| 5 Import Credits | $17.99 | one-time |
| 10 Import Credits | $29.99 | one-time |


## Frequently asked questions

### Is PDB Viewer free?

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

### Is Internalize free?

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

### Do PDB Viewer or Internalize have ads?

Neither PDB Viewer nor Internalize shows ads.

### Which is updated more often, PDB Viewer or Internalize?

PDB Viewer ships an update monthly, and Internalize every 4 days. Most recently, PDB Viewer was updated on October 31, 2026 and Internalize 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.*