# HTML Viewer Pro vs Chemcalc

The clearest difference is ads: Chemcalc at none against HTML Viewer Pro's shown. Chemcalc also leads on update cadence (fortnightly vs every 15 months). HTML Viewer Pro's advantage is iOS requirement (12.0 vs 15.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. HTML Viewer Pro sells 2 in-app purchases, starting at $1.99 per month and Chemcalc sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

HTML Viewer Pro ships an update every 15 months, Chemcalc fortnightly. The most recent releases landed on October 24, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | HTML Viewer Pro | Chemcalc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.9 (45 ratings)](https://appshunter.io/ios/app/html-viewer-pro/id1521187909/reviews)** | — |
| Number of ratings | **45** | — |
| Positive reviews | 49.1% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 15 months | **Fortnightly** |
| Monetization | Free with in-app purchases | — |
| Size | 33 MB | 54 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Hayato Shimizu](https://appshunter.io/developer/1207195348) | [F-JAP INDUSTRIES LIMITED](https://appshunter.io/developer/1866287681) |

## What reviewers say

### HTML Viewer Pro

[App page](https://appshunter.io/ios/app/html-viewer-pro/id1521187909)

View HTML source code from URLs or directly from Safari. This app offers multi-tab browsing, bookmarking, and search functionality. Customize the display with various themes, fonts, and user agents.

**Highlights:** View source code from URLs, View source code from Safari share, Multi-tab browsing, Bookmark and history management, Keyword search in source code, Switch between static and dynamic HTML, Customizable themes and fonts

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium (Monthly plan) | $1.99 | per month |
| Premium (Buying out) | $19.99 | one-time |


### Chemcalc

[App page](https://appshunter.io/ios/app/chemcalc/id6761749275)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Ad removal | $9.99 | one-time |


## Frequently asked questions

### Is HTML Viewer Pro free?

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

### Is Chemcalc free?

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

### Do HTML Viewer Pro or Chemcalc have ads?

HTML Viewer Pro shows ads; Chemcalc does not.

### Which is updated more often, HTML Viewer Pro or Chemcalc?

HTML Viewer Pro ships an update every 15 months, and Chemcalc fortnightly. Most recently, HTML Viewer Pro was updated on October 24, 2026 and Chemcalc on October 3, 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.*