# Diigo Browser vs QS/1 Message Center

The clearest difference is iOS requirement: QS/1 Message Center at 10.0 against Diigo Browser's 16.0. 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.

Diigo Browser ships an update every 2 weeks, QS/1 Message Center every 3 weeks. The most recent releases landed on October 11, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Diigo Browser | QS/1 Message Center |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (561 ratings)](https://appshunter.io/ios/app/diigo-browser/id933773981/reviews)** | — |
| Number of ratings | **561** | — |
| Positive reviews | 58.7% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 3 weeks |
| Monetization | Free | — |
| Size | 172 MB | 48 MB |
| Requires iOS | 16.0 | **10.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Diigo Inc.](https://appshunter.io/developer/335006603) | [RedSail Technologies, LLC](https://appshunter.io/developer/1515336618) |

## What reviewers say

### Diigo Browser

[App page](https://appshunter.io/ios/app/diigo-browser/id933773981)

Save, sync, and annotate web pages and PDFs across devices. Easily share your saved content with highlights and sticky notes. Access your bookmarks anytime, anywhere.

**Highlights:** Save and sync bookmarks, Annotate web pages with highlights, Add sticky notes to web pages, Read saved PDF files, Share bookmarks with annotations, Cross-device access

**Features:** Apple Wallet, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 💡 Useful for research and organization
- 👍 Syncs across devices
- 🚀 Efficient for bookmarking and annotating

**What reviewers complain about**

- 🐛 Buggy and crashes frequently
- 🔨 Lacking in features and functionality
- 🔍 Search and discovery issues
- 🔒 Login and sync problems

**Reported bugs**

- Login and sign-up issues
- Sync problems across devices
- Annotation and highlighting bugs
- Crashes and performance issues

**Requested features**

- Improved search and filtering
- Offline reading and caching
- Customizable organization and folders
- Better integration with other apps


### QS/1 Message Center

[App page](https://appshunter.io/ios/app/qs1-message-center/id1344865921)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Diigo Browser free?

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

### Is QS/1 Message Center free?

QS/1 Message Center is free to download, with no in-app purchases.

### Do Diigo Browser or QS/1 Message Center have ads?

Neither Diigo Browser nor QS/1 Message Center shows ads.

### Which is updated more often, Diigo Browser or QS/1 Message Center?

Diigo Browser ships an update every 2 weeks, and QS/1 Message Center every 3 weeks. Most recently, Diigo Browser was updated on October 11, 2026 and QS/1 Message Center on October 13, 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.*