# Lumen vs ConstruxAi

The clearest difference is in-app purchases: Lumen at none against ConstruxAi's 2. ConstruxAi's advantage is update cadence (every 2 days vs every 2 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. ConstruxAi sells 2 in-app purchases, starting at $19.99 per month. Lumen asks for nothing beyond the download.

Lumen ships an update every 2 weeks, ConstruxAi every 2 days. The most recent releases landed on June 28, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | Lumen | ConstruxAi |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/lumen-knowledge-browser/id6762682475/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 2 days** |
| Monetization | Free | — |
| Size | 28 MB | 1 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 17+ | 4+ |
| Developer | [Daniel Kosukhin](https://appshunter.io/developer/1852657475) | [CLIFFORD MICHAEL SYNER IV](https://appshunter.io/developer/6773060029) |

## What reviewers say

### Lumen

[App page](https://appshunter.io/ios/app/lumen-knowledge-browser/id6762682475)

This app acts as a browser that remembers what you read, building a personal knowledge base from engaged pages. It allows you to ask questions in plain English about your reading history, with answers generated by an on-device AI. All your data remains private and offline.

**Highlights:** On-device AI knowledge base, Plain English questioning, Automatic content organization, Private and offline browsing, Tracker blocking, Source citation for answers

**In-app purchases:** none


### ConstruxAi

[App page](https://appshunter.io/ios/app/construxai-building-codes/id6774312310)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| ConstruxAi Pro | $19.99 | per month |
| ConstruxAi Max | $99.99 | per month |


## Frequently asked questions

### Is Lumen free?

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

### Is ConstruxAi free?

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

### Do Lumen or ConstruxAi have ads?

Neither Lumen nor ConstruxAi shows ads.

### Which is updated more often, Lumen or ConstruxAi?

Lumen ships an update every 2 weeks, and ConstruxAi every 2 days. Most recently, Lumen was updated on June 28, 2026 and ConstruxAi on September 19, 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.*