# AI 4.0 | Chatbot vs Second Brain

The clearest difference is monetization model: Second Brain at freemium against AI 4.0 | Chatbot's subscription. AI 4.0 | Chatbot's advantage is update cadence (every 10 days vs every 4 weeks) and device support (4 vs 1). On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. AI 4.0 | Chatbot sells 3 in-app purchases, starting at $6.99 per 7 days and Second Brain sells 3 in-app purchases, starting at $5.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Second Brain holds the better App Store score, 4.8 against 4.6. Both are backed by a comparable volume of ratings — 130 and 61 respectively.

AI 4.0 | Chatbot ships an update every 10 days, Second Brain every 4 weeks. The most recent releases landed on October 21, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | AI 4.0 | Chatbot | Second Brain |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (130 ratings)](https://appshunter.io/ios/app/ai-40-chatbot/id1664402132/reviews) | **[4.8 (61 ratings)](https://appshunter.io/ios/app/second-brain-ai-chat/id6446254904/reviews)** |
| Number of ratings | **130** | 61 |
| Positive reviews | 36.4% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 4 weeks |
| Monetization | Subscription | **Freemium** |
| Size | 121 MB | 78 MB |
| Requires iOS | **15** | 16.6 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone |
| Age rating | 17+ | 17+ |
| Developer | [CODEPAD YAZILIM VE DIJITAL HIZMETLER LIMITED SIRKETI](https://appshunter.io/developer/907140692) | [Tairs Rzajevs](https://appshunter.io/developer/1576119083) |

## What reviewers say

### AI 4.0 | Chatbot

[App page](https://appshunter.io/ios/app/ai-40-chatbot/id1664402132)

This AI-powered assistant simulates human conversation using advanced natural language processing. It can understand and respond to a wide range of inquiries, offering quick and efficient assistance for tasks like information retrieval and customer service. The app is designed for seamless integration into various platforms.

**Highlights:** Simulates human conversation, Natural language processing, Machine learning techniques, Vast text data training, Information retrieval, Customer service support, Language translation

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Weekly \| Pro | $6.99 | per 7 days |
| Monthly Premium  \| Pro | $14.99 | per month |
| Yearly Premium  \| Pro | $39.99 | per year |


### Second Brain

[App page](https://appshunter.io/ios/app/second-brain-ai-chat/id6446254904)

This AI chatbot uses GPT technology to generate creative content like stories and songs, answer questions, and provide entertainment. It offers a premium subscription for enhanced features and a free trial period.

**Highlights:** AI-powered writing assistance, Story and song generation, Question answering, Joke telling, GPT technology integration

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium for one Week | $5.99 | per 7 days |
| Premium for one Month | $9.99 | per month |
| Premium for one Year | $39.99 | per year |


## Frequently asked questions

### Is AI 4.0 | Chatbot free?

AI 4.0 | Chatbot is free to download, with in-app purchases available.

### Is Second Brain free?

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

### Which has better reviews, AI 4.0 | Chatbot or Second Brain?

Second Brain is rated higher. AI 4.0 | Chatbot averages 4.6 out of 5 from 130 ratings, while Second Brain averages 4.8 from 61 ratings.

### Do AI 4.0 | Chatbot or Second Brain have ads?

Neither AI 4.0 | Chatbot nor Second Brain shows ads.

### Which is updated more often, AI 4.0 | Chatbot or Second Brain?

AI 4.0 | Chatbot ships an update every 10 days, and Second Brain every 4 weeks. Most recently, AI 4.0 | Chatbot was updated on October 21, 2026 and Second Brain on October 24, 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.*