# Atomic KB vs Celestis

The clearest difference is update cadence: Celestis at every 2 weeks against Atomic KB's every 2 months. Atomic KB's advantage is iOS requirement (15.0 vs 26.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Atomic KB ships an update every 2 months, Celestis every 2 weeks. Both last shipped on September 18, 2026.

## The numbers

| Metric | Atomic KB | Celestis |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (4 ratings)](https://appshunter.io/ios/app/celestis/id6781116681/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | — | Free |
| Size | 6 MB | 3.0 GB |
| Requires iOS | **15.0** | 26.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 12+ |
| Developer | [Foldspace Labs LLC](https://appshunter.io/developer/1796614941) | [Celestis Ai Inc](https://appshunter.io/developer/6781116683) |

## What reviewers say

### Atomic KB

[App page](https://appshunter.io/ios/app/atomic-kb/id6759266634)

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

**In-app purchases:** none


### Celestis

[App page](https://appshunter.io/ios/app/celestis/id6781116681)

This AI assistant empowers professionals with private, on-device intelligence for document analysis and knowledge retrieval. It offers offline capabilities, custom AI models built from your data, and supports various AI providers for ultimate flexibility and data sovereignty.

**Highlights:** On-device AI with Apple Intelligence, Offline AI capabilities, Private Capsules for custom AI models, Support for multiple AI providers, Near 100% accurate, sourceable answers, Document ingestion from various formats

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Atomic KB free?

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

### Is Celestis free?

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

### Do Atomic KB or Celestis have ads?

Neither Atomic KB nor Celestis shows ads.

### Which is updated more often, Atomic KB or Celestis?

Atomic KB ships an update every 2 months, and Celestis every 2 weeks. Most recently, Atomic KB was updated on September 18, 2026 and Celestis on September 18, 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.*