# うみびん vs OnceChat

The clearest difference is ads: OnceChat at none against うみびん's shown. OnceChat also leads on iOS requirement (15.1 vs 17.6). うみびん's advantage is update cadence (daily vs every 2 weeks). On price, 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.

うみびん ships an update daily, OnceChat every 2 weeks. The most recent releases landed on October 8, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | うみびん | OnceChat |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | **Daily** | Every 2 weeks |
| Size | 100 MB | 37 MB |
| Requires iOS | 17.6 | **15.1** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Akito Ikeshita](https://appshunter.io/developer/1884315193) | [Kosei Takanashi](https://appshunter.io/developer/6777430042) |

## What reviewers say

### うみびん

[App page](https://appshunter.io/ios/app/umibin/id6760686115)

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

**In-app purchases:** none


### OnceChat

[App page](https://appshunter.io/ios/app/oncechat/id6777430040)

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

**In-app purchases:** none


## Frequently asked questions

### Is うみびん free?

うみびん is free to download, with no in-app purchases.

### Is OnceChat free?

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

### Do うみびん or OnceChat have ads?

うみびん shows ads; OnceChat does not.

### Which is updated more often, うみびん or OnceChat?

うみびん ships an update daily, and OnceChat every 2 weeks. Most recently, うみびん was updated on October 8, 2026 and OnceChat on October 6, 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.*