# OSS vs Java SE 21 Developer

The clearest difference is price: Java SE 21 Developer at Free against OSS's $3.99. Java SE 21 Developer also leads on update cadence (weekly vs every 15 months). OSS's advantage is in-app purchases (none vs 1). On ads, device support and iOS requirement there is nothing between them.

Java SE 21 Developer is free to download; OSS costs $3.99 up front. Java SE 21 Developer sells 1 one-off in-app purchase. OSS asks for nothing beyond the download.

OSS ships an update every 15 months, Java SE 21 Developer weekly. The most recent releases landed on November 5, 2026 and November 13, 2026 respectively.

## The numbers

| Metric | OSS | Java SE 21 Developer |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 15 months | **Weekly** |
| Size | 44 MB | 233 MB |
| Requires iOS | 15.1 | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Daisuke Matsubara](https://appshunter.io/developer/1720755722) | [CHOI SEONGMIN](https://appshunter.io/developer/6772332527) |

## What reviewers say

### OSS

[App page](https://appshunter.io/ios/app/oss-db-silver/id6745166641)

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

**In-app purchases:** none


### Java SE 21 Developer

[App page](https://appshunter.io/ios/app/java-se-21-developer/id6785110070)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Access | $4.99 | one-time |


## Frequently asked questions

### Is OSS free?

OSS costs $3.99, with no in-app purchases.

### Is Java SE 21 Developer free?

Java SE 21 Developer is free to download, with in-app purchases available.

### Do OSS or Java SE 21 Developer have ads?

Neither OSS nor Java SE 21 Developer shows ads.

### Which is updated more often, OSS or Java SE 21 Developer?

OSS ships an update every 15 months, and Java SE 21 Developer weekly. Most recently, OSS was updated on November 5, 2026 and Java SE 21 Developer on November 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.*