# Down4 vs OnSiren

Down4 and OnSiren are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

Down4 ships an update every 10 days, OnSiren weekly. The most recent releases landed on October 25, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Down4 | OnSiren |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 53.3% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 10 days | **Weekly** |
| Monetization | — | Free |
| Size | 93 MB | 128 MB |
| Requires iOS | **15.1** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 17+ |
| Developer | [Down4 Limited](https://appshunter.io/developer/1869393369) | [OnSiren Limited](https://appshunter.io/developer/6795174860) |

## What reviewers say

### Down4

[App page](https://appshunter.io/ios/app/down4/id6757869768)

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

**In-app purchases:** none


### OnSiren

[App page](https://appshunter.io/ios/app/onsiren/id6795977065)

This platform provides real-time shared awareness and threat intelligence for UK security officers. It briefs users on local events, allows for quick incident reporting, and offers push-to-talk communication with nearby colleagues. Membership requires a valid SIA license.

**Highlights:** Real-time threat intelligence briefings, Quick incident reporting with location, Push-to-talk communication, Shared awareness network for security officers, AI-powered local event updates

**In-app purchases:** none


## Frequently asked questions

### Is Down4 free?

Down4 is free to download, with no in-app purchases.

### Is OnSiren free?

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

### Do Down4 or OnSiren have ads?

Neither Down4 nor OnSiren shows ads.

### Which is updated more often, Down4 or OnSiren?

Down4 ships an update every 10 days, and OnSiren weekly. Most recently, Down4 was updated on October 25, 2026 and OnSiren on October 31, 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.*