Duet Display vs BetterCast: Comparing Second Monitor Apps
An in-depth comparison of Duet Display and BetterCast for using your tablet or phone as a second monitor. Pricing, performance, platform support, and more.
Duet Display has been the go-to second monitor app for years, but its shift to a subscription model has left many users looking for alternatives. BetterCast is a free, open-source option that aims to do everything Duet does — and more. Let's compare them head to head.
Pricing
This is where the two apps diverge the most.
Duet Display moved from a one-time purchase to a subscription model in recent years:
- Duet Air: $4/month
- Duet Pro: $6/month
- Annual billing available at a discount
BetterCast is completely free:
- All features included at no cost
- No subscription, no one-time purchase
- Open source under GPL 3.0
- Optional donations to support development
For users who previously paid once for Duet Display and now face recurring charges, BetterCast eliminates the cost entirely.
Platform Support
Duet Display: macOS, Windows (host); iOS, Android, Mac, Windows (client)
BetterCast: macOS, Windows, Linux (host); iOS, Android (client)
BetterCast wins here with Linux support. Duet Display doesn't support Linux hosts at all, which locks out a significant portion of developers and power users.
Performance
Duet Display uses a proprietary streaming protocol and supports both USB and wireless connections. Performance is generally good over USB but users have reported lag over wireless, particularly after macOS updates.
BetterCast uses peer-to-peer streaming over your local network with a claimed latency of 0.02ms and 60 FPS at 4K/Retina resolution. Because it connects directly between devices without relay servers, performance depends on your local network quality rather than internet connectivity.
Privacy and Data
Duet Display requires an account and uses cloud-based licensing. There have been reports of the app failing to work when Duet's servers experienced downtime, since it needs to verify your subscription.
BetterCast requires no account, no sign-up, and no internet connection. It works entirely over your local network with direct P2P connections. No data leaves your network.
Setup Experience
Duet Display: Download the app, create an account, subscribe, install on both devices, connect.
BetterCast: Download the app, install on both devices, connect. That's it — no account creation, no subscription management.
Install Size
Duet Display: Varies by platform, typically 50–100MB+
BetterCast: 3MB total install size — roughly 20–30x smaller.
Open Source vs Proprietary
Duet Display is proprietary software. You can't inspect the code, verify what data it collects, or contribute improvements.
BetterCast is open source under GPL 3.0. The entire codebase is available on GitHub. You can audit the code, submit bug reports, or contribute features.
Feature Comparison
| Feature | Duet Display | BetterCast |
|---|---|---|
| Price | $4–6/month | Free |
| Linux Support | No | Yes |
| Account Required | Yes | No |
| Internet Required | For licensing | No |
| Latency | ~16–30ms | 0.02ms |
| Max Resolution | 4K | 4K/Retina |
| Frame Rate | 60 FPS | 60 FPS |
| Install Size | 50–100MB | 3MB |
| Open Source | No | Yes |
| Apple Pencil | Yes | Coming soon |
The Verdict
Duet Display is a mature product with years of refinement, and its Apple Pencil support is a genuine advantage for creative professionals. However, its subscription pricing, account requirements, and cloud dependency are friction points.
BetterCast matches or exceeds Duet Display on performance specs while being completely free, open source, and privacy-respecting. For anyone who doesn't need Apple Pencil support, BetterCast is the clear choice.
Ready to try BetterCast?
Free, open-source, and works on every platform. Turn any device into a second monitor in under a minute.