Live screen and system audio
To any browser on the same network. No app, no account, no cloud.
Open-source Mac app
Mac Screencast
Your Mac screen, on any screen in the house.
Broadcast your Mac screen, with system audio, to any browser on your Wi-Fi: laptops, phones, or a Fire TV. Free, open source, nothing to install on the viewing device.
- macOS
- Open source
- Electron
- MIT
What it does
Mac Screencast turns your Mac into a small local broadcaster. Click Start, open the watch URL on any device on the same Wi-Fi, and the screen plays a few seconds behind live, with sound. It runs entirely on your own network: no app on the TV, no account, no cloud.
Fire TV friendly
Works in the Silk browser and can be controlled with the TV remote.
Buffered playback
A few seconds behind live for smoothness, with an automatic plain-HTTP fallback for browsers where MediaSource will not attach.
Movie mode
Serve an MP4 directly to viewers: full quality, seekable, with sound.
An honest status line
“Broadcasting with sound · 1 watching · 2.5 Mb/s” means data is genuinely flowing.
Install on your Mac
- 1Download the latest Mac Screencast .dmg from the Releases page.
- 2Open the .dmg and drag Mac Screencast into Applications.
- 3First launch only: right-click the app and choose Open. The build is unsigned, so macOS asks once.
- 4Click Start Broadcasting, grant the Screen Recording permission, then quit and reopen the app once.
Requirements
macOS on Apple Silicon. Node.js 18 or newer only if you run it from source.
Works with
Fire TV (Silk browser), Android TV and Google TV (any browser app), smart TVs with a browser, Xbox (Edge), and every phone, tablet or laptop on the same Wi-Fi.
How it works
Screen and system-audio capture, encoded with WebCodecs (H.264/AAC) into fragmented MP4, fanned out by a tiny local server to viewers over WebSockets, with a plain-HTTP fallback. Viewers can join and leave freely without interrupting each other.
License
MIT licensed. Issues and pull requests are welcome.
Your Mac screen, on any screen in the house.
Broadcast your Mac screen, with system audio, to any browser on your Wi-Fi: laptops, phones, or a Fire TV. Free, open source, nothing to install on the viewing device.