Sill is a free application that streams a Mac window or the entire desktop to an iPhone or iPad, according to its GitHub repository. Users can interact with the streamed content using touch, a trackpad, keyboard, or Apple Pencil.
The app works by having Sill for Mac capture a selected window or desktop using ScreenCaptureKit, then encode it as HEVC video using hardware video encoding before sending it over an encrypted TLS 1.3 connection. Input from the iOS device—taps, clicks, scrolls, keyboard input, and Apple Pencil movements—travels back to the Mac, where it’s converted into mouse and keyboard events.
Connection options include a local network when devices share one, a direct USB cable connection, Direct Wireless Connection for peer-to-peer Wi-Fi when no shared network exists, or a VPN like Tailscale for remote access. According to the source, there is no account or server required—connections happen directly between devices.
Sill requires a Mac with Apple silicon running macOS 14 or later, and an iPhone or iPad with iOS 17 or iPadOS 17 or later. The Mac app requests Screen Recording and Accessibility permissions, while the iOS app requests Local Network access and camera permission to scan pairing codes.
The app supports bidirectional clipboard sharing for text up to 256 KB, though password-protected items remain on the Mac. On iPhone, the streamed window appears at the top with controls below. iPad users get layouts optimized for the larger screen, with menu access in the iPad’s menu bar on iPadOS 26 or later.
For first-time use, users pair their iOS device with their Mac by scanning or typing a 12-digit code. According to the documentation, subsequent connections use stored cryptographic keys pinned to those devices. Sill for Mac remains free with no ads, tracking, or subscriptions, though optional tips support the developer through GitHub Sponsors.
The app does not play audio from the Mac and shows one window or the desktop at a time. Both the Mac and iOS app must be running for streaming to work.
Key facts
- Sill streams Mac windows or desktop to iPhone and iPad over encrypted connections
- The app supports input via touch, trackpad, keyboard, and Apple Pencil
- Connection methods include local network, USB cable, peer-to-peer Wi-Fi, or VPN
- Requires Mac with Apple silicon on macOS 14+ and iOS/iPadOS 17 or later
- The app is free with no ads, tracking, or subscription requirements