# Sill: Remote Window Streaming for Mac to iOS Devices

Stream Mac windows to iPhone or iPad with touch and peripheral support.

- **Source:** [Hacker News (news.ycombinator.com)](https://brifing.si/source/13c923cd-6d99-442b-9b8b-1181f4d8cd91)
- **Published:** 2026-10-16
- **Topic:** [Software & Engineering](https://brifing.si/c/engineering)
- **Original article:** <https://github.com/Saffsanity/sill>
- **On Brifing:** https://brifing.si/s/c5cc1650-1790-42d6-9b73-bddae42082cc

## Remote Window Access

Sill enables users to stream specific Mac windows or the entire desktop to an iPhone or iPad. The application supports interaction via touch, trackpad, keyboard, or Apple Pencil. It functions by capturing the Mac screen, encoding it as HEVC video, and transmitting the feed to the mobile device over a network connection.

## Connectivity and Security

The system operates without external servers or accounts, prioritizing privacy. Connections are established over local networks, USB cables, or peer-to-peer Wi-Fi via Direct Wireless Connection. For remote access, users can utilize their own VPNs like Tailscale. All traffic is secured using TLS 1.3 encryption, ensuring data remains private during the streaming process.

## Hardware and Software Requirements

The host requires a Mac with Apple silicon running macOS 14 or later. Mobile devices must run iOS 17 or iPadOS 17 or later. Users must grant Screen Recording and Accessibility permissions on the Mac to allow the app to capture windows and simulate mouse or keyboard inputs for remote control functionality.

## Performance Optimization Strategy

Sill utilizes ScreenCaptureKit and the Mac's hardware video encoder for efficient performance. To maintain a real-time experience, the system prioritizes low latency over image quality. If the link or encoder falls behind, the application drops frames rather than queuing them, ensuring the displayed picture remains current with the Mac's actual state.

## Advanced Input Handling

The app translates mobile inputs into Mac mouse and keyboard events. Users can perform complex gestures like three-finger swipes for Mission Control or App Exposé. The system also supports Apple Pencil as a pointer and allows external keyboards attached to the mobile device to type directly into the active Mac window.

## Device-Specific Layouts

Sill adapts its interface based on the device. On iPhone, it provides a layout with buttons and a trackpad below the stream. For iPhone Duo, the app follows the hinge, adjusting the display layout when the device is half-open or closed. Users can also resize window text for better readability on smaller screens.

## Clipboard and Integration

The application includes a bidirectional clipboard feature, allowing text copied on a Mac to be pasted on an iOS device and vice versa. This is limited to 256 KB of text per transfer. The feature is designed to respect security, ensuring that password managers marked as concealed remain protected on the Mac.

## Virtual Display Capabilities

Sill offers a virtual display feature that moves a streamed window onto a private display space on the Mac. This ensures the window continues to update even when covered by other applications. Because this uses a private macOS API, the software is distributed via the developer's website rather than the Mac App Store.

## Open Source Development

The project is open source under the Apache License 2.0 and built using Swift and Apple frameworks. Developers can build the app from source using Xcode 27 or later. The repository includes scripts for installation and testing, encouraging community contributions while maintaining strict conventions regarding third-party dependencies and server-less architecture.

## Project Sustainability Model

Sill is provided as free software with no advertisements, tracking, or subscription fees. The developer accepts support through GitHub Sponsors to cover developer account costs. This model emphasizes a community-driven approach where features remain free for all users, focusing on utility and privacy rather than monetization through traditional software sales channels.

## Sources covering this story

- https://github.com/Saffsanity/sill — 

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_Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._
