This page gives a practical overview of the main TargetBridge features introduced or expanded in the 3.0 line, with links to deeper documentation where it exists.
TargetBridge supports two main display modes:
Duplicate Desktopmirrors the sender's current desktop to the receiver.Extended Desktopcreates a virtual display on the sender and streams that display to the receiver.
Extended layouts can be arranged in macOS System Settings -> Displays -> Arrange. TargetBridge remembers the saved arrangement per receiver when possible and restores it on reconnect.
When a receiver is chosen from discovery, TargetBridge stores its stable receiver identity rather than only its current IP. A Thunderbolt Bridge reconnect or a new DHCP address therefore does not make the sender forget the selected Mac.
If the receiver panel does not look correct, set the matching resolution on the TargetBridge display in macOS Display Settings. For 27-inch 5K iMac workflows, the Crisp or 5K stream profiles usually pair best with the matching HiDPI arrangement.
The Full HD profiles are for non-Retina 1080p receivers, such as every 21.5-inch
iMac that is not a Retina 4K model. They render the virtual display at 1920 × 1080
1x rather than as a HiDPI mode, so the desktop reaches the panel at its true size
and capture stays 1:1. Because those profiles already render the desktop to match
the stream, the Match render to stream toggle does not apply and is hidden when
one is selected.
Related reading:
Each session can select Automatic, H.264, or HEVC before it starts. The choice is saved per discovered receiver. Automatic remains the recommended option: it checks the receiver capability and the sender hardware encoder at the selected resolution. If a requested codec is unavailable, TargetBridge uses a compatible hardware fallback and records that choice in the log.
For non-Retina 1080p receivers, use Full HD or Full HD 60. These profiles create a 1920 × 1080 1x virtual display and avoid the double scaling that a HiDPI mode would introduce on a 1080p panel.
In a genuinely headless mirror session, where the virtual display is the only online display, TargetBridge captures that display directly. A companion audio-only ScreenCaptureKit stream keeps Audio Relay available on this path.
The Sender toolbar includes Permissions. It shows the current state of Screen Recording, Accessibility, and Input Monitoring, can request the native macOS permission prompts, and opens Privacy & Security when needed. The state refreshes after returning to TargetBridge from System Settings.
macOS deliberately requires a user to approve each permission for each installed application. The assistant streamlines that process but cannot grant or retain permission on the user's behalf. For Input Dockstation, check the required permissions on both the Sender and Receiver according to the active role.
Each sender session offers three ready-to-use display profiles before connecting:
Work 5Kcreates an extended desktop at 5K with render matching enabled.Low latencymirrors the desktop at 1440p and 60 FPS without audio relay.Presentationmirrors the desktop at 1440p with audio relay enabled.
TargetBridge remembers the last selected profile for each discovered receiver, so choosing that receiver again restores the matching setup before the next connection. Profiles never change an active stream; stop the session before applying another one.
In Session Settings -> Diagnostics, select Check configuration to review the setup before starting a stream. The check is read-only and does not change macOS settings or request a permission by itself.
It reports:
- Screen Recording permission on the sender
- the selected local interface and whether it matches Thunderbolt Bridge
- whether a receiver address has been selected
- receiver profile and HEVC hardware-decoding support after the first connection
- the most recent Cable Test result
- the exact Accessibility and Input Monitoring permissions required by the active Input Dockstation role on both Macs
Some receiver checks are intentionally shown as pending until TargetBridge has connected once: the sender cannot inspect a remote Mac's hardware or privacy permissions before the receiver reports them over the session connection.
One sender can connect to multiple receivers at the same time, using multiple cables or links. Each session keeps its own transport, stream profile, display mode, and addon state.
This is useful for:
- one MacBook driving multiple old iMac panels
- separate receiver machines for side displays
- mixed mirror and extended workflows during testing
When multiple extended sessions are active, treat the sender Mac as the central coordinator for display layout.
Network Link reuses the same display pipeline over a local IP connection instead of only Thunderbolt Bridge.
It is intentionally marked experimental because:
- Thunderbolt is still the recommended low-latency path
- Wi-Fi and general LAN links have more jitter and more variable throughput
- hardware and home-network quality matter much more than with direct Thunderbolt
Use this when:
- the Macs are on the same LAN and you want to test the pipeline without a direct cable
- you want to reuse the same receiver discovery and session model over Ethernet or Wi-Fi
Related reading:
Audio Relay streams system audio from the sender to the receiver alongside the video stream.
The current implementation:
- captures system audio on the sender with ScreenCaptureKit
- converts it to low-overhead PCM for the receiver
- uses a receiver ring buffer and bounded backlog to stay responsive under jitter
- is designed for low-latency playback rather than archival-perfect sync
Related reading:
Input Dockstation adds keyboard and mouse relay between the connected Macs.
The key concepts are:
OffThis Mac is MasterReceiver is Master
Only one active master path should control input at a time.
When input relay is active, TargetBridge can also:
- switch control between slave sessions
- keep or relay control focus depending on the chosen role
- sync text clipboard contents in the direction of the active master
- expose role-specific hotkeys so the active master can switch sender Spaces or change slave target without leaving the session model
When Receiver is Master is active, the session settings can also store
custom shortcut bindings. A trigger pressed on the receiver runs an action on
the sender, which makes it possible to use a non-reserved trigger such as
Ctrl+Option+Left for a protected sender shortcut such as Ctrl+Left.
macOS asks once for permission to let TargetBridge control System Events on
the sender when a configured shortcut is first used.
This is useful for KVM-like workflows where one keyboard and mouse should control another connected Mac without leaving the TargetBridge session model.
Related reading:
The Sender menu can adjust a connected receiver's panel brightness and volume directly from the session controls. When the receiver hardware supports them, the same menu also offers Night Shift and True Tone toggles.
This makes it easier to treat the receiver as part of the same workspace without manually opening receiver-side display settings each time. Unsupported controls are simply not shown.
The Sender sends the selected setting over the session protocol and the Receiver applies it locally.
Sender and Receiver now use shared JSON language files stored in the repository.
The interface is available in English, Italian, German, French, and Chinese.
This makes it much easier to:
- update existing strings
- add a new language
- keep Sender and Receiver terminology aligned
Related reading:
TargetBridge already depends on Thunderbolt Bridge as a network path. That same link can also be used for standard peer-to-peer macOS services.
Examples:
- SSH / SFTP
- File Sharing
- Internet Sharing
- Time Machine to storage attached to the other Mac
- printer or storage sharing over the same cable
These are standard macOS networking features that can live alongside TargetBridge.
Related reading: