Setup and every function.
The steps from download to a paired device, then each function in one or two lines.
Setup
Download and open
Open the disk image, drag AirExtend to Applications and open it. It lives in the menu bar and has no Dock icon.
Install the audio driver, once
Click Install under Audio driver in the panel and enter the administrator password. Two devices appear on the Mac: AirExtend (output) and AirExtend Mic (input).
Allow three permissions
Microphone, Screen Recording and Local Network. The panel shows a Permissions needed row until all three are given. Screen Recording applies after a restart of AirExtend.
Pair a device
Scan the QR code with the phone’s camera, or open the address under it and type the six-digit code. The code changes every ten minutes and can be renewed by hand. Pair once per device.
Choose a mode
Communicator or Broadcast, in the panel. Every device follows the Mac.
Pick what to share
In Settings, Sources: the whole Mac or chosen apps. Chosen apps can be muted on the Mac while they stream.
Functions
- Communicator
- Each device is its own live stream: lossless, about 20 ms. Any number of devices, not in step with each other. The phone’s microphone returns as AirExtend Mic.
- Broadcast
- One shared delay from 0.3 to 60 seconds, 5 s by default. Every phone, tablet and TV plays the same moment.
- Stream type
- Lossless: bit-perfect, about 1.6 Mb/s per listener, best for up to about 20. Compact (AAC): 192 kb/s per listener, for hundreds.
- Auto-sync
- The Mac’s microphone listens to a test sound from each device in turn and measures how late it plays.
- Sync test and Tighten
- Sync test repeats the measurement. Tighten refines the alignment.
- Per-device delay
- On the device: −10, −1, +1, +10 and Reset, for speakers, Bluetooth and TVs.
- Music mode
- Lossless with a bigger buffer, about a quarter of a second. Keeps playing in the background on iPhone.
- Microphone
- The phone’s microphone goes to the Mac as AirExtend Mic. Mic gain, Sound gain, a test tone and a test mic are on the phone.
- Equalizer
- Ten bands from 31 Hz to 16 kHz. Presets: Flat, Bass, Vocal, Treble, Loudness and Custom.
- Mac screen
- Whole screen or one app window to the phone, with the sound in step. Shows delay and frame rate. Full screen and Picture in Picture on iPhone.
- Video quality
- 720p, 1080p, 1440p or 4K, up to 60 fps. 1080p is about 12 Mb/s. 1440p and 4K want Wi-Fi 6 or 5 GHz near the router.
- TV-shaped screen
- A virtual 16:9 display for TVs, so the TV gets a full frame instead of a crop of the laptop screen. In the next Mac update.
- HEVC video (test)
- An optional, lighter video format for TVs that decode it. In the next Mac update, off by default.
- Open access
- Removes pairing codes: anyone on the network who opens the address can listen, see the screen and use the phone microphone. Off by default.
- Address
- The Mac answers at airextend.local, and the name can be changed. Android, Windows and TVs use the IP address, which the QR code contains.
- Devices list
- Each connected device and its round-trip time, in Settings.
- Transport
- Standard: lossless PCM, the lowest delay. For a weak Wi-Fi network: Low data, AAC at 128 kb/s, or WebRTC with Opus, which survives lost packets and adapts to the link. WebRTC keeps playing in the background in iPhone Safari and in Picture in Picture, with a little more delay and the equalizer off. Chosen on the listener’s page.
- Reconnects by itself
- If the network changes or a VPN starts, devices rejoin within a few seconds.
- Local HTTPS
- The page uses a local certificate for HTTPS and falls back to HTTP without one.
On the other side
- Browser
- Any current browser on a phone, tablet, TV or computer: sound, screen, microphone, equalizer.
- iPhone and iPad
- iOS and iPadOS 17 or later. Background playback, the microphone in the background, Picture in Picture and the lowest delay. In App Store review.
- LG webOS TV
- A TV layout with the picture first as a tile that opens full screen, a Fill screen option and TV-sized controls. In testing, needs the next Mac update.
- Android TV
- The same TV layout for Android TV and Google TV. In testing, needs the next Mac update.
Functions marked “next Mac update” are built and not yet in the downloadable version.