RoomCast FAQ: stream Mac audio to phones for silent discos, parties and events

RoomCast is a free, open-source Mac app that streams live audio from a Mac over the local Wi-Fi to listeners' phones. Listeners scan a QR code and hear the sound in their phone's web browser, with no sign-in. It runs on macOS 13 Ventura or later (Apple silicon and Intel).

RoomCast is a universal Mac app for Apple silicon and Intel Macs running macOS 13 Ventura or later, which covers roughly 2017 and newer Macs: iMac (2017 and later), iMac Pro, MacBook Pro (2017 and later), MacBook Air (2018 and later), MacBook (2017), Mac mini (2018 and later), Mac Pro (2019 and later), Mac Studio, and every Apple silicon Mac.

Yes. RoomCast is free to download and use, and its source code is open on GitHub. It is supported by donations through Ko-fi, Patreon and Buy Me a Coffee.

No. RoomCast listeners scan the QR poster with their phone camera and listen in the browser on iPhone or Android. No account needed.

Connect the phone to the same local Wi-Fi as the Mac (the Wi-Fi does not need internet). Scan the RoomCast QR poster with the phone camera; the stream opens in the browser on iPhone or Android. No account needed.

No. RoomCast only needs a local Wi-Fi network that the Mac and the phones share. The Wi-Fi does not need internet access, so RoomCast works in halls, basements and remote venues. If phones cannot connect, see troubleshooting.

RoomCast can broadcast your Mac's built-in microphone, a USB or Bluetooth headset, a mixing desk or audio interface for larger events, or the sound of a music app or DJ software. To capture music-app or DJ-software audio, RoomCast currently needs the free BlackHole 2ch driver — see How do I broadcast music from Spotify, a music app, or DJ software with RoomCast? on this page.

Install the free BlackHole 2ch driver, route Spotify or another music app into it, then choose BlackHole 2ch (or Broadcast music from an app) in RoomCast and press Broadcast. RoomCast does not capture other apps’ audio by itself yet — BlackHole is required for that path. The full walkthrough is in Broadcast music from an app in the user manual.

If you use Spotify or another streaming service, check that subscription’s terms for public or event playback — we cannot advise on what your plan allows.

Tip: you can tweak the sound volumes of each device in Audio MIDI Setup. Try all of this before the party, so on the night it's stress-free — and you look like the Boss.

For a party / silent disco setup, see the silent disco from your Mac guide.

RoomCast just carries sound from your Mac. As with any speaker system, make sure you have the right to play the music at your event — your own recordings, licensed or royalty-free tracks, or a venue licence. If you use Spotify or another streaming service, check your subscription’s terms for public or event playback; we cannot advise on what your plan allows.

Yes. Churches, mosques, temples, synagogues, gurdwaras and meditation centres can use RoomCast to carry a service or talk to an overflow room, to a parents' room or cry room, or to anyone who is hard of hearing. Listeners use the phones they already have, so there are no receivers to buy or hand out. See also overflow & parents’ room setups, quiet or sensory room participation, and hearing-loop alternatives.

Yes. Play the DJ set or playlist on a Mac, broadcast with RoomCast over the venue’s local Wi-Fi, and have guests scan the QR poster to listen in their phone browser on their own earbuds or headphones — no internet required on that Wi-Fi. For music apps or DJ software you currently need BlackHole 2ch (see the music-broadcast question on this page). Full walkthrough: silent disco. For a late party that stays considerate of neighbours and local noise rules: party till dawn.

Feed a line or USB interface from the mixing desk into the Mac, choose that input in RoomCast, press Broadcast, and show the QR poster. Guests in overflow seating, a parents’ or cry room, foyer or lobby join in the browser on the same Wi-Fi — or plug a listening laptop into a small speaker if you want room speakers instead of earbuds. Guides: overflow & parents’ room audio, overflow with a Bluetooth speaker, and quiet or sensory room participation.

A hearing loop serves telecoil hearing aids without a phone; Auracast is a Bluetooth broadcast that needs compatible devices and transmitters. RoomCast is different: it streams room audio over local Wi-Fi so people listen in their phone's browser. It can help when you want overflow, parents’ room, or BYOD listening on phones and earbuds people already have. RoomCast is not a drop-in replacement for a specified assistive-listening installation — if a building rule or accessibility plan requires a loop, infrared, FM, or a listed system, follow that plan. RoomCast can sit alongside those systems for phone users. Practical how-to when a loop is out of budget: hard of hearing at an event without a hearing loop. More detail: hearing loop alternatives and Auracast vs hearing loop vs Wi-Fi.

Listen Everywhere / ListenWIFI and AudioFetch are commercial Wi-Fi audio systems: venues typically buy hardware and listeners use a free app (or borrowed receivers). RoomCast is a free, open-source Mac app: the host Mac streams over local Wi-Fi and listeners join in the browser. No account needed. RoomCast is not a drop-in replacement for a specified assistive-listening install. Comparison: Listen Everywhere & AudioFetch vs RoomCast.

Listeners hear RoomCast on the phone they already have. Earbuds or headphones are what people typically use so each person sets their own volume; the site’s silent-disco and worship guides describe listening on earbuds or headphones. You can also use a phone or laptop as a feed into a small speaker in an overflow room (see the overflow guide and Bluetooth speaker overflow). The same phone-plus-speaker idea works for a bingo table in a hall with a weak PA — see bingo and called numbers.

About 50 phones on a modern Wi-Fi router can listen at once. The real number depends on the router, other traffic on the network, distance and walls, and the quality setting. The Mac serves listeners directly. Ordinary home or venue Wi-Fi is usually enough for a typical room; for larger events use a strong access point and test beforehand.

The delay is usually around half a second, even on busy Wi-Fi. That suits talks, live translation, teaching and music; it's not meant for lip-sync to live video.

No. RoomCast has no sign-in and no cloud; audio goes from your Mac straight to phones on the same Wi-Fi and never leaves the room's network.

Download RoomCast for Mac, open it and drag RoomCast into Applications. On first launch, allow microphone access so RoomCast can hear your sound source. When you first press Broadcast, macOS may ask whether RoomCast may accept incoming network connections; click Allow, or phones will not be able to connect. Step-by-step detail is in Getting started in the user manual.

The RoomCast host app runs on Mac only today (universal app, macOS 13 Ventura or later). iPhone and Android are listener devices: they join in the browser, they do not run the host app. A Windows host version is planned once donations make it possible.

Yes. RoomCast has a broadcast volume control in decibels: 0 dB leaves the volume unchanged, and you can raise or lower it. Each listener also sets their own phone volume.

Check that phones are on the same Wi-Fi as the Mac, that you clicked Allow for incoming network connections when macOS asked, and that Broadcast is on. See the troubleshooting page and Getting started in the user manual.