Every speaker in your house, at the same volume.
Turn one Google Home or Nest speaker up and the rest follow. Google Home Volume Sync runs quietly on a Windows PC, watches every Cast device on your network and keeps the groups you choose perfectly matched — with a per-room gain so the kitchen never drowns out the bedroom.
Free. No account, no cloud — it talks to your speakers directly on your LAN. Starts with Windows and lives in the tray.
What it does
One always-on PC, every speaker in step. Nothing leaves your network.
Google Home, Nest Mini, Nest Audio, Nest Hub, Chromecasts and cast groups appear automatically — new devices just show up.
Group any speakers; change one volume anywhere — in this app, on your phone, or on the speaker itself — and the rest follow instantly.
Set a per-device 0–200% gain so quiet corners get boosted and loud rooms stay tame, while the group still moves as one.
Right-click the tray icon and set any group to 5%…100% in two clicks, plus play / pause / next / previous.
Quiet the house at bedtime: weekly day-and-time rules that set volumes for groups or single devices.
Also controls Roku TVs, Yamaha MusicCast receivers, LG webOS TVs and Optoma projectors, in the same sync groups.
Roku is tested on real hardware. The Yamaha, LG and Optoma backends are written to spec but untested — reports welcome.
See it in action
Straight from the app — a real house with twenty Cast devices.
Sync groups that actually stay in sync
Tick the speakers you want to move together. When any member changes — from the app, the Google Home app, or a tap on the speaker — the others are set to match within a moment. Groups are yours, independent of Google’s cast groups, and each one has its own slider and media controls.
Whole-house volume from the tray
You don’t need to open the window. Right-click the tray icon, pick a group, pick a level. 5% steps, plus play, pause, next and previous for whatever is casting.
Schedules for bedtime and mornings
Weekly rules with a time and day checkboxes: drop “Everything” to 50% at 10 pm on school nights, bring the kitchen back up in the morning. Each rule can target several groups or devices at different levels, and toggles on and off with one checkbox.
Set it and forget it
Start with Windows, minimised to the tray. Optional automatic updates from GitHub releases. Export your devices, names, groups and schedules to a JSON file and import them on another PC.
Hardware that pairs well with it
What runs it, and what it controls. Amazon affiliate links — they cost you nothing extra and help keep the app free.
Beelink Mini S12 Pro — Intel N100, 16 GB, 500 GB, Windows 11
★★★★★★★★★★ 4.5 (269 ratings)
The classic always-on box: about 6 W at idle, fanless-quiet, and it disappears behind a monitor. Runs the sync service around the clock so your speakers stay matched even when your main PC is off.
View on Amazon
Google Nest Mini (2nd Gen) — Charcoal
★★★★★★★★★★ 4.3 (2,153 ratings)
The cheapest way to put synced audio in every room. Google has stopped making it, so stock on Amazon comes and goes — check the buying options and the seller.
View on Amazon
Google Nest Audio — Chalk
★★★★★★★★★★ 4.5 (214 ratings)
Bigger sound for living spaces. Two pair into a stereo set that this app treats as one device, so a whole room moves with one slider.
View on Amazon
Google Nest Hub (2nd Gen) — 7″ smart display
★★★★★★★★★★ 4.2 (1.1K ratings)
A screen for the kitchen or bedside — shows what’s playing and joins sync groups like any speaker. Availability on Amazon varies, so it’s worth watching the listing.
View on Amazon
Google Nest Hub Max — 10″ display with big speakers
The big-screen, big-speaker option for the main room. Only imported units are listed on Amazon right now, so check the region and plug type before ordering.
Browse on Amazon
Chromecast with Google TV (4K)
Brings your TV into the same volume groups and schedules. Current Amazon listings are mostly resellers rather than the Google Store, so compare prices before you buy.
Browse on Amazon
As an Amazon Associate this site earns from qualifying purchases. Ratings shown as read in September 2026. This is an independent site, not associated with Google or any seller; cards marked “Browse” open an Amazon search because there is no current first-party listing to point at.
Did it make your house sound better?
Google Home Volume Sync is free and open source, built and maintained by one person. If it saved you from shouting “Hey Google, volume down” in three rooms, a coffee goes a long way toward keeping it that way. A Ferrari would go further, but I’ll settle for the coffee.