Two speakers from different brands can play the same song at the same time only if both of them implement the same grouping protocol, and “works with Alexa” or “works with Google Assistant” on the box doesn’t tell you which protocol handles synchronized multi-room playback — voice control and audio sync are separate features that happen to share a brand logo.
In practice this narrows to two protocols that actually deliver synced grouping today: AirPlay 2 and Chromecast built-in (Google Cast). A third option, Matter Casting, gets mentioned as a coming fix, but as of this guide it doesn’t do synchronized multi-room grouping at all — it casts a single stream to a single target, similar to how AirPlay worked before AirPlay 2. Checking which of the two real protocols both your speakers support, before buying the second brand, is the difference between a system that plays in sync and one that just plays.
The protocols that actually sync across brands
AirPlay 2, launched by Apple in 2017, lets multiple AirPlay 2-certified speakers join a group and stay time-synchronized regardless of manufacturer, as long as each one implements the protocol. Apple’s own certified-partner list is broad for hi-fi and soundbar brands — Bluesound, Bose, Denon, Marantz, Naim, Sonos, and Yamaha all build it in — but notably does not include Google’s own Nest speaker line, which has never supported AirPlay 2.
Chromecast built-in (rebranded Google Cast in 2024) is Google’s equivalent: any two Cast-enabled devices on the same Wi-Fi network and Google Account can be added to a speaker group in the Google Home app and play in sync. Google’s own support documentation lists its own Nest speakers and displays alongside third-party Cast-licensed hardware from brands like Vizio, Sony, LG, JBL, and Bang & Olufsen. The catch is licensing: Google controls who gets Cast certification, and one major speaker brand has never had it.
Why Sonos and Google Nest speakers specifically cannot group together
Sonos is the clearest case of a “works with” claim not meaning what it implies for cross-brand sync. Sonos speakers support Google Assistant for voice control on select models, which makes it reasonable to assume they’d also work with Google’s Chromecast grouping — they don’t. Sonos has never implemented the Chromecast/Google Cast protocol, and Sonos’s own community support staff confirm directly that “Sonos does not support the Chromecast protocol, and never has,” which is why Sonos speakers never appear in a phone’s Cast device list.
Sonos does support AirPlay 2, added in 2018, which is why an iPhone can add a Sonos speaker to an AirPlay 2 group alongside a HomePod. But Google’s own Nest speakers and displays don’t support AirPlay 2 at all — Apple’s certified-partner list, cited above, doesn’t include them. The practical result: a Sonos speaker and a Google Nest speaker share no common grouping protocol in either direction. Voice control on both, sync on neither.
Part of why this gap exists is a multi-year patent dispute rather than a pure technical limitation. In January 2022, the U.S. International Trade Commission ruled that Google’s speaker-grouping implementation infringed five Sonos patents, and Google removed related features — including single-slider group volume control — from its own Nest speakers in response. A federal judge invalidated those patents in October 2023 and Google restored the removed features to its own product line, but the underlying commercial relationship between the two companies, including any Cast licensing for Sonos hardware, was never part of that resolution.
Google Cast: never supported
Google Cast: yes
Check protocol support before you buy a second brand
The question that actually predicts whether two speakers will sync isn’t “do they both work with my voice assistant” — it’s “do they both support the same grouping protocol.” Use this against the two brands you’re considering combining.
Why Matter Casting is not the fix yet
Matter Casting sounds, from the name alone, like the cross-brand answer this whole question is about — a single open standard that any certified device implements, the way Matter itself unified smart locks and thermostats across ecosystems. It isn’t there yet for multi-room audio specifically. Matter Casting, as specified through Matter 1.3, is built for casting a single media stream from a phone or tablet to a single target device — closer to original AirPlay than to AirPlay 2’s synchronized grouping. As of this guide, Amazon is the only major platform with a shipped Matter Casting implementation (on Fire TV), and there is no Matter specification yet for synchronized multi-speaker groups; Sonos’s own community forum discussion of Matter adoption confirms there’s currently no Matter standard for multiroom audio at all.
Treat “Matter compatible” on a future speaker as a signal about lock- and sensor-style device control, not as a promise that it will group and sync with a speaker from a different brand. That capability, if it arrives, is a separate part of the Matter specification that hasn’t shipped for audio yet.
Compatibility matrix — protocol support by brand
Verified against each platform’s current developer and support documentation as of this guide — always confirm the specific model, since “varies by model” rows depend on individual product certification.
Before You Buy
Before adding a second brand to an existing speaker setup, identify which single protocol — AirPlay 2 or Chromecast/Google Cast — both your current speakers and the new ones actually implement, and confirm it against the specific model rather than the brand generally, since support can vary within a single manufacturer’s lineup. A “works with Alexa” or “works with Google Assistant” badge tells you about voice control, not about whether two speakers can join the same synchronized group. If your existing system is Sonos and you’re considering a Google Nest speaker, or vice versa, understand upfront that the two currently share no grouping protocol in either direction — that’s not a setup mistake to troubleshoot, it’s the documented state of both ecosystems today.
Frequently Asked Questions
Can Sonos and HomePod play together in sync?
Yes, via AirPlay 2 — Sonos added AirPlay 2 support in 2018, and both a HomePod and a Sonos speaker can join the same AirPlay 2 group. Some users report minor timing drift over long sessions in mixed Sonos/HomePod groups, which is a documented AirPlay 2 characteristic worth testing in your own space before buying more speakers, though basic sync works.
Why doesn’t my Sonos speaker show up when I try to Chromecast from my phone?
Because Sonos has never implemented the Chromecast/Google Cast protocol — this isn’t a setup or network issue. Sonos speakers only appear as AirPlay or Bluetooth targets, never as Cast targets, regardless of account linking or app settings.
Will Matter fix cross-brand speaker grouping soon?
Not in its current form. Matter Casting exists but is built for single-target media casting, not synchronized multi-room speaker groups, and as of this guide there is no Matter specification for multiroom audio sync. Treat any “Matter compatible” speaker label as being about device control, not grouped playback.
Can I mix Alexa and Google speakers in one multi-room system?
Voice-assistant brand and grouping protocol are separate questions. An Echo device and a Google Nest speaker don’t share a native grouping protocol with each other by default — check whether both support Chromecast/Google Cast specifically (some newer Echo hardware does not), rather than assuming voice-assistant compatibility implies sync compatibility.
