Google Nest Protect (2nd gen)

Compiled by SmartHomeWorkflow Research · Google Nest · Security Systems & Alarms

Discontinued is not the same as dead, and the two are recorded separately on purpose. No end-of-service date for the app or notifications has been published as of 2026-07-19. The real hard stop is the device's own 10-year expiry, not a server shutdown. Google stopped making it, and every unit carries a hard 10-year expiry counted from its manufacture date rather than the day you bought it — so a clearance or secondhand unit may have very little life left, and it ends by chirping and announcing its own expiry in a way you cannot dismiss. Separately: for a safety device, smoke and CO events reach Google's own apps and nowhere else.

Compatibility

Ecosystem	Support	The catch
Google Home	PartialPartial support — see the catch	Now managed in the Google Home app, but four features stay Nest-app-only (Video Capture, Emergency Shutoff, emergency contacts, and "What to do") — and the legacy Nest app is still mandatory for initial setup and factory reset, on a product line Google is migrating away from
Amazon Alexa	Doesn't workVerified: does not work with this ecosystem	Google's own Alexa support page lists the entire supported set as Nest cameras, doorbells and thermostats — Protect is absent. Every legacy third-party path ran on Works with Nest, which stopped functioning 2023-09-29 and was never replaced for alarms.
Apple Home	Doesn't workVerified: does not work with this ecosystem	Never HomeKit-certified, and with no Thread or Matter stack there is no Matter route either. The Starling Home Hub bridge that used to solve this is itself no longer sold, so the last practical workaround is gone. Note the evidence is absence across Google's and Apple's own pages rather than an explicit statement from either.
SmartThings	Doesn't workVerified: does not work with this ecosystem	SmartThings' own Nest partner page lists supported categories as Camera, Doorbell and Thermostat. Protect is absent from a vendor-published list.
Home Assistant	Doesn't workVerified: does not work with this ecosystem	Home Assistant states it outright: smoke and CO alarms are "not currently supported by the SDM API." Confirmed upstream — Google's own Smart Device Access supported-device list covers cameras, doorbells, displays and thermostats only. There is no supported API path for any third party to receive a Nest Protect alarm.

Protocols: WIFI · BLUETOOTH

Subscription reality

✓ Works without a subscription: Yes.

No paid plan gates anything on Nest Protect itself. Nest Aware's smoke/CO 'sound detection' is a camera and speaker feature — it listens for an alarm noise and does not involve the Protect.

Maintenance reality

Batteries: 6× Energizer Ultimate Lithium L91 AA (battery model); 3× L91 AA backup (wired model)
Cloud dependence: No — core function survives without the vendor's cloud
Hard 10-year lifespan from the DATE OF MANUFACTURE printed on the unit, forced by the CO sensor and required for certification. At expiry the device chirps continuously, shows a yellow ring at night, and speaks a replacement warning. Local alarming and the peer-to-peer interconnect work without internet; Wi-Fi is needed only for phone notifications, remote status and firmware.

Who it's for

Existing owners deciding whether to keep a working unit — the answer is that it still works and still gets firmware, until its expiry date. Anyone buying new should look at the First Alert SC5, which Google itself names as the replacement and which interconnects with existing Protects.

Sources & method

support.google.com/googlehome/answer/15709068 ("no longer available for sale, but is still supported"); support.google.com/googlenest/answer/9249942 (firmware 3.6, March 2025, post-discontinuation); support.google.com/googlehome/answer/15731767 and .../9249296 (10-year replacement from manufacture date; expiry chirp and spoken warning) — vendor-page research, verified 2026-07-19 · The 2025-03-28 announcement date is reported by tech press only. The Google Nest Community blog was reorganized and the original post could not be located on a Google-owned domain; archive access was unavailable. The FACT of discontinuation is primary-sourced; the date is not, so soldUntil is 'ended' rather than a year. — sourcing gap, recorded honestly, verified 2026-07-19 · support.google.com/googlenest/answer/9229922 lists Wi-Fi 802.11 b/g/n 2.4 GHz only, 802.15.4 at 2.4 GHz, and Bluetooth LE. The 802.15.4 radio runs Google's proprietary Weave interconnect for Protect-to-Protect messaging — it is neither a Thread endpoint nor a border router, so 'thread' is deliberately not listed in protocols. — vendor-page research, verified 2026-07-19 · Counterparty sources per 09 §3: support.google.com/googlehome/answer/9325080 (Alexa-supported set omits Protect); partners.smartthings.com/partners/nest (Camera, Doorbell, Thermostat only); home-assistant.io/integrations/nest plus developers.google.com/nest/device-access/supported-devices (smoke and CO alarms not supported by the SDM API). Root cause across all three: Works with Nest terminated 2023-09-29 (support.google.com/googlehome/answer/9293712). — counterparty-source research, verified 2026-07-19 · support.google.com/googlehome/answer/15731767 and .../16324143 — Google names the First Alert Smart Smoke & CO Alarm as the compatible replacement and documents cross-interconnect between the two. Supersession recorded in supersededBy. — vendor-page research, verified 2026-07-19 · Launch price was $99 at 2nd-gen announcement (blog.google), but the product is no longer sold and the final Google Store price could not be retrieved (client-side rendering; archive unavailable). A stale launch price on a discontinued product would mislead, so priceUSD stays null. — sourcing gap, recorded honestly, verified 2026-07-19 · The 2014 CPSC recall-to-repair (~440,000 units, Nest Wave gesture) covered 1ST GEN units sold 2013-11-15 to 2014-04-03. This record is 2nd gen, which postdates it and is not affected. Recorded so the scope is stated rather than implied. CPSC page returned HTTP 403 on direct fetch; treated as secondary pending re-verification. — regulator-source research (fetch blocked, flagged), verified 2026-07-19. This is a research profile: compiled from manufacturer documentation, certification registries, and published testing — we state facts, not verdicts, and we have not physically tested this unit. How we work →

Compatibility and lifecycle information reflects the last-verified date above and can change without notice (firmware updates, cloud-service changes, discontinuations). It is provided as-is, for information — verify with the manufacturer before purchasing. Spot an error? Tell us and we'll fix it. Full terms: Terms of Service.

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