Matter + Thread · read 2026-09-19

You cannot fully answer this, and it is not your fault.

Whether two Thread border routers can join one network comes down to three things: the Thread version each one runs, whether its vendor implemented credential sharing, and whether the app gives you a button for it.

We read what all four major ecosystems publish about their border routers. 1 of 4 publishes the Thread version. Without it, the first of those three questions has no public answer — which is why people end up running dns-sd by hand to read it off the wire.

33 devices across 4 ecosystems. 2 of the 4 pages carry any date at all, so for the others there is no way to tell how current the list is — including for us.

• Amazon's entire published range is Thread 1.1 or 1.3, not 1.4. Thread 1.4 is the release that introduced standard credential sharing. Amazon instead documents its own Credential Locker API, available to Alexa add-on developers with the customer's consent. So an Echo or eero joining an Apple- or Google-created network is not something either side's documentation describes.
• Only one consumer-facing sharing step is documented anywhere. It is Home Assistant's, it is Android-only, and it is three levels into a troubleshooting menu: Settings → Companion app → Troubleshooting → Sync Thread credentials. If you have been looking for a button, that is the closest thing to one.
• Apple lists Thread-enabled devices, not border routers. The distinction matters: an iPhone 15 Pro appears on Apple's list and can pair accessories, but the page does not say it acts as a border router. Buying a phone will not give you one.

What none of this can tell you is whether two specific units will actually merge in your house. That depends on firmware shipped after these pages were written. The honest position is that the published record does not settle it.

Thread-enabled Amazon Echo and eero devices have built-in Thread Border Routers and support Thread version 1.1 or 1.3 defined by the Thread Group.

• Echo (4th Gen) Thread 1.1
• Echo Dot Max (2025 release) Thread 1.3
• Echo Hub Thread 1.3
• Echo Plus (2nd Gen) Thread 1.3
• Echo Show 21 Thread 1.3
• Echo Show 15 (2nd Gen) Thread 1.3
• Echo Show 11 (2025 release) Thread 1.3
• Echo Show 10 (3rd Gen) Thread 1.3
• Echo Show 8 (3rd Gen, 2025 release) Thread 1.3
• Echo Studio (1st Gen and newer, 2025 release) Thread 1.3
• eero 6 and eero 6+ Thread 1.3
• eero 7 Thread 1.3
• eero Beacon Thread 1.3
• eero Max 7 Thread 1.3
• eero Outdoor 7 Thread 1.3
• eero PoE 6 Thread 1.3
• eero PoE gateway Thread 1.3
• eero Pro Thread 1.3
• eero Pro 6E and eero Pro 6 Thread 1.3
• eero Pro 7 Thread 1.3

On sharing credentials. “You can use the Credential Locker REST API in your smart home add-on to get customer Thread network credentials or create a new customer Thread network for Matter device setup.”

This is Amazon's own API, available to developers of Alexa smart-home add-ons with the customer's consent. It is not the Thread 1.4 credential-sharing mechanism.

Source: Alexa developer documentation · the page is dated 2026-05-01 · we read it on 2026-09-19

• Apple TV 4K (3rd generation) Wi-Fi + Ethernet version not published
• Apple TV 4K (2nd generation) version not published
• HomePod (2nd generation) version not published
• HomePod mini version not published
• iPhone 15 Pro, iPhone 15 Pro Max, or later running iOS 18 version not published

This page does not describe sharing Thread credentials with another ecosystem.

Worth knowing. Apple lists these as Thread-enabled devices rather than specifically as border routers. The iPhone entry can pair accessories; the page does not say it acts as a border router.

Source: Apple Support 102078 · the page is dated 2026-01-13 · we read it on 2026-09-19

• Google Home Speaker (2026) version not published
• Nest Hub (2nd gen) version not published
• Nest Hub Max version not published
• Nest Wifi Pro (Wi-Fi 6E) version not published
• Google TV Streamer (4K) version not published

This page does not discuss sharing Thread network credentials with another ecosystem.

Worth knowing. This page carries no publication or last-updated date at all.

Source: Google Nest Help — Prepare your smart home for Matter · the page carries no date · we read it on 2026-09-19

• Home Assistant Yellow (using its Thread radio) version not published
• Connect ZBT-1 (using its Thread radio) version not published
• Connect ZBT-2 with the OpenThread Border Router add-on version not published

On sharing credentials. “In the Companion app, go to Settings > Companion app > Troubleshooting, then select Sync Thread credentials.”

This is the only consumer-facing credential-sharing step any of these four ecosystems documents, and it is Android-only. It is buried three levels into a troubleshooting menu.

Worth knowing. The page states the Connect ZBT-1, Connect ZBT-2 and Yellow run Zigbee rather than Thread, and separately that their Thread radio can be used. Home Assistant's own 2026.9 release notes name the Connect ZBT-2 with the OpenThread Border Router add-on as a border router example. Read both before ordering hardware.

Source: Home Assistant Thread integration documentation · the page carries no date · we read it on 2026-09-19

Trying to work out why a device will not commission at all? The log reader will tell you which layer your error is in before you start changing border routers.