Home Assistant Yellow is the more advanced sibling of the Home Assistant Green, designed for people who want PoE power, expandable storage, and an integrated smart-home radio in a single, well-built piece of hardware. In 2026, the Yellow story has a wrinkle worth knowing about before you spend the money: the pre-assembled Standard model has been discontinued, and only the kit versions remain available.
This review covers what Yellow is, what makes it worth choosing over Green or a Raspberry Pi DIY build, and the practical reality of buying one in 2026.
What Home Assistant Yellow is
Home Assistant Yellow is a carrier board for a Raspberry Pi Compute Module 4 (CM4). The CM4 is a small, board-mountable variant of the Raspberry Pi 4 designed for integration into custom hardware. Yellow ships as a complete enclosed product, but the brains (the CM4 itself) is something you either get pre-installed (in the discontinued Standard version) or supply yourself (in the kit versions).
The Yellow carrier adds capabilities to the basic Pi platform that matter for a home automation hub:
- Power over Ethernet (PoE+), so you can power the device through your network switch rather than a wall adapter.
- M.2 NVMe storage, with an M-key socket supporting 2230, 2242, 2260, and 2280 modules over PCIe x1.
- Integrated Zigbee 3.0, OpenThread, and Matter radio, eliminating the need for a separate USB Zigbee coordinator.
- Gigabit ethernet with a real, well-shielded port.
- Real-time clock with battery backup, so your logs keep accurate time across power outages.
- Custom enclosure with a passive heatsink, sized at 123 mm x 123 mm x 36 mm.
The integrated radio is the feature that separates Yellow from a DIY Pi build most decisively. Pairing Zigbee devices, controlling Thread or Matter devices, and bridging to your existing smart-home ecosystem all happen on-board without a USB dongle dangling off the side.
The 2026 reality: the Standard model is discontinued
From Yellow's launch through 2024, you could buy a Standard model that arrived fully assembled with a pre-installed CM4 and Home Assistant OS. That option no longer exists. Nabu Casa announced the discontinuation of the Standard model, and what remains for sale are kit versions that require you to:
- Buy the Yellow carrier-board kit (carrier board, enclosure, heatsink, ethernet cable, but no CM4).
- Source a CM4 separately, either directly from Raspberry Pi distributors or from Nabu Casa as an add-on.
- Assemble the CM4 into the carrier (straightforward, but it is a real step).
- Flash Home Assistant OS to the CM4's eMMC or to an NVMe SSD installed in the M.2 slot.
None of this is hard. It is more involved than the truly plug-and-play Green, and the CM4 supply situation has been intermittently rocky over the past few years. Before committing, check current CM4 availability from Pi distributors like PiShop, Adafruit, and SeeedStudio.
For anyone considering Yellow today, the question is whether the PoE + integrated radio + NVMe combination is worth the added assembly versus Green or a Pi 5 build.
Who Yellow is for
Yellow makes sense if all three of these are true for you:
- You have PoE on your network. If your switch is not PoE+ capable, the headline feature of Yellow does nothing for you. Standard DC power works, but at that point a Pi 5 in a quality case offers similar capability for less money.
- You want one box, not three. Yellow consolidates server, Zigbee coordinator, and storage in a single enclosure. A DIY Pi build with a USB Zigbee stick and a separate SSD enclosure does the same thing for less money, but with more cables.
- You appreciate good industrial design. The Yellow case is heavy, well-made, and quiet. If you care about how your home automation hub looks on a shelf, this is the option that does not look like a hobby project.
If you do not have PoE, do not need integrated Zigbee/Thread/Matter radio, and do not value the integrated form factor enough to do the assembly, the Home Assistant Green is the better starter and a Raspberry Pi 5 with an SSD and a USB Zigbee coordinator is the better DIY option.
Setup notes
The assembly is approachable but worth previewing. The kit comes with the carrier board, enclosure, custom heatsink, and ethernet cable. You provide the CM4 and (optionally) an NVMe SSD.
The CM4 mounts to the carrier via two narrow board-to-board connectors. The connectors push together and are then held by two small screws. The custom heatsink applies firm contact pressure across the CM4's SoC and RAM. This is the only mechanically tricky step; once the CM4 is seated and the heatsink is screwed down, the rest is closing the enclosure.
For storage, the easiest path is a CM4 variant with eMMC and skipping the M.2 SSD entirely. This works fine for most installations. If you want NVMe (faster, more durable, larger capacity), install a 2230 or 2242 M.2 SSD before closing the case. Common choices include the Crucial P3 Plus 500 GB or the Western Digital SN740 (2230 form factor).
To install HAOS, follow the official Home Assistant flashing instructions for Yellow. The process uses Raspberry Pi Imager and takes about 10 minutes once you have the right files.
Real-world performance
For typical residential workloads (50 to 200 entities, a dozen automations, mobile app dashboards), Yellow with a CM4 4GB performs comparably to the Home Assistant Green: instant dashboard loads, automation latency under 500 ms, idle CPU around 5 to 10 percent. Both devices have headroom for the workloads they target.
Where Yellow's NVMe option pays off is workloads that hammer storage: long-history retention, frequent backup snapshots, or running heavy add-ons like AppDaemon or Frigate (which is a poor fit for either Yellow or Green, regardless of storage). The integrated Zigbee/Thread/Matter radio also delivers slightly better range and reliability than common USB coordinators, in practice not by a wide margin but noticeably for devices at the edge of your network.
Verdict: when to pick Yellow
Pick Yellow if you have PoE, want a single well-built box, and are comfortable assembling the CM4. The PoE story alone is worth the price for households that have invested in PoE infrastructure.
Pick the Green instead if you want the absolute simplest path to working Home Assistant.
Pick a Raspberry Pi 5 with USB Zigbee coordinator + SSD if you are budget-conscious or like having more flexibility for future tinkering.
For a deeper side-by-side comparison of Green and Yellow, see our Home Assistant Green vs Yellow breakdown. For the broader landscape of server hardware options, the Home Assistant server hardware guide covers Pi, mini PC, and DIY paths.
Frequently asked questions
Is Home Assistant Yellow still available in 2026?
The pre-assembled Standard model (which shipped with a Compute Module 4 included and Home Assistant OS pre-installed) has been discontinued. The kit versions, which require you to supply your own CM4, remain available from Nabu Casa as of 2026.
What is the difference between Home Assistant Green and Yellow?
Green is plug-and-play with fixed hardware (Rockchip RK3566, 4 GB RAM, 32 GB eMMC, $199). Yellow is a customizable platform that requires a Raspberry Pi Compute Module 4 (which you supply), adds PoE+ power, NVMe storage expansion, and an integrated Zigbee/Thread/Matter radio. Yellow is for advanced users; Green is for everyone else.
Do I need PoE for Home Assistant Yellow?
No. Yellow accepts both PoE+ and standard DC barrel power. The PoE feature is one of the main reasons to choose Yellow over alternatives, but it requires a PoE+ capable switch on your network to use.
What Compute Module 4 should I use with Yellow?
Yellow supports all 32 official CM4 variants (lite or with eMMC, with 1/2/4/8 GB RAM, with or without wireless). The recommended baseline is the CM4 with 4 GB RAM and 32 GB eMMC. Lite variants (no eMMC) require pairing with an NVMe SSD via the M.2 slot.
Is the CM4 still hard to find in 2026?
Supply has improved compared to the 2021 to 2023 shortage but is not always immediately stocked. Before buying a Yellow kit, verify CM4 availability at major Pi distributors. The eMMC variants tend to sell out faster than the lite variants.
Curated with AI assistance via Charmed.