Home Assistant Yellow: Full Review & Setup Guide (2026)

Disclosure: Some links in this article are affiliate links. We may earn a commission on qualifying purchases at no extra cost to you.

Home Assistant Yellow was, for a few years, the closest thing to a "reference hub" for anyone serious about local control — a carrier board with a soldered Zigbee/Thread radio, an NVMe slot, and a design built specifically to run Home Assistant OS without a single cloud dependency. Then, on October 15, 2025, Nabu Casa pulled the plug: the Yellow is officially discontinued, remaining stock is scattered across a handful of specialty retailers, and it never had a proper Amazon listing to begin with.

That leaves two very different readers looking for the same review. One already owns a Yellow and needs a real setup and troubleshooting guide — SSD migration, Zigbee firmware quirks, PoE that refuses to power on. The other is deciding whether to chase down new-old-stock in 2026 or spend that money on a Home Assistant Green, a Raspberry Pi 5 build, or a mini PC instead.

This guide covers both. It breaks down what the Yellow actually is (and isn't), what changed with Compute Module 5 support, the accessories that make or break the experience, and — because the hub itself isn't the honest recommendation for most new buyers anymore — where the money is better spent.

Specs at a Glance

Quick Verdict

The Yellow is still a genuinely well-engineered hub, and if you already own one, it's worth keeping and maintaining — the integrated radio and NVMe support hold up fine in 2026. But as a new purchase, it's a hard sell: it's out of production, doesn't include the compute module you need to actually run it, and the Home Assistant Green now covers the plug-and-play case while a Raspberry Pi 5 build covers the tinkerer case, both without hunting for discontinued stock.

Home Assistant Yellow — Overview & First Impressions

The Yellow was never meant to be a finished appliance out of the box — that distinction belonged to the pre-assembled Yellow Standard, which shipped with a Compute Module 4 already installed and Home Assistant OS pre-flashed. The version most people bought, the Yellow Kit, is a carrier board in a translucent enclosure: you supply your own CM4 (or, since HAOS 14, a CM5), and the board handles the rest — Zigbee radio, Ethernet, NVMe expansion, and a clean plastic case that doesn't look out of place on a shelf next to a router.

That "bring your own compute module" design was the Yellow's biggest strength and its biggest friction point at the same time. During the 2021–2023 chip shortage, plenty of buyers ended up with a Yellow Kit sitting in a drawer for months waiting on a CM4 to become available. In 2026, the shortage has eased, but a new problem has replaced it: both the Yellow Kit and the CM4 modules that power it are now largely out of stock at reputable resellers, and the Yellow line itself has reached end-of-life.

First impressions for anyone assembling one today are still positive on the hardware side — tool-free assembly, a passive heat sink that actually keeps a CM4 cool, and a soldered radio that removes one more USB dongle from the back of your router. The catch is entirely about availability and long-term platform direction, not build quality.

Specs & What's in the Box

The standard Yellow Kit box contains the carrier board, the polycarbonate enclosure halves, a passive heat sink, an Ethernet cable, and a universal power supply with regional plug heads. It does not include a Compute Module — that's a separate purchase, and in 2026 it's the harder half of the equation to source.

Three variants exist, and it's worth knowing which one you're looking at if buying used or from remaining stock:

• Yellow Kit — carrier board, enclosure, and barrel-jack power supply. No CM4/CM5 included.
• Yellow Kit PoE — same carrier board, but powered over Ethernet (802.3at, Class 3 by default, switchable to Class 4 via an onboard jumper) instead of a barrel jack. No power supply in the box at all — you need a PoE+ switch or injector.
• Yellow Standard — the original pre-assembled version with a CM4 (2GB RAM / 16GB eMMC) and HAOS already installed. Manufacturing on this variant ended in 2024, ahead of the full line's discontinuation in 2025.

The onboard radio deserves a specific callout because it's frequently misdescribed: it's a soldered Silicon Labs MGM210P "Mighty Gecko" chip, not a SkyConnect or Connect ZBT dongle bolted to the board. It handles Zigbee 3.0, OpenThread, and Matter-over-Thread — but not Zigbee and Thread simultaneously in a fully robust way, so you pick one role for the radio at a time.

The M.2 slot accepts NVMe drives in 2230 through 2280 form factors over a PCIe x1 link. It does not support the Google Coral USB/M.2 accelerator, so anyone planning heavier Frigate object-detection work should look elsewhere for acceleration.

Build Quality & Durability

The enclosure is a V-0 fire-rated polycarbonate shell that snaps together without tools, and the passive heat sink is sized correctly for the CM4 — idle power draw sits around 1.5W, climbing to roughly 2.5W with an NVMe drive installed and 5–9W under sustained load. That's low enough that thermal throttling isn't a real-world concern on the CM4.

The CM5 is a different story. It's supported as of HAOS 14, and it's meaningfully faster — community benchmarking puts the CPU at roughly 2-3x the CM4's performance and RAM bandwidth at 3-4x, essentially for free once the module is dropped in. But the CM5 also draws close to double the power under load, and it runs hotter in the same passive enclosure. If you're upgrading a Yellow to a CM5, plan on it running warmer than you're used to, and don't be surprised to see community fan mods on forums — they're addressing a real thermal gap, not a rare edge case.

One assembly detail worth flagging before you touch a screwdriver: do not reuse the CM4's mounting screws on a CM5. The screw specification changed between modules, and using the wrong ones risks damaging the board.

Long-term durability on the Yellow itself has been solid — the complaints in owner communities are almost entirely about compute module and storage compatibility, not the carrier board or enclosure failing on its own.

Performance — CM4 vs. CM5, Radio, and Storage

Performance on a Yellow is really a function of three separate things: the compute module you choose, the storage you pair with it, and how you're using the onboard radio.

Compute module. A CM4 at 4GB RAM/32GB eMMC handles a typical Home Assistant install — dozens of integrations, a handful of automations, a moderate Zigbee network — without breaking a sweat. The 8GB CM4 variant is genuinely overkill for most homes; it's aimed at power users running many add-ons, heavier local voice processing, or camera-adjacent workloads. A CM5 is the real performance upgrade if you're feeling the CM4 struggle, at the cost of extra heat and a few installation quirks (it can't boot the HAOS installer over USB 2.0, so you'll need rpiboot, and a 16GB CM5 shows only 8GB unless you're running HAOS 16 or later).

Storage. This is where most of the reported "performance problems" actually live, and it's rarely the compute module's fault. The CM4's PCIe x1 link is picky about which NVMe drives it tolerates — some budget, DRAM-less drives and even certain Samsung 980 units have been reported to cause random crashes and I/O errors. Owners who've had good, stable results consistently point to a short known-good list rather than "any NVMe drive will do."

Radio. The MGM210P performs well as a Zigbee 3.0 coordinator for typical home-sized networks, and its Matter-over-Thread capability is a real advantage for readers building a mixed Zigbee/Thread setup. The one recurring headache is firmware: the EmberZNet update path (6.10.3.0 to 7.4.4.1) has failed to flash for a number of users, sometimes leaving the radio non-functional until it's manually re-flashed with the universal-silabs-flasher tool. If you're updating radio firmware on a Yellow, back up your Zigbee network settings first and don't assume the update will complete cleanly on the first try.

Home Assistant Yellow vs. Home Assistant Green — Head-to-Head

This is the comparison every 2026 buyer actually needs, because Green is now Nabu Casa's default recommendation for anyone not deep into the DIY compute-module ecosystem.

The trade-off is straightforward. Yellow gives you an integrated radio and expandable NVMe storage, at the cost of having to source an increasingly hard-to-find compute module. Green is fully assembled and currently in production, but its storage is fixed at 32GB with no expansion path, and it has no onboard radio at all — you'll need to add a Connect ZBT-2 dongle for Zigbee/Thread/Matter, which is itself the direct successor to the old SkyConnect/Connect ZBT-1 (now discontinued).

It's also worth noting that Green's pricing has shifted: Nabu Casa raised its suggested retail price significantly effective April 24, 2026, citing higher component costs. That changes the math for anyone comparing Green against a self-built Raspberry Pi 5 setup — the DIY route's cost advantage is now larger than it used to be, even after adding a Zigbee dongle.

For most new buyers in 2026, Green is the simpler, currently-available choice. Yellow only makes sense if you already have a CM4/CM5 sitting around, or you specifically want the expandable NVMe storage and don't mind sourcing a discontinued product.

Recommended Upgrades / Best Accessories

If you already own a Yellow — or you're assembling one from remaining stock — these are the accessories that actually move the needle, based on where the recurring owner complaints cluster.

Storage: NVMe drives that don't crash the CM4

NVMe compatibility is the single biggest hardware headache reported by Yellow owners. Stick to drives with a confirmed track record rather than whatever's cheapest.

Crucial P3 500GB (CT500P3SSD8) — the budget, known-good pick. PCIe Gen3 x4, up to 3,500MB/s read, standard 2280 form factor.
Check Price on Amazon

Pros:

• Confirmed stable on the CM4 by the community
• Straightforward 2280 M.2 form factor
• Strong reliability track record

Cons:

• No standout endurance specs vs. NAS-rated drives

Verdict: The safe, no-drama choice if you just want the eMMC-to-NVMe upgrade to work the first time.
Perfect for: anyone moving off eMMC who wants a documented-compatible drive without overspending.

Samsung 970 EVO Plus 500GB (MZ-V7S500B/AM) — the mid-tier, widely-cited "good" drive.
Check Price on Amazon

Pros:

• On the community known-good compatibility list
• Strong warranty coverage
• Gen3 speeds match what the CM4's x1 link can actually use

Cons:

• Some other Samsung SKUs (980) have reported instability — model matters, don't assume the whole line behaves the same

Verdict: A reliable Gen3 pick; avoid the temptation to "upgrade" to a Gen4 drive, since the CM4's link can't use the extra bandwidth and Gen4 drives run hotter for no benefit here.
Perfect for: buyers who want a well-documented, higher-endurance option than the budget tier.

WD Red SN700 500GB (WDS500G1R0C) — the endurance pick for constant HA database writes.
Check Price on Amazon

Pros:

• NAS-rated for continuous read/write cycles
• High total-bytes-written rating for its class
• On the community compatibility list

Cons:

• Costs more than the budget option for a workload most homes won't fully exploit

Verdict: The right call if you're running a busy recorder database, long history retention, or heavy logbook writes and want a drive built for constant duty cycles.
Perfect for: power users worried about long-term write endurance rather than raw speed.

Power: keeping a PoE Yellow (and its data) alive

EnGenius EPA5006GAT PoE+ Injector — for anyone running the Yellow Kit PoE without a PoE-capable switch.
Check Price on Amazon

Pros:

• True 802.3at (PoE+) output, which the Yellow actually requires
• Simple single-port setup between switch and hub

Cons:

• One more inline device to route and label in a network closet

Verdict: If the Yellow won't power on over PoE, the injector (or the switch it's plugged into) not delivering true 802.3at is the most common cause — confirm the spec before troubleshooting further.
Perfect for: Yellow Kit PoE owners without a PoE+ switch port available.

CyberPower CP1500PFCLCD UPS — protects against the hard power loss that can corrupt eMMC or NVMe storage.
Check Price on Amazon

Pros:

• Line-interactive with pure sine wave output
• Integrates with Home Assistant over USB via NUT (Network UPS Tools)
• Enough outlets to cover the hub plus a switch or modem

Cons:

• Sized for a whole network rack, not just a single ~9W hub — overkill if you only need to protect the Yellow itself

Verdict: Worth it if the Yellow anchors your whole automation setup and a power blip taking down the database is a real risk; a smaller UPS will do if you're protecting the hub alone.
Perfect for: households where an unclean shutdown means lost automations, not just a reboot.

Frequently Asked Questions

Conclusion & Final Verdict

Home Assistant Yellow was a well-built, thoughtfully engineered hub for exactly the kind of reader this site is written for — someone who wants local control, an integrated Zigbee/Thread radio, and expandable storage without a subscription attached. That engineering hasn't gotten worse; what's changed is availability. It's discontinued, the Compute Modules it depends on are largely out of stock, and Nabu Casa itself is steering new buyers toward the Green.

If you already own a Yellow, this is still a hub worth maintaining: pair it with a known-good NVMe drive, keep an eye on Zigbee radio firmware updates before you apply them, and add a UPS if the hub anchors your whole automation setup. If you're starting from zero in 2026, the honest recommendation is to look at the Home Assistant Green for a plug-and-play setup, or a Raspberry Pi 5 build with a Connect ZBT-2 dongle if you want the DIY flexibility the Yellow used to represent — both are currently in production, and neither requires tracking down a discontinued compute module.