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Home Assistant Yellow
The enthusiast-grade HA hardware with CM4 compute module, built-in Zigbee/Thread radio, NVMe SSD support, and PoE capability.
Check Price on AmazonOverview
The Home Assistant Yellow is Nabu Casa's enthusiast-tier hardware platform — a step above the plug-and-play HA Green, designed for users who want more power, more connectivity, and more flexibility. Where the Green is a sealed appliance optimized for simplicity, the Yellow is an open platform built around the Raspberry Pi Compute Module 4 (CM4) that invites expansion and customization.
Released in 2023 and still the go-to recommendation for serious HA users in 2025, the Yellow hits a compelling sweet spot: it's purpose-built for Home Assistant, includes a built-in Zigbee/Thread radio, supports NVMe SSDs for fast storage, and offers Power-over-Ethernet for clean cable management. It's the hardware we'd buy if starting fresh today.
Specs & Hardware
| Spec | HA Yellow (Standard) | HA Yellow (PoE) |
|---|---|---|
| Compute | RPi CM4 (2GB RAM, 16GB eMMC) | RPi CM4 (2GB RAM, 16GB eMMC) |
| Storage | eMMC + M.2 NVMe slot | eMMC + M.2 NVMe slot |
| Wireless Radio | Zigbee/Thread (Silicon Labs) | Zigbee/Thread (Silicon Labs) |
| Power | USB-C | 802.3at PoE |
| Ethernet | Gigabit | Gigabit |
| USB | 2× USB-A | 2× USB-A |
| GPIO | 40-pin RPi header | 40-pin RPi header |
The CM4 inside is a proper quad-core Cortex-A72 processor — significantly more capable than the older Raspberry Pi 3 that many HA users still run. The 2GB RAM handles Home Assistant comfortably, and you can upgrade to a CM4 with 4GB or 8GB RAM for demanding setups (though sourcing specific CM4 variants can still be tricky).
The M.2 slot is a highlight. Popping in a 250GB NVMe SSD (around $25–30) dramatically improves database performance — HA's recorder creates substantial write load that SD cards struggle with over time. NVMe eliminates that concern entirely.
Performance
In daily use, the Yellow feels snappy. Dashboard loads, automation execution, and integration polling all feel immediate. We compared startup times against an older Raspberry Pi 4 (4GB, SSD) running HA, and the Yellow is competitive — the CM4's tighter integration with the board yields slightly better thermal performance, meaning it sustains performance better during long uptimes.
HA OS boots in approximately 25–35 seconds on the included eMMC storage. With an NVMe SSD, this drops to under 20 seconds and database operations feel noticeably faster. If you're running many integrations, heavy automations, or the Frigate NVR add-on for camera processing, the NVMe upgrade is essentially mandatory.
Thermal performance is excellent. The Yellow includes passive cooling with a properly designed heat spreader. We never saw CPU throttling under normal HA workloads. The board runs warm to the touch but not hot.
Built-in Zigbee & Thread Radio
This is where the Yellow genuinely shines over DIY setups. The Silicon Labs MGM210P multiprotocol radio module handles both Zigbee and Thread/Matter protocols simultaneously. No USB Zigbee dongle needed. No USB controller interference. No physical placement trade-offs.
The radio works seamlessly with the ZHA (Zigbee Home Automation) integration built into HA, as well as Zigbee2MQTT. Pairing new Zigbee devices was smooth and reliable in our testing. Signal strength was solid — the Yellow was in a central location and reached Zigbee devices throughout our test home without issues.
Thread support positions the Yellow well for Matter, the new smart home connectivity standard. As more Matter-over-Thread devices appear on the market, having a proper Thread border router built in is a real advantage.
Yellow vs Green: Key Differences
| Feature | HA Green | HA Yellow |
|---|---|---|
| Price | ~$99 | ~$149–$199 |
| Setup Simplicity | Plug and play | Easy (some assembly) |
| Storage | 32GB eMMC only | eMMC + NVMe SSD |
| RAM | 4GB (fixed) | Upgradeable CM4 |
| Built-in Radio | None | Zigbee + Thread |
| PoE Option | No | Yes |
| GPIO Header | No | Yes |
| Expandability | Sealed | High |
Who Should Buy It?
The Yellow is the right choice if:
- You use or plan to use Zigbee devices (the built-in radio is a genuine quality-of-life upgrade)
- You want NVMe storage for long-term reliability and database performance
- You run a power-hungry setup (Frigate, many add-ons, heavy automations)
- You want PoE for a clean installation without a separate power adapter
- You're building a permanent, long-term HA installation
Stick with the Green if:
- You want the simplest possible setup with zero assembly
- You're just getting started with HA and aren't sure you'll stick with it
- You don't use Zigbee devices and don't plan to
- Budget is the primary concern
Verdict: 9/10
The Home Assistant Yellow is the best purpose-built hardware for serious Home Assistant users. The built-in Zigbee/Thread radio, NVMe storage support, and PoE option make it significantly more capable than the HA Green for anyone running a substantial smart home setup. At around $150–$200 depending on configuration, it's not cheap, but it's worth every dollar if you're building a permanent installation. Highly recommended.
Home Assistant Yellow
Purpose-built HA hardware with built-in Zigbee/Thread, NVMe support, PoE, and a Raspberry Pi CM4 compute module.
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