mmWave vs. Wi-Fi Sensing - Community Guides - Home Assistant Community = 40rem)" rel="stylesheet" data-target="desktop" /> = 40rem)" rel="stylesheet" data-target="chat_desktop" /> = 40rem)" rel="stylesheet" data-target="discourse-ai_desktop" /> = 40rem)" rel="stylesheet" data-target="discourse-reactions_desktop" /> = 40rem)" rel="stylesheet" data-target="poll_desktop" /> = 40rem)" rel="stylesheet" data-target="desktop_theme" data-theme-id="19" data-theme-name="scroll to top"/> mmWave vs. Wi-Fi Sensing Community Guides cookbook mike2872 (Mike) May 18, 2026, 12:12pm 1 Hey everyone, As some of you may know a handful of Wi-Fi Sensing projects have started emerging with Home Assistant support. I'm working on one of them and naturally have a strong interest in the field. The primary option for presence detection has long been mmWave, where Wi-Fi Sensing has primarily been a research area. But this past year multiple projects have arisen where this technology can actually be used in non-lab environments. For my own projects and home setup, I'm using a combination of Wi-Fi Sensing and mmWave, and I thought I would create a comparison between these two technologies, to give you an idea of the strengths and weaknesses of both. I'm not going to go deep into how each technology works. That is for another post. But the short version is that Wi-Fi Sensing works by analyzing how existing Wi-Fi packets are being affected by humans (we are mostly water and therefore affect the signal a lot) to detect presence. Humans affect mmWave in roughly the same way, but instead of Wi-Fi packets they use a dedicated sensing network, usually at much higher frequencies (10-100GHz). This means that Wi-Fi Sensing can be added to existing Wi-Fi devices as a software-only add-on, where mmWave are dedicated sensors you have to buy separately. Hardware mmWave sensors are dedicated hardware. People in this community usually go for LD-2410, LD-2450, Aqara FP2, Everything Presence One etc. Wi-Fi Sensing can be added to existing Wi-Fi devices, but the current projects only support devices where it's possible to extract Channel State Information (CSI), which is the part of the Wi-Fi packets that are analyzed. Currently, the most practical devices to extract CSI from are ESP32s. This is fortunate since ESP32s are extremely cheap, and many people in the HA community already have a lot of these deployed at home (e.g. ESPHome projects). The Wi-Fi Sensing projects today typically work as an external ESPHome component and/or provide flash tools for easy one-click flashing of ESP32s. Range and coverage Most mmWave devices for smart homes are typically effective between 6-10 meters. The range of Wi-Fi Sensing is much higher, usually 10-30+ meters and primarily limited by how far the devices can maintain a strong Wi-Fi connection. Through-wall capabilities mmWave operates at frequencies that mostly render it unusable when passing through one or more walls, especially thicker ones. Wi-Fi Sensing operates at frequencies that were specifically engineered to propagate through walls and often works through multiple thick walls. Localization and zoning In order to do localization you need to be able to determine the direction of the part of the signal being received, which requires multiple phase-coherent antennas. You also need to determine how far the signal travelled, which is limited by the bandwidth of the device. mmWave devices all have multiple TX/RX antenna pairs with broad bandwidth which allows very precise zoning. This means you are able to create tight zones such as only detecting presence at a desk. Wi-Fi Sensing is theoretically able to do the same when using devices with multiple antennas with broad bandwidth (e.g. a router with 160MHz bandwidth), but current ESP32s only have single antennas and use 20/40MHz. In theory this means Wi-Fi Sensing is not able to do localization, although in practice, zoning is done indirectly by creating a mesh of ESP32s and performing some averaging tricks to achieve rough zoning. The new ESP32-E22 (announced, unknown release date) is the first to have two phase-coherent antennas and support 160MHz. That changes things, and we are therefore going to see proper localization implemented in Wi-Fi Sensing projects in the near future. Right now mmWave has the tightest zoning, but Wi-Fi Sensing still does it fairly well for room-level localization and is going to catch up soon. Deployment and pricing The fact that the Wi-Fi Sensing projects today are software-only and use ESP32 means that presence detection can be added to a home for a few bucks, or even added to ESPHome devices already deployed around your house using an external ESPHome component. The fact that these devices are already in your home removes the need for dedicated devices to do presence detection. The through-wall capabilities also mean that devices can be hidden in drawers, closets or even inside walls (e.g. install the ESPHome component on a Shelly relay). As a conclusion I think Wi-Fi Sensing today has an edge in range, price and ease of deployment, where mmWave has the best zoning capabilities. But in the near future when it's feasible to implement localization on ESP32s (or if other devices come out with easy CSI extraction), I think the edge of mmWave's zoning is going to disappear. I'm going to list all the projects I know that do Wi-Fi Sensing for those of you who want to try it out. If I'm missing any, just let me know and I'll edit this post: Projects (alphabetical order, as per 18 May 2026): ESPectre (open source, ESP32, Home Assistant, ESPHome) Philips Hue MotionAware (closed source, Hue ecosystem). Strictly not Wi-Fi Sensing as it's using ZigBee. RuView (open source, multiple devices). Some list this as a non-functioning project using placeholder data. I don't know but I'll keep it for fairness. TOMMY (closed source, ESP32, Home Assistant, ESPHome). Disclaimer : my project. Xfinity WiFi Motion (closed source, works only on Xfinity routers) Note: I have used an LLM to fix typos and grammar mistakes in this post. 1 Like bartkummel (Bart Kummel) May 18, 2026, 2:23pm 2 Interesting. I've done a quick compare of ESPectre and TOMMY. As far as I understand, TOMMY is the only one of the two that can detect presence rather than only motion. I.o.w.: it can also detect whether someone is present that is sitting or standing still. That's exactly the only reason to choose a mmWave sensor over a classic (and cheap) PIR sensor. That said, if I understand correctly, for TOMMY to work correctly, you need at least two devices and they need to be at opposite sides of the area you want detection for. I think that's a major drawback compared to mmWave devices. With a mmWave sensor, I can tuck it away in a corner easily, especially given that there are now battery-powered mmWave sensors. Having to place a (potentially AC-powered) device in at least two corners makes it harder to place the devices. Although you mention that you can use existing devices, those are often not in the correct location for detection. mike2872 (Mike) May 18, 2026, 4:38pm 3 I'm not entirely sure if ESPectre supports some kind of presence detection, so I'd rather not say yes or no. But last time I checked it didn't. You are right in the fact that you need at least 2 devices (preferably opposite sides). That is definitely a drawback if you don't happen to have either two existing ESPHome devices at those locations or the option to install it. That's also why I use mmWave for some rooms in my home. But that drawback turns into a positive if your aim is to detect presence in larger zones (or multi-room zones) given the larger range and through-wall capabilities. This means you could have 2 devices span a whole apartment, a floor, a section of your house spanning multiple rooms etc. You might not care about room level precision in your garage for example. bartkummel (Bart Kummel) May 19, 2026, 5:51am 4 Thanks for confirming. It makes sense, both technologies have their pros and cons and hence different use cases require different technologies. 1 Like francescopace (Francesco Pace (ESPectre)) June 10, 2026, 12:57pm 5 Thanks to @mike2872 as well for the analysis, I think it is fair and accurate overall. @bartkummel ESPectre does not expose presence yet, only motion. In the CSI world, “presence” is often closer to detecting very small motion, like breathing or other micro-movements, so in practice it comes down to finding a reliable threshold and validating it properly. I’m planning to add a presence sensor in ESPectre v3, and, if the test results are solid enough, possibly also a breathing indicator. I’d rather be cautious than overpromise, so I’m spending time on testing and fine-tuning first, but yes, it’s definitely on the roadmap. And yes, I also agree with the broader comparison: mmWave is currently the easier choice if you want a mature, straightforward presence sensor, but Wi-Fi sensing is a much more exploratory field. That is also part of what makes it fun for me: there is still a lot to discover! Tech1977 August 5, 2026, 10:12am 6 Hi everyone, I have a specific use case and I’m wondering if Wi-Fi Sensing (CSI) could be the solution, given its through-wall capabilities mentioned here. Is it actually possible to reliably detect human presence outside a perimeter wall using devices placed indoors? My goal is to detect if an intruder is approaching my ground-floor windows and patio doors (I have about 5 meters of completely clear, open space outside the walls) before they actually touch or try to force the frame. I don’t want to install any visible sensors or cameras on the outside facade for aesthetic and privacy reasons. Furthermore, I want to avoid any masonry work or complex wiring, and above all, I want to avoid outdoor sensors altogether because they are highly prone to false positives caused by weather, animals, or environmental changes. Do you think a multi-device Wi-Fi sensing setup (like ESP32 nodes running CSI tools) placed safely indoors could bounce signals through an external brick/concrete wall and pick up someone walking in that open outdoor area? Or would the outdoor environment (wind, rain, open space dispersion) still ruin the reliability of the CSI data? Would love to hear if anyone has attempted something similar for pre-intrusion perimeter detection! tmjpugh (Tmjpugh) August 6, 2026, 2:27am 7 WiFi sensing works well. WiFi does not work well through walls. Worse through concrete/brick