Home Assistant is a free, open-source home automation platform that runs locally on a user's own hardware rather than in a manufacturer's cloud. The project was started in 2013 by Paulus Schoutsen; Nabu Casa, Inc., founded in 2018 by Schoutsen and Pascal Vizeli in Irvine, California, now stewards development and funds the project through an optional cloud subscription.
Home Assistant integrates with well over 2,000 smart home brands and protocols, including Zigbee, Z-Wave, Matter, and Thread devices, letting users create dashboards, automations, and scripts that combine devices from different manufacturers regardless of whether those brands work with each other natively. Because it runs locally (typically on a Raspberry Pi, mini PC, or dedicated Home Assistant hardware), it can continue operating without an internet connection, and its "Assist" voice feature offers a local, privacy-focused alternative to cloud voice assistants.
It is aimed at technically inclined users and smart home enthusiasts who want maximum device compatibility, local control, and privacy rather than being locked into a single vendor's ecosystem, though its companion apps make everyday use straightforward for less technical household members too.
The software itself is free and open source. Nabu Casa's optional Home Assistant Cloud subscription (about $6.50/month or $65/year) adds secure remote access, cloud backups, and voice assistant integrations. Companion apps are available on iOS, Android, and the web.