Direct answer
Properly designed smart lighting should retain essential local control during an internet outage. Wall switches, dimmers, keypads, and locally processed scenes should continue when the lighting processor and local network remain powered. Remote access, offsite app control, cloud automations, and cloud-dependent voice assistants may be unavailable.
The exact result varies by product. Some consumer bulbs depend heavily on cloud services, while professional lighting systems generally emphasize local control. Ask whether schedules and scenes execute in a local processor, what happens if that processor fails, and whether each room retains usable physical controls. Power loss is separate; electronic controls still need electricity and should return to a defined state after restoration. Test internet loss, controller restart, and power restoration during commissioning.
How this answer was prepared
Camelback Smart Homes publishes this FAQ library for homeowners, design professionals, builders and property teams comparing integrated technology. Answers begin with the practical conclusion, then explain the factors that can change it.
Limitations: This is general educational information, not a site-specific design, quote, code determination or compatibility guarantee. Final requirements depend on the property, construction, infrastructure, equipment versions and project goals.