Hi. I am thinking about buying my first smart lights. Thinking about hue or tradfri. I searched on internet but I cannot find answer on: what happens with bulbs when I turn off bridge? Will they just work as normal bulbs? Can I still use dimming device or it works only when bridge is turned on. Will the bulb remember its dimming level, or it goes to max after turning off bridge?
On a Hue bridge the smart controls are paired with the bridge. That allows for more customisation but the switches cannot control the lights if the bridge is turned off.
On a Trådfri gateway the smart controls are paired directly with the lights. So they will keep working if the bridge is off. However, you cannot customise anything about the smart control configuration.
Of course you can always control the lights using non-smart switches. On a Philips Hue bridge you can change the power-on behaviour of lights: How to set up Power-on behaviour for my lights?. Trådfri lights will always switch on to previous state which cannot be changed.