It's not really a night light. More like a before-bed and wake-up light.

While they don't publish the brightness, I asked Casper support, and they said it is about 375 lumens, which seems right anecdotally (I don't have an integrating sphere to verify). Note that you need to open the app and set "Overall Brightness" to max (just one time, not every time) to get that many lumens, otherwise, it's more like 300.

That's roughly equivalent to a 40 Watt light bulb. 100-150 lux at a usable distance (which is what this would give you) is a good setting for most people (from what I've seen). For my eyes (age 26) that's plenty to read with.