Is your plant getting enough light? It’s the question behind most struggling houseplants, and it’s hard to judge by eye: a spot that looks bright to us can be far too dim for a fiddle leaf fig. LumiLeaf is a free Android app that turns your phone into a simple plant light meter. Hold it where your plant’s leaves are, screen facing the window, and get a plain-English answer in seconds.
LumiLeaf is made by Revenus Media.
Coming soon to Google Play.
How the plant light meter works
- Your phone’s light sensor (the one that adjusts screen brightness) measures the light where you hold it.
- LumiLeaf tells you what that means: too dark, low light, medium light, bright indirect light or direct sun, with the lux and foot-candle numbers underneath.
- Choose your plant from over 100 common houseplants and see straight away whether the spot suits it: “Great spot for a Snake Plant” or “Too dark for a Fiddle Leaf Fig”.
- Each plant’s light needs are based on published guidance from university extension services.
Which plants need bright light?
Light needs vary a lot between houseplants. Cacti, succulents, fiddle leaf figs and citrus want bright light with some direct sun for much of the day. Monsteras, pothos and philodendrons are happy in bright indirect light near a window, out of harsh midday sun. Snake plants, ZZ plants and cast iron plants cope with low light, which is why they suit hallways and north-facing rooms.
Light also drops quickly as you move away from a window: a shelf a couple of metres back can get only a small fraction of the light on the windowsill, even though it looks bright to you. A plant light meter takes the guesswork out, so you can match each plant to a spot that suits it.
Find the best spot in your home
- Save spots like “Lounge window”, “Bedroom shelf” or “Kitchen sill” and compare them side by side.
- Too dark? Get practical tips to brighten a spot, and grow-light ideas if a window isn’t enough.
- Lux or foot-candles, light and dark mode, and calibration if you own a reference light meter.
Measure all day
- Leave your phone by the plant, plugged in, and LumiLeaf records the light every minute.
- The screen goes almost black while it measures, and logging stops by itself if the battery runs low or the phone gets too hot.
- Afterwards you get a day report: a light curve, the brightest hour, hours at each light level, and an estimated Daily Light Integral (DLI) compared with your plant’s needs.
- Export the readings as a CSV spreadsheet.
Private and free
- No account and no sign-up. Your readings, spots and logs stay on your phone; nothing is uploaded.
- No subscription and no in-app purchases. LumiLeaf is free thanks to ads: small banners on some screens, and a short optional video to unlock “Measure all day” or a CSV export.
- Uninstalling the app deletes everything it stored.
Read the full LumiLeaf privacy policy.
Questions and support
Email onlineaop+lumileaf@gmail.com. We aim to reply within a few days.
LumiLeaf estimates light using your phone’s ambient light sensor. Phone sensors aren’t lab instruments and differ between models, so readings are best for comparing spots and judging light levels rather than as professional measurements. Some phones don’t share light-sensor readings with apps; LumiLeaf tells you if yours is one of them. Shop links in the app may be affiliate links: we may earn a commission from purchases made through them.
