UV Index – Sundoze

New: Supplement logging is now free — plus a weekly summary in Insights and a free UV widget. Pro unlocks your unlimited history and all widgets.

Sun, smarter.

Sundoze tells you the right amount of sun for vitamin D, a safe day out, or a steady tan — adjusted for your skin type, the altitude you're at, and where in the world you are.

Most UV index apps pick a side. Sundoze has two modes for two real sun goals:

▸ MORE SUN — when you're chasing vitamin D or a steady tan. We show you the safe window before you burn. No moralizing. No "just stay inside."

▸ LESS SUN — when you just want to be outside without skin damage. We track your burn time, remind you to reapply SPF, and quietly add it up over the season.

▸ TRAVEL MODE Going somewhere new? Sundoze shows exactly how the UV index compares to home — adjusted for your skin type. "Phoenix runs hotter than home — pack SPF 50+" isn't generic advice. It's your skin, your math.

▸ ALTITUDE MATH UV intensifies about 12% per 1000 m of elevation. Snow reflects up to 94%. Most apps don't correct for this. Sundoze does. Built for the Alps and Rockies, not just the beach.

▸ WINTER MODE Northern winters mean the UV index is too low for vitamin D from sun alone. Sundoze switches into supplement-tracking mode automatically. 80% of Europeans are insufficient through winter. We help you stay consistent.

▸ SCIENCE Burn-time math uses the Fitzpatrick I–VI skin-type system. Calibrated against the same research dermatologists use. Not generic warnings — your skin, your numbers.

▸ DESIGN Editorial typography, calm palette, no doomscroll, no panic colors. Sundoze is built to be glanceable in bright sun.

▸ PRO Unlocks unlimited Travel cities, full Winter Mode tracking, and the 7-day UV index forecast for every location. Free trial included.

Built in Switzerland. No ads. No tracking. Just the math.

Terms of Use: https://arytec.ch/sundoze/terms Privacy Policy: https://arytec.ch/sundoze/privacy