The smart, simple way to get enough sun without burning.

HELLO SUN

Real-time vitamin D estimates and sun + supplement tracking, with conservative burn-risk guidance. Personalized to your skin type and location. No ads. No data selling.

Safety & Privacy First • Weekly Status • Acclimation

Hello Sun session timer screen showing UV index, goal progress, and burn-safe session controls

Know Your Burn Time

Real-time burn countdown + safety zones while you’re in the sun. Built to be conservative, so you can get vitamin D without flirting with a burn.

Catch The Best Window

See your “best windows” for vitamin D. Time blocks where UV is moderate and safer for your skin type, so you can plan instead of guessing.

Hello Sun planner screen showing UV forecast graph and best window for safe sun exposure
Hello Sun progress screen showing weekly vitamin D chart, sun style insight, and achievements

Track your Progress

See your weekly vitamin D status over time, built around a 7-day momentum, so you can spot what’s working fast.

Adapts to your skin

Hello Sun learns your real-world tolerance and adjusts your safe limits over time and if you mark a burn, it automatically switches into a temporary “be extra gentle” recovery mode with shorter, safer recommendations while you bounce back.

Hello Sun app showing Recovery Mode info and an acclimation percentage chart over time
Hello Sun app progress dashboard showing sun points, levels, and weekly consistency metrics

Lifetime Progress Insights

Get a big-picture view with lifetime stats like Level, Sun Points, streak, and momentum, plus deeper history views as you build more data.

Low UV? Stay on track

When UV is too low for vitamin D production, Hello Sun helps you stay consistent anyway—plan smarter, lean on supplements, and keep weekly momentum through winter gaps.

Hello Sun winter mode screen showing vitamin D total, goal progress, and supplement logging

Safety-first sunshine, built on trust.

Real-time vitamin D estimates with adaptive safe limits and burn-risk guidance—personalized to your skin and location. Stored locally, ad-free, and designed for real life.

Estimates are guidance, not medical advice.

© Hello Sun 2026 • [email protected]