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.

Join the Waitlist

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.

Track your Progress

See your weekly vitamin D status over time, built around a 7-day rhythm (not daily perfection) 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.

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.

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.