Free to download · Pro is $9.99 a year or $24.99 once · No account
Winter-first
No tanning, ever
Your data stays on your iPhone
10 languages
Soltide Pro
9:41
London
Next best light
Catch the Tide
Mon7
Tue8
Wed9
Thu10
Fri11
Sat12
Sun13
Mon14
Best light
Sky by hour
7:20
Next best light
—
Start
7:20
Your day
7:20
Soltidenow
Soltide Pro’s Today screen and the Apple Watch app, simplified. In the app, your best time and UV follow the live hourly forecast from Apple Weather.
A day with Soltide
Your iPhone plans the light. Your Apple Watch gets you out in it.
One winter day in New York — from the first look at the sky to the plan for your next trip. Screens from the app itself.
7:20
Soltidenow
7:20
Next best light · Morning
8:05–8:35 AM
30 min · ~14,000 lux
Start
7:20
Your day
Best light8:05–8:35 AM
Brightest half hour10:30–11:00 AM
Sunset4:28 PM
7:20
Soltidenow
7:20 AMPro
Wake up to one clear answer
Today shows your next best light, adjusted to the weather. With Pro you see the whole day around it: the sun’s path, the sky hour by hour and other good times. Your watch shows the same answer at a glance.
7:50 AMFree
A nudge before the light
One reminder, 15 minutes before your best light — on your iPhone and on your wrist. Never more than two a day.
8:05 AMFree
Catch the light from your wrist
Tap Start on Apple Watch and head out. The ring fills toward today’s light goal — grey days still count.
ProWith Pro, Apple Watch fills in your light log, and the daylight you log is saved to Apple Health.
12:45 PMPro
A sun-break alert
A sunny spell is forecast in your free time, so Soltide nudges you before it — the light grey days hide. It sees when you’re busy in Calendar and finds the light between meetings.
9:00 PMPro
See your light add up
Insights show your daylight over 30 and 90 days and when you get it, next to your sleep from Apple Health.
All winterFree
Made for the dark months
The Season tab follows the light through winter: daylight for the next two weeks, the next clock change, and then the light returning.
Before a tripPro
Plan ahead, even across time zones
Plan your best light up to 14 days out, with the weather. Flying? Get a day-by-day light plan for before and after the trip, and a gentle 3-day shift before the clocks change.
Try every Pro feature free for 7 days, then $9.99 a year.
The free days are for new subscribers to the yearly plan, which renews until you cancel. Cancel at least 24 hours before they end and nothing is charged. If notifications are on, we’ll remind you the evening before. You can check or cancel any time in Settings ▸ your name ▸ Subscriptions. Or pay $24.99 once for Lifetime, or carry on with the free app.
Your best light today
This is the sun engine from the app, running in your browser. Pick a place, when you wake up and the sky, and Soltide finds your window.
7:10–7:50
Estimates for open ground, not measurements; what reaches your eyes is usually lower. The app uses your own location and the live hourly forecast, and keeps the answer up to date through the day. Never look directly at the sun.
What is sunmaxxing?
The healthy version of the trend
Circadian sunmaxxing is the habit of getting outside within about an hour of waking, so natural daylight reaches your eyes. Soltide is built around the healthy version of the trend.
It’s about your eyes
Daylight reaching your eyes is the main signal that sets your body clock — helping you feel awake by day and sleepy at night.
Outdoors beats indoors
Even on an overcast day, outdoor light is usually 1,000 lux or more — several times brighter than a well-lit room (100–500 lux).
The first hours count most
Morning light matters most for your body clock. Later daylight may still help energy and mood — on grey winter days a lunch walk can be a good option.
Light, not a tan
Your skin doesn’t need UV for any of this. Soltide never sets tanning goals and shows you when to protect your skin.
Most sun apps are made for summer: UV, tanning, vitamin D. Soltide is made for the months when daylight is short, the mornings are dark and a grey sky hides the light — which is exactly when it’s hardest to get.
Weather-aware
Soltide lowers its light estimate for cloud and rain, hour by hour, and moves your window to where the light is.
Season-aware
Shrinking days, the clock change, the shortest day — and then the light returning, minute by minute.
Honest about vitamin D
When the sun is too low for your skin to make much vitamin D, Soltide says so plainly and points you to a doctor or pharmacist — not to more sun.
Free, every day
One clear answer, every morning
Next best light
The top of Today is one time window — like 7:10–7:50 — with how long to stay out and how bright it will be.
UV and safety, always free
When UV reaches 3, Soltide shows when to protect your skin. Safety information is never behind a paywall.
The season at a glance
Daylight for the days ahead, the next clock change, and the countdown to the shortest day.
Widgets and Apple Watch
Your next best light on the Home Screen, the Lock Screen and your wrist, with complications and a session timer.
A nudge when the light is right
One nudge a day, 15 minutes before your best light. Never more than two a day.
A gentle log
Start a session, or add 10, 20 or 30 minutes with a tap. A 7-day chart and a streak, without the guilt.
Soltide Pro
The coach that works in the background
Pay yearly, or once for good.
Sun-break alerts
A nudge when a sunny spell is forecast in your free time — the light grey days hide.
Your whole day
The sun’s path, the sky hour by hour, other good times and your day’s light plan, in one timeline.
Plans around your day
Soltide sees when you’re busy in Calendar and finds the light between meetings.
Travel and clock changes
A day-by-day light plan for new time zones, and a gentle 3-day shift before the clocks change.
Insights
Your light over weeks and months, next to your sleep from Apple Health.
Automatic tracking
Apple Watch fills in your light log, and the daylight you log is saved to Apple Health.
Plan two weeks ahead
Free plans today and tomorrow. Pro plans your best light, with the weather, up to 14 days out.
Today’s best light, UV and safety information, widgets and the session timer are always free.
$9.99 a year, or $24.99 once for Lifetime. The yearly plan starts with 7 days free for new subscribers, then it’s $9.99 a year unless you cancel at least 24 hours before the free days end. Lifetime has no free trial.
Free vs Pro
Free every day. Pro when you want the whole picture.
Feature
Free
Pro
Today’s best light, and why
Included
Included
UV, when to protect your skin, and all safety information
Included
Included
Plan today and tomorrow
Included
Included
Widgets, Live Activity and the Apple Watch app
Included
Included
Session timer, quick add, 7-day chart and streak
Included
Included
A reminder before your best light
Included
Included
Your whole day: sun arc, sky by hour, other good times, day plan
—Not included
Included
Sun-break alerts in your free time
A preview on Today
Included
Plan up to 14 days ahead, with the weather
—Not included
Included
Plans around your Calendar
—Not included
Included
Jet lag and clock-change light plans
A preview
Included
Insights: 30 and 90 days, next to your sleep
Your best day this week
Included
Apple Watch daylight tracking, saved to Apple Health
—Not included
Included
Price
Free
$9.99 a year or $24.99 once
Soltide Pro is $9.99 a year, renewing until you cancel, or $24.99 once for Lifetime.
New subscribers get the first 7 days of the yearly plan free, then it’s $9.99 a year unless you cancel at least 24 hours before they end. If notifications are on, Soltide reminds you the evening before. You can check or cancel any time in Settings ▸ your name ▸ Subscriptions.
US prices. The App Store shows the price for your country.
How Soltide works
Honest science, plainly said
The sun’s path
Soltide calculates where the sun is for your place and date, accurate to about two minutes for sunrise and sunset.
Estimated light
From the sun’s height, Soltide estimates outdoor light in lux, then lowers it for cloud and rain using the hourly forecast. These are estimates, not measurements.
Your best light
Soltide looks for a time you can actually get out to reach a light goal of about 30 minutes of bright outdoor light. The 30-minute goal is a habit target Soltide chose, borrowed from bright-light research — not a clinical dose.
Light, not UV
Your body clock responds to visible light at the eyes; UV does nothing for it. When UV is 3 or more, seek shade, cover up, wear sunglasses and use SPF 30+ — sunscreen isn’t a reason to stay out longer. No tanning goals, ever.
Sources: sun position — low-precision algorithm checked against NOAA’s Solar Calculator. Light — Haurwitz clear-sky model. UV — WHO Global Solar UV Index guide (2002) and Madronich (2007). Light timing — Brown et al., PLOS Biology (2022). Vitamin D — NHS and SACN guidance.
Soltide offers general wellness information, not medical advice. Light levels are estimates. If you have health concerns, talk to a doctor.
Privacy
Your light stays yours
No account, no ads, no tracking. Soltide works out the sun on your iPhone.
Your log stays on your iPhone
Your light log, settings and places are kept on your iPhone. Apple Health is read and written, and Calendar read, only on your devices — never sent anywhere.
Only an approximate area leaves
For the forecast, the app asks Apple Weather directly for an area about 10 km across — never your exact location. We run no servers for the app.
Nothing to sell
Soltide has no analytics, no advertising and no account. Soltide Pro pays for it.
Yes. Today’s and tomorrow’s best light, UV and all safety information, widgets, the Apple Watch app and the session timer are free. Soltide Pro — yearly (the first 7 days free for new subscribers, then $9.99 a year) or once for Lifetime — adds sun-break alerts, your whole day hour by hour (sun arc, sky by hour, day plan), calendar-aware plans, travel and clock-change coaching, Insights, automatic Apple Watch tracking and 14-day planning.
How much is Soltide Pro?
$9.99 a year, renewing automatically until you cancel, or $24.99 once for Lifetime. These are US prices; the App Store shows the price for your country. New subscribers get the first 7 days of the yearly plan free; after that it’s $9.99 a year unless you cancel at least 24 hours before the free days end. If notifications are on, Soltide reminds you the evening before. Lifetime has no free trial. Pro isn’t shared through Family Sharing.
What is sunmaxxing?
Circadian sunmaxxing is the habit of getting outside within about an hour of waking, so natural daylight reaches your eyes. Soltide is built around the healthy version of the trend. Your skin doesn’t need UV for any of this. Soltide never sets tanning goals and shows you when to protect your skin.
How long should I stay out in the morning light?
Soltide looks for a time you can actually get out to reach a light goal of about 30 minutes of bright outdoor light. The 30-minute goal is a habit target Soltide chose, borrowed from bright-light research — not a clinical dose. Even on an overcast day, outdoor light is usually 1,000 lux or more — several times brighter than a well-lit room (100–500 lux).
Is Soltide a biohacking app?
It’s the calm, evidence-based end of it. Soltide doesn’t sell supplements, gadgets or hacks: it finds the best time for daylight to reach your eyes, adjusted to the weather, and explains the science plainly. Daylight reaching your eyes is the main signal that sets your body clock — helping you feel awake by day and sleepy at night.
How do I cancel?
On your iPhone, open Settings ▸ [your name] ▸ Subscriptions ▸ Soltide Pro and tap Cancel Subscription, at least 24 hours before it renews. Pro stays on until the end of the year you’ve paid for. If you cancel during your free days, at least 24 hours before they end, nothing is charged. Lifetime never renews, so there’s nothing to cancel.
Do I need an Apple Watch?
No. Start a session or add minutes with a tap on your iPhone. With an Apple Watch, the Soltide watch app shows your next best light and a session timer, and with Pro your Time in Daylight from Apple Health fills in your log automatically.
Does it work on cloudy days and in winter?
That’s what it’s made for. Even on an overcast day, outdoor light is usually 1,000 lux or more — several times brighter than a well-lit room. Soltide uses the hourly forecast to find the brightest time you can get out, and tells you plainly when light is scarce.
Will Soltide help me tan or get vitamin D?
Soltide is about light reaching your eyes, not UV on your skin. It never sets tanning goals, and it shows you when UV is high enough to protect your skin. For vitamin D it says honestly when the sun is too low for your skin to make much, and points you to a doctor or pharmacist rather than to more sun.
Is Soltide medical advice?
No. Soltide offers general wellness information, not medical advice. Light levels are estimates. If you have health concerns, talk to a doctor — especially if you have bipolar disorder, an eye or retinal condition, take medicines that make you sensitive to light, or have had skin cancer.
What does Soltide know about me?
Very little. There’s no account. Your light log and settings stay on your iPhone, and Apple Health is read and written, and Calendar read, on the device only. For the forecast, the app asks Apple Weather directly for an approximate area — never your exact location. We run no servers for the app and receive none of your data. See the privacy policy.
Is there an Android version?
Not yet. Soltide is for iPhone and Apple Watch first.
The name
Why Soltide?
Sol
Latin for the sun.
tide
Daylight ebbs and flows like the sea: it rises every morning, shrinks towards the shortest day, then comes back.
Soltide helps you catch the light while it’s there. The weeks around the shortest day are low tide — and after them, the light is returning. The logo says it too: a rising sun above a wave.
The days are getting shorter. Catch the light you have.
