The fourth dimension of route planning

You picked the route.
We'll pick the

Open a GPX — or share one straight from Strava, komoot or Garmin Connect — pick a date, and loop4d walks the sun across your whole route, point by point. Shade on a hot summer day, sun in winter, wind and twilight in between.

Free on theApp Store

Scan with your iPhone

Per-pointsun & shade

On-deviceno account

FreeiPhone

loop4d showing a 39 km road cycling route with its best-in-shade window, 05:35 to 07:33, and a full-day shade and temperature chart

How it works

One day of sun, walked across your route.

For every point of your track, loop4d works out when the sun clears the ridges, trees and buildings around you — then folds in the forecast.

Per-point sun & shade

Ridges, tree canopy and buildings, computed from open elevation data — right on your phone.

Best windows

Clear "best in shade" and "best in sun" slots for your day — and the window to avoid.

Weather & wind

Temperature, rain, headwind and tailwind, twilight — from a live forecast for your date.

Replay

Scrub through the day and watch the route light up shade, sun and wind, segment by segment. No route handy? Grab the sample GPX.

In the app

The whole day, on one screen.

loop4d planner: choose a GPX file, pick a date, seek shade or seek sun — **Plan**Pick a date. Seek shade or seek sun.

Route analysis with best-in-shade window and day chart of canopy, terrain shade, temperature and wind — **Analyze**Your best window, with the full day chart.

Map view with the route coloured by shade and sun at 20:15, with a replay slider — **Replay**Scrub the day — the map recolours live.

Ranked time windows: best overall 65% in shade, alternatives, and a midday window marked avoid — **Compare**Ranked windows — and the one to avoid.

loop4d home screen in dark mode — **Night**Dark mode for pre-dawn starts.

Connected to Strava New in 1.1

Your Strava routes, one tap away.

Connect your Strava account once and skip the GPX shuffle — then let loop4d close the loop after the ride.

Browse your routes

Pick any saved Strava route and analyze it directly — no export, no file juggling.

Get the nudge

When your activity lands on Strava, loop4d notifies you — tap to open it.

See what you got

How much sun and shade you actually rode through — then share your ride card.

Optional — loop4d works fully without an account. Connecting uses Strava's official sign-in; disconnect any time.

Runs on your deviceRoutes are analyzed right on your iPhone. loop4d only fetches public elevation and weather data to do the math.

No account, no sign-inOpen a GPX and go. An account exists only if you choose to connect Strava.

Fast after the first lookFirst analysis of a new area downloads terrain once — re-runs of the same area are instant.

Free · iPhone

Know your hour before you head out.