Chrome Extension

When you browse a climbing route or area on theCrag.com, the extension automatically shows today's sun and shade times — right on the page.

If a route doesn't have a shade profile in our system, nothing is shown. The extension is completely invisible on unsupported routes.

A panel appears showing:

• Sun intervals — when direct sunlight hits the route (e.g. 09:51 – 15:35)
• Total sun and shade hours for the day
• Timeline bar with a red “now” marker so you can see at a glance whether the route is currently in sun or shade
• Link to the full sky chart on Lost In Kalymnos for detailed analysis

When you visit a crag/area page, you get an overview of all routes with shade profiles:

• Shade summary — when shade is available across the crag
• “Best shade” bar — shows the maximum shade you can get by moving between routes during the day
• Individual route bars with names and sun times
• Link to the crag overview on Lost In Kalymnos

1. Download the extension from GitHub — click the green Code button, then Download ZIP
2. Unzip the downloaded file
3. Open Chrome and go to chrome://extensions
4. Enable Developer mode (toggle in the top-right corner)
5. Click Load unpacked and select the unzipped folder
6. Browse any route or area on theCrag — the shade panel appears automatically

The extension fetches route data from the Lost In Kalymnos shade calculator and computes sun/shade times for today using terrain profiles captured from the actual climbing locations.

Each terrain profile maps out the mountains, cliffs, and ridges that block the sun — so you get accurate shade times specific to each route, not just generic sunrise/sunset.

The profiles are captured using our companion Android app, which uses AR to trace the skyline from the base of each route.

Only a handful of crags have shade profiles so far. To see the extension in action, try this area page on theCrag:

Sabaton — Leonidio on theCrag

You can also browse individual routes within that area to see the single-route shade panel.

The shade calculator is currently being tested in Leonidio, Greece, with profiles being added as climbers contribute them using the companion Android app.

We plan to do a comprehensive profile-building session in Kalymnos, Greece starting April 2026.

See all available routes on the Shade Calculator.