Sunlight Checker: Sun & Shadow
Sunlight hours for Japan homes
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
NEW: Tap a building to see its height, storeys, zoning, coverage and floor-area ratios, and flood risk — alongside real sunlight hours. Check homes before you visit.
Will your next home actually get sunlight? "South-facing" on the listing doesn't tell you what the buildings around it do to the sun.
Sunlight Checker computes real sunlight hours for any address in Japan's major cities. Tap the map and it simulates the sun's path for all 12 months, using the Japanese government's official PLATEAU 3D city model to account for shadows cast by every surrounding building.
FREE FEATURES
- Sunlight hours per month and yearly average, scored S to D
- Floor selector — see how sunlight changes from the 1st to the top floor
- Building details: height, storeys, zoning, building-coverage ratio, floor-area ratio, flood and landslide risk (PLATEAU attributes, availability varies by city)
- Save up to 1,000 favorite locations
PRO FEATURES
- Hourly timeline in 15-minute steps
- 3D shadow visualization
- Direction filter (south-facing windows only, etc.)
COVERAGE
Tokyo 23 wards, Yokohama, Kawasaki, Osaka, Nagoya, Fukuoka, Sapporo, Saitama and other major cities.
PRIVACY
All computation happens on your device. Searched addresses are never sent to a server.
Note: The app interface is currently Japanese only. The map and numeric results are easy to follow, and this page's screenshots show exactly what you'll see.
Privacy policy: https://sunlightchecker.remosia.biz/privacy.html
Terms: https://sunlightchecker.remosia.biz/terms.html
Building data: Ministry of Land, Infrastructure, Transport and Tourism (MLIT) PLATEAU, adapted (https://www.mlit.go.jp/plateau/)
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
NEW: Building details (free)
Tap the building badge on a result to see the building's specs — height, storeys, usage, zoning, building-coverage and floor-area ratios, plus river-flood, storm-surge and landslide risk from Japan's official PLATEAU data. Attribute availability varies by city.
IMPROVED & FIXED
- Fixed a subtle sunlight-time offset on devices set to a non-Gregorian calendar (e.g. Japanese calendar)
- Fixed an error where building data could not be found in some areas (e.g. Osaka, Kobe, Fuchu in Hiroshima)
- More stable sheet presentation
The developer, 株式会社リモシア, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- REMOSIA, K.K.
- Size
- 10 MB
- Category
- Utilities
- Compatibility
Requires iOS 26.2 or later.
- iPhone
Requires iOS 26.2 or later. - iPad
Requires iPadOS 26.2 or later. - Mac
Requires macOS 26.2 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.2 or later.
- iPhone
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- 年額プラン（お得） $14.99
- 月額プラン $1.99
- Copyright
- © 2026 Remosia Co., Ltd.