Suihei | Pro Photo Leveling
Auto-leveling + manual rotate
Only for Mac
Free · In‑App Purchases
Mac
Straighten and crop crooked shots one photo at a time — fully non-destructive. Built for photographers who process many frames by keyboard.
Suihei levels crooked photos automatically — one image at a time — then crops to a clean rectangle with no leftover corners.
It does two things and nothing else: rotate to horizon, and inscribe-crop. No exposure, no color, no clutter.
WHAT IT DOES
• Per-image tilt estimate. Each photo is analyzed on its own — no single value forced across a whole batch.
• Two estimation methods: AI, the recommended built-in estimator, and Vision, a non-AI multi-detector option for photos where AI does not look right. Both run on your Mac; photos are not uploaded, and AI does not learn from your photos or edits while you use it.
• Zero-margin inscribed crop: the largest upright rectangle that fits, with no transparent edges.
• Non-destructive. Your originals are never modified; corrected copies are written to a separate location, with EXIF preserved.
A KEYBOARD-FIRST WORKFLOW
Built for professionals working through many frames: overview, quick per-photo tweak, export — mostly without leaving the keyboard.
• Fine rotation with [ and ], faster steps with ⇧[ and ⇧].
• Leveling tool (⌘L): drag along any line in the image and Suihei rotates it to the nearest axis.
• Move the crop with ⌥ + arrow keys, resize with ⌘↑ / ⌘↓.
• Multi-step undo and redo. Save and restore your session.
DESIGNED FOR macOS
• Built with SwiftUI, Vision, Core Image and Core ML — no third-party engines.
• Photo processing stays on your Mac and works offline. Sandboxed: it never writes to your source folder.
REQUIREMENTS
macOS 26.4 or later, Apple Silicon.
Unlock Exports is a one-time purchase, not a subscription. The first 300 success fully exported photos are free. If a selection exceeds the remaining allowance,
you can export the allowed photos first in library order or unlock exports. Multiple windows share the same allowance and cannot exceed 300. Viewing and editing stay fully available after the allowance is used.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, MARGINAL GAINS INC., 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
- MARGINAL GAINS INC.
- Size
- 13.3 MB
- Category
- Photo & Video
- Compatibility
Requires macOS 26.4 or later.
- Mac
Requires macOS 26.4 or later.
- Mac
- Languages
- English and Japanese
- Age Rating
13+
- 13+
- In-App Purchases
Yes
- Full Version (Unlock Export) $24.99
- Copyright
- © 2026 MarginalGains, Inc.