比例スケールツール
幅または高さに基づいて一括スケールし、もう一方はソース画像の比率から計算されます。
比例スケールツール
画像をアップロード
画像をここにドロップするか、クリックしてファイルを選択
一括アップロードに対応しています
エクスポート
結果はまだありません
About This Proportional Resize Tool
Proportional scaling is useful when you need to shrink or enlarge images by width or height while keeping the original aspect ratio. It is a clean workflow for oversized source files, upload preparation, and faster-loading web graphics.
Useful for shrinking oversized originals
A common task is turning something like 12000 x 10000 into 1200 x 1000 without adding padding or cropping. This tool is designed for exactly that kind of ratio-safe resizing.
Useful for upload dimension limits
Many publishing tools, forms, and marketplaces have limits on image dimensions or file size. Scaling by width or height helps bring assets closer to those constraints before export.
Useful for web performance workflows
For article images, resource libraries, and landing page graphics, reducing pixel dimensions before compression often creates better final performance than relying on quality compression alone.
Proportional Resize FAQ
These questions usually matter most when preparing images for websites, uploads, and performance-sensitive pages.
What is the difference between scaling by width and scaling by height?
When you scale by width, you set the target width and the tool calculates the height automatically. When you scale by height, it does the reverse. In both cases the original aspect ratio is preserved.
Can proportional resizing stretch an image?
No. The tool always calculates the second dimension from the source aspect ratio, so the output stays proportional and the image is not stretched into a different shape.
When should I avoid upscaling an image?
If the source image already has limited pixel detail, enlarging it will usually make edges softer and artifacts more visible. In most web workflows, shrinking is safer than enlarging unless a larger output is absolutely required.