Online Image Resizer
画像の幅と高さをピクセル単位で正確に調整できます。アスペクト比を維持したリサイズや指定比率の切り抜きに対応。
Drop images here
Supports JPG, PNG, WebP and other formats
Why Use the Image Resizer
Precise Control
Set exact width and height values, with support for proportional scaling or custom dimensions.
Keep Proportions
Automatically maintain aspect ratio to prevent image distortion.
Fast Processing
Leveraging Canvas technology for millisecond-fast processing.
Batch Processing
Resize multiple images simultaneously to improve your workflow.
How to Resize Images Online Free
Drop Your Images
Click the upload area or drag images into the browser. This image resizer works with JPG, PNG, WebP, and other common formats. Upload multiple files for batch processing. A single photo or an entire collection — no problem. Everything stays local in your browser, private and secure. No file size limits either, so high-res camera shots are fine.
Set Dimensions and Preserve Proportions
Enter width and height values, or pick from presets like 1920x1080 (Full HD), 1280x720 (HD), 800x600, or 400x400 (square). The aspect ratio lock keeps images from distorting — enter one dimension and the other adjusts automatically. You can also change the output format at the same time, converting to JPG, PNG, or WebP while resizing. One tool, two jobs.
Download Resized Images
Each resized image shows its new dimensions and file size. Download individually or batch-save everything. High-quality resampling keeps images sharp and detailed. Ready for websites, social media, email campaigns — anywhere specific dimensions are required.
Image Resizing Tips
Sizing Images for Social Media
Each platform has its sweet spot. Instagram feed posts: 1080x1080 (square) or 1080x1350 (portrait). Twitter/X in-feed images: 1200x675. Facebook posts: 1200x630. LinkedIn shared links: 1200x627. Pinterest pins: 1000x1500 (2:3 ratio). Matching these exact dimensions means your content never gets awkwardly cropped or stretched. Better visuals, better engagement.
Resizing vs Cropping
They serve different purposes. Resizing scales the whole image up or down — you keep everything, just smaller or bigger. Cropping removes parts of the image to change composition or aspect ratio. Use resizing when you need to fit a layout without losing content. Use cropping when you want to reframe the shot or remove edge elements. For best results, crop first in a dedicated editor, then resize to your target dimensions.
Right Dimensions for Every Use Case
Website hero banners: 1920x1080. E-commerce product thumbnails: 800x800 to 1200x1200. Full product shots: 800x1200. Email newsletter images: 600px max width. YouTube thumbnails: 1280x720. Blog featured images: 1200x630. Using the right dimensions improves visual quality, cuts bandwidth waste, and makes your content look professional everywhere.
よくある質問
リサイズ手順は？
画像をアップロードし、サイズを指定して、リサイズ画像をダウンロードします。
比率が崩れる心配は？
アスペクト比ロックを使用すれば比率は崩れません。
リサイズ後もメタデータは保持されますか？
ツールが画像を再生成するため、基本的なメタデータは削除される場合があります。ほとんどのWeb用途では問題ありません。EXIFデータが必要な場合は、事前に元の画像のコピーを保存してください。
一度に何枚の画像をリサイズできますか？
制限はありません。複数の画像をアップロードし、一度のバッチ処理ですべて同じサイズにリサイズできます。各画像は個別に処理されます。