画像サイズを縮小
Reduce an image to a target file size in KB or MB with honest warnings when the target cannot be met.
画像をアップロード
Choose an image, preview each change, and download the edited file. ResizeWizard keeps the workflow simple, fast, and private in your browser.
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画像サイズを縮小
Reduce an image to a target file size in KB or MB with honest warnings when the target cannot be met.
画像を切り抜く
Crop a photo to custom dimensions or common aspect ratios like 1:1, 4:3, 16:9, and 9:16.
Open tool 日本語画像サイズ変更
Resize an image by exact width and height in pixels, with an optional fixed aspect ratio.
Open tool 日本語画像変換
Convert an image to JPG, PNG, WebP, AVIF, TIFF, or GIF when your browser supports the format.
Open tool 日本語画像圧縮
Compress an image automatically while keeping a useful balance of clarity and file size.
Open tool 日本語画像を反転
Flip an image horizontally or vertically without uploading it to a server.
Open tool 日本語画像を回転
Rotate an image left, right, 180 degrees, 270 degrees, or by a custom angle.
Open tool 日本語画像サイズを縮小
Reduce an image to a target file size in KB or MB with honest warnings when the target cannot be met.
Open tool 日本語画像をモザイク化
Pixelate the whole image or a selected rectangular area with adjustable block size.
Open tool 日本語白黒画像
Convert a photo to grayscale or strict black and white.
Open toolFrequently asked questions
画像サイズを縮小 FAQ
Are images uploaded to ResizeWizard?
No. The editor uses browser APIs and canvas processing where possible, so images stay on your device.
Can every browser export AVIF, TIFF, or GIF?
No. ResizeWizard shows those formats where requested, but export depends on browser canvas support. If unsupported, choose JPG, PNG, or WebP.
Can I keep editing after one change?
Yes. After previewing an edit, the preview becomes the current working image, so you can continue with another tool.