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画像ツール カテゴリ

画像リサイズツール

ブラウザ内で画像サイズを変更。幅と高さを設定し、縦横比を固定してダウンロードできます。

ツールを読み込み中…

このツールはブラウザ内で動作します。入力内容、ファイル、生成した値はこの端末に残ります。お気に入りと最近使ったツールを利用する場合も、ローカルストレージに保存されるのはツール名だけで、パスワード、文書、QR コードの内容は保存されません。 詳しくはプライバシーポリシーをご覧ください。

このツールの詳しい解説（使い方、例、よくある質問）は、現在英語のみでご用意しています。

What this tool does

Set a new width and height for a JPG, PNG, or WebP, with the proportions locked unless you turn that lock off. Use it when a photo must fit a pixel size, such as 1200 by 630. If you need to cut out a region instead of scaling the whole picture, use the Image Cropper.

How to use

  1. Upload a JPG, PNG or WebP image.
  2. Check the original width and height.
  3. Enter a new width or height. Leave aspect ratio locked to keep proportions.
  4. Press Resize, review the new size, then download or reset.

Examples

  • Halve a 2000×1000 image

    With aspect ratio locked, width 1000 sets height to 500.

  • Unlocked dimensions

    Turning the lock off lets you set width and height independently, which can stretch the image.

How it works

Resizing draws the image onto a canvas at the size you choose. Width and height must be whole numbers from 1 to 8192 pixels. Locked aspect ratio updates the other side from the original proportions. Output JPEG, PNG or WebP uses the same in-browser encoder as the compressor.

Limitations

JPG, PNG, and WebP are the formats that open. Width and height have to be whole pixels from 1 through 8192. Turning the aspect lock off can stretch the picture. Cropping, rotation, and background removal are not available.

See the disclaimer for what these tools do not cover.

FAQ

Is the Image Resizer free?
Yes. Changing an image’s width and height in this browser is free, with no account.
Does this upload my photo?
No. The new width and height are drawn in this tab. The photo is not posted to a server.
Why is there a size limit?
Very large dimensions can freeze a tab. This tool stops at 8192 pixels on each side.
How do I resize an image without stretching it?
Keep the aspect ratio locked and change only the width or the height. The other side is calculated so the picture keeps its proportions.
Does resizing an image reduce its file size?
Usually, yes. Fewer pixels means less data to store. For the smallest file, resize first and then compress the result.
Does it work on mobile?
Yes. You can open this page on a phone or tablet. File pickers and downloads use the browser on your device. Large files may be slower on a small phone than on a desktop.

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