Change JPG size
JPG ファイルの幅と高さを正確に指定するか、パーセントで拡大縮小。
新しいサイズをどう指定しますか？
画像を処理中…
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通常は数秒で完了します。
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要点
To resize a JPG, upload it to ezimagetools.com and type the width you need in pixels, or drag the percentage slider. With the aspect-ratio lock on, the height fills itself in so the picture is never stretched. Resizing a JPG re-encodes it, so it pays to resize and compress in one pass rather than saving the same JPG over and over — each save discards a little more detail than the last, and that loss never comes back.. It is free and needs no account.
概要
- 対応形式
- JPG files, up to 20 at a time
- 出力
- The same picture as a JPG at your chosen width and height
- 最大ファイルサイズ
- 1 ファイルあたり 50 MB
- 一度に処理できる数
- 一度に最大 20 件
- 料金
- 無料。処理できる枚数に上限はありません
- アカウント
- 不要です。登録は一切ありません
- ファイルの削除
- 処理から 1 時間以内に自動削除
更新日 2026-08-31
jpg をリサイズ方法
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Add your JPG files
Tap the upload box and choose the JPG pictures you want to resize.
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Pick pixels or percentage
Type the width you need, or drag the slider to scale the whole image.
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Keep the shape
Leave the aspect-ratio lock on and the height fills in for you, so nothing looks stretched.
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Resize and download
Press Resize, then save the new JPG files.
What a JPG is
JPG (also written JPEG) is the format almost every camera and website uses. It saves space by discarding the detail your eye is least likely to notice, which is why it cannot store transparency and why every re-save costs a little quality.
Pixels or percentage?
Use pixels when something else sets the rules — an upload form asking for 1200 pixels wide, or a print shop asking for an exact size. Use percentage when you just want the picture smaller and do not care about the exact number.
よくある質問
Does resizing a JPG reduce its quality?
Resizing a JPG re-encodes it, so it pays to resize and compress in one pass rather than saving the same JPG over and over — each save discards a little more detail than the last, and that loss never comes back.
How do I resize a JPG without stretching it?
Leave the aspect-ratio lock switched on and change only one dimension — the other follows automatically. Stretching happens when the width and the height are changed by different amounts, which the lock makes impossible.
What size should a JPG be for a website?
Match the size it will actually be displayed at, then double it if you are targeting high-density phone screens. A full-width banner is usually 1600 to 2000 pixels wide; anything inside a column rarely needs more than 800. Sending a 4000-pixel image to a 400-pixel slot wastes your visitor's data and nothing else.
Can I enlarge a JPG without it going blurry?
Not really. Enlarging cannot add detail that was never captured, so an upscaled picture always looks softer than the original. Start from the largest copy of the image you have rather than growing a small one.
What is the difference between resizing and compressing a JPG?
Resizing changes how many pixels the picture has. Compressing changes how many bytes those pixels take to store. Resizing to smaller dimensions also cuts the file size, and doing both — resize first, then compress — gives the smallest result that still looks right.
Is it safe to resize JPG files online?
Yes. Your file is processed on our server and deleted automatically within one hour. We never look at it and you do not need an account.
Your images are processed on our server and deleted automatically within one hour. We never look at them and you do not need an account.