Does resizing preserve image quality?

Scaling down generally produces a good-quality result. Scaling up (enlarging beyond the original size) will cause the image to appear blurry, as no new detail can be invented. For JPEG and WebP, the quality slider controls compression after resizing.

What does locking the aspect ratio do?

When the aspect ratio is locked, changing the width automatically updates the height (and vice versa) to keep the same proportions as the original image. Unlock it to enter arbitrary width and height values, which may stretch or squash the image.

Is my image uploaded to a server?

No. Resizing is done entirely in your browser using the HTML5 Canvas API. Your image is never uploaded to any server.

What is the maximum output size?

The tool limits output dimensions to 8000 × 8000 px to avoid browser memory issues. For most use cases this is more than sufficient.

免费工具

Image Resizer

在浏览器中将 JPEG、PNG 和 WebP 图像调整为精确像素尺寸。锁定宽高比或输入自定义宽度和高度。

将图像拖放到此处或点击浏览

支持 JPEG、PNG、WebP

宽高比锁定

锁定宽高比时，改变宽度会自动按比例调整高度（反之亦然），防止图像变形。

如何使用

拖放图像或点击浏览。
输入所需的宽度和高度（或选择预设）。
点击调整 — 输出会显示文件大小对比。
点击下载以保存调整后的图像。

所有调整都在您的浏览器中使用 Canvas API 运行 — 图像不会上传到任何服务器。

常见问题

支持哪些格式？: JPEG、PNG 和 WebP。输出格式始终与输入格式相同。
支持放大吗？: 支持。您可以调整到大于原始尺寸的尺寸，但由于上采样，这会降低图像质量。