Image Tool

在线调整图片大小

免费照片与图片缩放器。以像素更改宽度和高度,保持宽高比,需要时可先裁剪,或通过放大提高照片分辨率。

Free to use No account required Stays on your device Nothing uploaded
Crop preview

Drag to select the crop area

What this free image resizer does

This tool is a photo and picture resizer: it changes the pixel width and height of an image you upload. That controls how large the picture appears at normal display scale. It is different from compression, which mainly targets file size in bytes. Stretching both dimensions without preserving aspect ratio can make subjects look warped.

Use it when a website template, social slot, form, or document asks for exact dimensions. After you resize an image, you can compress the image if the file is still too large to upload.

How to resize an image online

  1. 上传照片或图片. 将 JPEG、PNG、WEBP、HEIC 或其他支持的图片拖放到上传区域,或一次选择多个文件。
  2. 可选先裁剪. 启用裁剪并拖动,在更改尺寸前只保留需要的部分。
  3. 设置新的宽度和高度. 输入像素目标尺寸。开启宽高比时留空一个字段可等比例缩放。
  4. 调整大小并下载. 点击调整图片大小,等待处理,然后下载结果。若文件仍太大无法上传,可之后再压缩。

Photo resizer vs picture resizer — same tool, different jobs

Whether you call it a photo resizer or a picture resizer, the job is the same: set exact pixels so the file fits the place you will use it. Photos from a phone are often thousands of pixels wide; forms and profile slots usually need a few hundred. Downscaling first makes uploads faster and keeps layouts from breaking.

Reduce image size (dimensions)

Enter a smaller width or height to reduce image size on screen. With aspect ratio on, one dimension is enough — the other scales automatically so the photo does not stretch. If you meant fewer kilobytes rather than fewer pixels, finish with the image compressor.

Increase photo resolution online for free

Enable “Allow upscaling,” then enter larger width and height values. That increases the pixel count so a small picture can fill a bigger canvas. Upscaling cannot invent real camera detail — results often look soft if you scale far beyond the original. Use it for modest enlargements, not for recovering lost sharpness.

Crop, then resize

Optional crop lets you keep a face, product, or subject before the dimensions change. Combine crop with Cover fit when a slot needs an exact box and you care which part of the picture fills it.

Common resize sizes

These are starting points, not rules. Always check the site or form that will receive the file — requirements vary.

Use case Typical size Tip
Website hero / banner 1920 × 1080 Keep aspect ratio; compress after if the file is heavy
Social post / feed 1080 × 1080 or 1080 × 1350 Crop first if the platform needs a fixed ratio
Profile / avatar 400 × 400 Square crop, then resize
Form / passport-style Exact px required Enter both width and height; turn aspect ratio off only if the form demands it
Thumbnail 150–300 px wide Downscale aggressively; then compress if needed

Why people resize images online

  • Fixed slots. Templates, CMSs, and social platforms reject or crop files that do not match their pixel box.
  • Faster pages. Serving a 6000-pixel photo in a 800-pixel column wastes bandwidth. Reducing dimensions first cuts weight before compression.
  • Forms and applications. Job portals and school systems often require an exact width and height.
  • Print and slides. Matching the canvas of a document or deck avoids stretch when the picture is dropped in.

Formats, limits, and privacy

Accepted uploads: JPEG, PNG, WEBP, GIF, BMP, TIFF, AVIF, HEIC. Max 200 MB per image.

Limitations: Upscaling cannot invent real detail. Cover fit may crop edges. Savings in file size from resizing alone depend on the original; compress afterwards if you still need fewer kilobytes.

Privacy: Your image is processed locally in your browser and is not uploaded to ImgTask's server. Image files never leave your device. No account is needed and results carry no watermark.

More Tools

Frequently Asked Questions

是的。可免费在线调整图片大小,无需账户、无水印、无需安装软件。适用上传限制(每张 200 MB)。
调整大小改变照片或图片的像素宽度和高度。减小文件大小(字节)是压缩。若调整大小后仍需要更少 KB,请使用压缩图片工具。
可以 — 启用允许放大,然后输入更大的宽度和高度值。放大会增加像素但无法创造真实相机细节。远超原尺寸放大时常见柔和效果。
宽高比是宽度与高度的关系(例如 16:9)。保持宽高比可避免拉伸。关闭后若强制两个尺寸可能使图片变形。
每张图片最大上传 200 MB。约 4000 万像素以上的图片可能在浏览器中失败。
调整大小在浏览器中运行。图片在本地处理,不会上传到 ImgTask 的服务器。
缩小通常效果良好。放大会显得柔和或模糊,因为工具生成了原图中不存在的像素。
可以。调整大小前启用裁剪,选择区域,然后设置目标尺寸。

Blog

Guides and tips from the blog

Short, practical articles to get more out of ImgTask and your image or PDF workflow.

View all articles

Processing…