AscendLab

Image tools

图片尺寸调整

New free tool

Private Image Resizer for JPG, PNG, and WEBP

Resize images by exact pixels or percentage scale, keep the aspect ratio when needed, and export JPG, PNG, or WEBP files without uploading the source image.

Quick answer

An image resizer changes the pixel width and height of a JPG, PNG, or WEBP file.

This tool runs in your browser, so it is best for fast private resizing before uploads, emails, posts, or docs.

Best inputs for resizing

Use source images with enough pixels

Downscaling usually looks clean. Upscaling can make soft images look softer because it invents extra pixels.

Pick the destination size first

Use exact width and height for product cards, banners, thumbnails, social images, or document inserts.

Free ToolBrowser-only processing
Image Resize Studio
Upload an image, enter final dimensions or a percentage scale, then export the resized file locally.

Drop image here or click to upload

Supported format: JPG / PNG / WEBP, max 15MB

No image uploaded

Resize Controls
Set pixels, keep the aspect ratio when needed, and choose the export format.

Keep width and height proportional while editing either field.

100%
1200 x 630px
86%

Private by default

The image is resized in your browser with canvas. It is not uploaded to AscendLab or a third-party API.

Best-fit workflows
Image resizing is most useful when a platform or layout expects specific dimensions.

Product and marketplace images

Create consistent 800 x 800, 1200 x 1200, or other fixed-size exports before uploading listings.

Social and Open Graph images

Resize visual assets to common preview dimensions before checking or compressing them.

Docs, slides, and email

Reduce very large screenshots before placing them in documents, decks, or emails.

Resizing tips that help
Small choices can keep resized images sharp and predictable.
Keep the aspect ratio on unless the destination specifically requires a stretched image.
Use WEBP for small web files, JPG for broad compatibility, and PNG for crisp graphics with transparency.
Resize before compression when you need both final dimensions and a smaller file size.
Example
Upload a 4032 x 3024 phone photo, set width to 1200 with aspect ratio locked, export WEBP at 86 percent quality, then use the smaller file in a blog post.
Assumption
The browser can decode the source image and create a canvas for the chosen output dimensions. Very large files may need a desktop browser.
Limitation
Canvas export may remove metadata such as EXIF camera data, and upscaling cannot restore detail that was not in the original image.

Suggested workflow

Resize and prepare a clean image

Use this path when an image needs final framing, dimensions, and file-size cleanup.

Step 1
Crop the frame
Trim unwanted edges and choose the visual composition first.
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Step 2
Resize dimensions
Set the final pixel width, height, or scale for the destination slot.
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Step 3
Compress the export
Reduce file size after the final dimensions are correct.
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Related tools

Keep preparing the image

Image Crop Tool
Crop images to the frame you need before resizing.
Open tool
Image Compressor
Compress resized exports for lighter uploads and faster pages.
Open tool
Aspect Ratio Calculator
Calculate proportional dimensions before choosing final pixels.
Open tool
OG Image Size Checker
Check whether a social image export fits common Open Graph sizes.
Open tool
Frequently asked questions

Does this image resizer upload my file?

No. The image is loaded and resized in your browser. The current tool does not send your image to a backend for processing.

Can I resize JPG, PNG, and WEBP images?

Yes. The tool accepts JPG, PNG, and WEBP images and can export the resized result as JPG, PNG, or WEBP.

Can I keep the original aspect ratio?

Yes. Keep aspect ratio enabled to update height when width changes, or width when height changes.

Can I resize an image by percentage?

Yes. Use the scale control to resize the image from 1 percent to 400 percent of the original dimensions.

Will resizing reduce file size?

Usually, smaller pixel dimensions reduce file size. Export format and quality also affect the final size, especially for JPG and WEBP.