Will resizing an image reduce its quality?

Scaling an image down (making it smaller) generally has minimal visible quality loss. Scaling up (making it larger) will cause pixelation since image data is being interpolated. For JPEG and WebP output, you can control the quality level with the quality slider.

What is the 'Longest Side' resize mode?

This mode constrains the longest dimension (width or height, whichever is bigger) to a specified pixel value and scales the other dimension proportionally. It is useful for preparing images for social media, web galleries, or email where a consistent maximum size is needed.

Image Resizer

Resize images by dimensions, percentage or longest side — batch mode, ZIP download, 100% in your browser

Batch support | 100% private

Resize Settings

Applied to all images

Resize Mode

Exact dimensions (W × H) Percentage scale Longest side (px)

Width (px)

Height (px)

Scale

1%100%200%

Longest side (px)

Scales the largest dimension to this value, preserving aspect ratio.

Aspect Ratio

Output Format

Quality

Smaller Best quality

PNG uses lossless compression — no quality setting needed.

Drop images here

or click to browse — PNG, JPEG, WebP, GIF — multiple files supported

Choose Images

Want to reduce file size too?

Try our Bulk Image Compressor — compress multiple images at once with per-image quality control and ZIP download.

What Is an Image Resizer?

An image resizer changes the pixel dimensions of an image. This is useful for preparing images for websites (where a specific pixel size is required), social media posts, email attachments, and print materials.

This tool resizes images entirely in your browser using the HTML5 Canvas API. No image ever leaves your device. You can resize by exact pixel dimensions, by a percentage scale, or by constraining the longest side to a maximum value.

Common Use Cases

Resize product images for e-commerce listings (e.g. 800×800 px)
Scale down large photos before uploading to a website or CMS
Prepare thumbnails or preview images for galleries
Reduce image dimensions before sending by email or messaging
Create social media assets at platform-required dimensions
Batch resize hundreds of images to a consistent size

Frequently Asked Questions

No. All image resizing happens entirely in your browser using the HTML5 Canvas API. Your images never leave your device and no data is sent to any server.

You can upload PNG, JPEG, WebP, and GIF images. You can output resized images as JPEG, PNG, or WebP regardless of the input format.

Scaling an image down has minimal visible quality loss. Scaling up will cause pixelation since new pixel data must be interpolated. For JPEG and WebP output, you can control quality with the quality slider.

Yes. Add multiple images and apply the same settings to all of them. Click "Resize All" to process the batch, then download everything as a ZIP file.

When enabled, changing the width automatically updates the height (and vice versa) to maintain the original proportions, preventing stretched or squashed output.

This mode scales the longest dimension (width or height) to a specified pixel value and scales the other dimension proportionally. Useful for preparing images with a consistent maximum size.