Image Resizer

How to Use

Select an image and the tool reads its original dimensions. Type a new width and, with 'Lock aspect ratio' enabled, the height updates automatically to keep the proportions correct. Uncheck the lock if you need exact non-proportional dimensions. Click Resize, then download the result as a PNG.

Why This Tool Is Useful

Uploading a 4000-pixel-wide photo to a website that displays it at 800 pixels wastes bandwidth and slows the page. Many platforms also require specific dimensions — profile pictures, thumbnails, banners, marketplace listings. Resizing first gives you exactly the size you need, and doing it locally keeps private images off third-party servers.

Resizing and Aspect Ratio

Aspect ratio is the relationship between an image's width and height. Changing one without the other stretches or squashes the picture. With 'Lock aspect ratio' on, entering a width automatically calculates the matching height (and vice versa), so the image always stays correctly proportioned.

Turn the lock off only when you deliberately need exact dimensions and don't mind distortion — or when the image will be cropped anyway.

Downscaling vs Upscaling

Making an image smaller (downscaling) is lossless in appearance — you're discarding pixels you didn't need, and the result looks clean and sharp.

Making it larger (upscaling) invents pixels that were never captured, so the result gets soft or blocky. For best quality, always start from the largest original you have rather than enlarging a small file.

Common Image Sizes

Different platforms expect different dimensions. The table below lists a few common targets to save you looking them up.

Tips for Best Results

A few pointers:

• Resize before compressing — the two together give the smallest file.
• Keep the aspect ratio locked unless you have a specific reason not to.
• Never upscale if you can re-export from the original instead.
• For web images, match the size the image actually displays at.

Common Image Dimensions