Image Resizer

Picking the right dimensions

For the web, size an image for the space it fills times the screen's pixel density. An image shown 800 pixels wide on a high-density phone or laptop screen needs about 1600 pixels to look crisp; more than that only adds weight.

Common targets: 1200 × 630 for link previews on social platforms, 3840 × 2160 for a YouTube video thumbnail, 1080 × 1080 for a square Instagram post and 1080 × 1350 for a portrait one.

Changing the shape

Resizing with the ratio locked keeps the picture's proportions. To go from a 4:3 photo to a 16:9 banner, crop to the new shape first and then resize; unlocking the ratio instead stretches faces and circles.

Enlarging adds pixels but not detail, so an image doubled in size looks soft. Start from the largest original you have.

Pixels and print size

A printer needs pixels per inch rather than a pixel count alone: divide the pixel width by 300 to get the width in inches it prints sharply at. The print size calculator does this for any size, and the DPI checker reads the density a file declares.

How to use it

1. Choose a JPG, PNG, or WebP image.
2. Enter a width or height and keep the ratio locked if desired.
3. Choose an output format, resize, and download.

Privacy & limitations

Processing is local to your browser. Very large images are capped at 80 megapixels to avoid exhausting device memory.