Image Resizer

Resizing is not the same as compressing

Resizing changes the number of pixels in a picture: its width and height. Compression changes how efficiently those pixels are stored. They are related but different, and for large photos resizing is usually the bigger win. A 4,000 by 3,000 pixel photo has 12 million pixels; a 1,200 by 900 version has 1.08 million, about 9 percent as many, and looks identical on most screens.

Resize when you need a picture to fit a specific place: a social media post, a blog header, an online form that asks for exact dimensions, a passport-style photo, or an email signature. Use the Image Compressor when you only want a smaller file.

Three ways to set the size

The resizer offers three routes because people think about size in different ways.

• By pixels. Type a width, a height or both. With one image loaded, changing the width fills in the height that keeps the proportions.
• By percentage. Scale everything to, for example, 50 percent of its original size. This is the quickest way to shrink a batch of pictures by the same amount.
• Social media size. Pick a ready-made size such as an Instagram post (1080 by 1080), a Story or Reel (1080 by 1920), a YouTube thumbnail (1280 by 720) or a header banner.

Fit inside, fill and stretch

When the target shape differs from the picture's shape, you must choose what to do. Keep proportions fits the whole picture inside the target size, so one side may end up smaller than requested. Fill the exact size and crop the edges scales the picture until it covers the target and trims the overflow from the centre, which gives an exact size with no distortion. Stretch forces the exact size and distorts the picture. It is rarely what you want, except for special cases such as a texture.

For a square profile picture from a landscape photo, use "fill and crop"; if the important part is off-centre, crop first with the Image Cropper and then resize.

Quality when making pictures smaller

Shrinking a large picture by a big factor can leave it looking harsh if it is done in one step. The tool reduces large pictures gradually, at most by half per pass, which keeps edges clean. Enlarging is possible, but a picture cannot gain detail it does not have: doubling the size of a small image makes it soft rather than sharp. Start from the largest original you have.

Choose the output format that suits the content: JPG for photographs, PNG for graphics and screenshots, WebP for small files with transparency. The default keeps the original format. See JPG vs PNG vs WebP if you are unsure.

Practical size guide

A few working sizes cover most needs. Blog and article images are usually 1,200 to 1,600 pixels wide. Email images are best at 600 to 800 pixels. Profile pictures are often 400 by 400 pixels. Product photos for shops commonly need 1,000 to 2,000 pixels on the longest side. For high-resolution (retina) screens, use twice the display width, so an image shown 800 pixels wide should be about 1,600 pixels wide.

If you need the picture inside a PDF, resize first and then use JPG to PDF so the document stays small. To build a favicon or a base64 image for a stylesheet, resize to a small size first and then use Image to Base64.

Privacy and limits

Everything runs in your browser; your pictures are not uploaded. You can resize up to 30 at once, with an output side limited to 10,000 pixels and a total of 100 megapixels to protect your device memory. Animated images become single frames. Keep the originals: resizing down discards pixels permanently.