Resize Image

Resizing an image means changing its dimensions in pixels. Because fewer pixels mean less data, it is the most effective way to reduce the file size of a photo. This tool lets you enter a new width or height from 1 to 16,384 pixels. With the aspect ratio locked, the other value updates automatically so the picture is not stretched. For example, a 4000 by 3000 pixel photo resized to a width of 1000 pixels becomes 1000 by 750 pixels, which is one sixteenth of the original pixel count. You can then save the result as JPG, PNG or WebP and set the quality for JPG and WebP. Shrinking removes detail, and enlarging cannot add it back, so scaled-up images look soft. The resizing is done by your browser on your own device, so the image is not uploaded or stored.

Large photos slow down emails, uploads and web pages. Reducing the pixel dimensions is the most effective way to cut the file size, because fewer pixels mean less data.

Only shrink when you need to. Enlarging an image cannot add detail, so it will look soft.

Say a phone photo measures 4000 by 3000 pixels and you want it 1200 pixels wide for a blog post. Choose the file, keep the aspect ratio locked and type 1200 in the width field. The tool calculates the height as 1200 multiplied by 3000 and divided by 4000, which is 900, so the new size is 1200 by 900 pixels. The ratio stays 4 to 3, so nothing is stretched.

The pixel count drops from 12,000,000 (4000 times 3000) to 1,080,000 (1200 times 900), which is 9 percent of the original. The file shrinks by a similar order of magnitude, though the exact result depends on the picture and the format you pick. The result panel shows the new dimensions and file size next to the original, and tells you how much smaller or larger the file is.

You can also start from the height. Typing 1080 in the height field of the same photo gives a width of 1440, because 1080 times 4000 divided by 3000 is 1440. Values are rounded to whole pixels. If you untick the lock, you can enter both numbers freely, but a ratio that differs from the original will stretch or squash the picture.

The three terms are often mixed up. **Resizing** changes the width and height of the whole picture, so everything stays in the frame, just at a different scale. This tool resizes only. **Cropping** cuts away the edges to change the framing or the shape, and the remaining pixels keep their original size. **Compressing** keeps the dimensions and lowers the file size by storing the data more economically, which usually costs some fine detail.

For a smaller file, resizing usually has the biggest effect, because the file has far fewer pixels to store. If the dimensions are already right and you only want a lighter file, try [compress image](compress-image) instead. You can combine both: resize first to the size you really need, then compress.

Making an image larger does not recover detail that was never captured. The browser has to invent the extra pixels by blending neighbouring ones, so an enlarged photo looks soft or blurry. If you must scale up, keep the factor small, and wherever possible start from the original, larger file instead of a copy that was already shrunk.

The output format matters too. JPG and WebP let you set the quality, and lower values give smaller files with more visible loss. PNG has no quality setting and keeps every pixel exactly. JPG cannot store transparency, so transparent areas are filled with white when you save as JPG. Choose PNG or WebP if you need to keep a transparent background.