Image resizer

What it does

Resize image online in your browser: choose a width, a height, a percentage or a box to fit inside, and every file you add is scaled to match while keeping its proportions. The resizer shows the original and new dimensions, the new file size and how much of the original pixel area remains, with a preview of the first image. You can keep the original format or switch to JPG, WebP or PNG, set the quality, and download one file or a zip. Nothing is uploaded.

How to use it

1. Choose one or more images. A 2400 × 1600 sample is loaded to start with.
2. Pick how to resize: by width, by height, to fit a box, by percentage or to an exact size.
3. Enter the target. For a blog image in a 768px column, a width of 1,536px covers sharp screens.
4. Choose the output format and quality.
5. Download the result, or a zip when you resized several files.

How to read the result

Original shows the first image's dimensions and file size. New size shows its dimensions after resizing and the new file size. Pixels is the new area as a share of the original, which is a better guide to the saving than the width alone.

For example, resizing the 2400 × 1600 sample to a width of 800 gives 800 × 533. The width drops to a third, but the pixel count drops to 11% of the original, because both sides shrink. File size tends to fall roughly in line with pixel count, so a 1.2 MB original would land somewhere in the low hundreds of kilobytes at the same quality.

When you add several files, a table lists each one's original and new dimensions and size. While "Never enlarge smaller images" is ticked, files already smaller than the target keep their size, so the two columns match in that row.

Once you have a set of widths, the srcset generator writes the markup that serves the right one to each screen. Right-sized images are one of the first fixes in our technical SEO audits.