How to resize an image
- Drop photos on the box, click it to choose files, paste with Ctrl+V, or click Try a sample photo. The first picture fills Width and Height with its own size.
- Choose a Resize method, or click a social media size, which switches to Fill a box so the picture is cropped, not stretched. With Exact size and the lock on, a new width changes the height to match.
- Pick an Output format and Quality, then click Resize images.
- Click Download on a row, or Download all (ZIP) when you resized several.
How the resize works
Your browser redraws each picture on a canvas at the new size using drawImage with high quality smoothing. For big reductions it halves the picture in steps first, which avoids jagged edges. The methods differ only in how the new size is chosen:
- Exact size uses your width and height as typed, so mismatched proportions stretch the picture.
- Fit in a box uses scale = the smaller of (box width / width) and (box height / height).
- Fill a box uses the larger of those two ratios, then crops the overflow equally from both sides.
- Set width, Set height and Scale by percent keep the proportions and round to whole pixels.
Worked example
Click Try a sample photo: a 1,200 x 800 px JPEG of 200.4 KB, so Width shows 1200 and Height 800. With Exact size and the lock on, type 600 in Width and Height becomes 400. Leave Output format on Same as original and Quality at 90, then click Resize images. The row reads Resized to 600 x 400 px · 28.2 KB (86% smaller file). Next click Instagram square: the method becomes Fill a box, the middle 800 x 800 px of the photo is enlarged to 1,080 x 1,080 px, and the file is 123.6 KB. Sizes vary slightly by browser.
Limits and edge cases
- Output can be up to 16,384 px on a side and 100 megapixels, and phones may stop earlier, showing an error on the row.
- Enlarging cannot add detail, and tick Don't enlarge to leave small pictures alone in a mixed batch.
- GIF, BMP, SVG and AVIF files are saved as PNG when the format is Same as original, and an animated GIF keeps only its first frame.
- Resized files carry no EXIF data, so camera details and GPS location are dropped. Rotation from your phone is applied.
- To shrink the file in KB instead of pixels, use the image compressor. For a free-form cut, use the image cropper; to change format only, the image format converter.
Image resizer FAQ
How do I resize an image without stretching it?
Pick Fit in a box to shrink the whole picture inside your width and height, or Fill a box to cover the size and crop the extra edges. Exact size stretches the picture when its proportions differ.
How do I resize an image to a specific file size in KB or MB?
Resizing changes pixels, not kilobytes, so file size depends on the picture and the quality setting. Lower the width and height, lower Quality, or choose WebP. For an exact limit such as 200 KB, use the Image Compressor's Target file size option.
What size should an Instagram photo be?
Square posts use 1080 by 1080 px, portrait posts 1080 by 1350 px (4:5), and stories 1080 by 1920 px. Click the matching preset to crop the center of your photo to that size without stretching it.
Does resizing an image reduce its quality?
Making a picture smaller keeps it sharp, but saving as JPEG or WebP at a lower quality adds slight compression loss. Making it larger cannot add detail, so enlarged pictures look soft.
Can I resize many images at once?
Yes. Drop several files, choose one method, and click Resize images. Each file gets a Download button, and Download all (ZIP) bundles every result.
Sources: MDN, drawImage; MDN, imageSmoothingQuality; Instagram Help Center. Further reading: image compression for the web guide.