Resize Image: by Pixels, Percent or KB

How to resize images

1. Choose images, drop them on the box or paste one with Ctrl+V (⌘V on a Mac). JPG, PNG, WebP, AVIF, GIF, BMP, ICO, TIFF, iPhone HEIC and SVG all work, and you can add many at once.
2. Pick a preset, or type a width or height in pixels. With Lock aspect ratio on, the other side follows, so nothing is squashed; in a batch every image keeps its own shape. Percentage scales both sides.
3. Choose the format, quality and, if needed, a maximum file size. Check the preview, then Download, or Download all (ZIP) for a batch.

Exact sizes: fit, crop, pad or stretch

With the aspect ratio unlocked, choose what happens when a size such as 1080 × 1080 differs from the photo’s shape:

The 3 × 3 position grid picks which part a crop keeps (the top of a portrait, say) or where a padded image sits. Pad with white, black, a colour of your choice or transparency. Never enlarge never scales an image up: one already smaller than the target keeps its size (a crop frame shrinks to fit inside it, and padding surrounds it), which is what you want when shrinking a mixed batch to a maximum width.

Resizing to a file size in KB

Upload forms often cap the size, say at 50 KB. The tool finds the highest JPEG, WebP or AVIF quality that fits by encoding the image several times. If even quality 40 is too big, it also reduces the width and height, keeping the shape, and tells you. Exact-size modes keep their pixel size and go down to quality 5 instead. Lossless formats (PNG, BMP) can only shrink in size. The limit counts 1 KB as 1,000 bytes, so the file also passes checks that count 1,024.

How the resizing works

Your browser decodes each image, turning phone photos upright from their EXIF orientation tag, and draws it at the new size with its best smoothing filter. For big reductions each side is halved step by step until it is at most twice its target, then scaled once more, so fine detail such as hair and text does not break up into jagged edges and moiré. SVG drawings are rendered straight at the new size, so they stay sharp.

Formats

Most browsers cannot write AVIF, so a bundled libavif encoder (3.5 MB, loaded on first use) does it in a few seconds per image. Under “Original format”, HEIC is saved as JPEG and SVG as PNG; a TIFF stays a TIFF (first page, LZW) and a GIF a GIF (first frame, up to 256 colours). Icons are square, so a wide image is centred on a transparent square. The new files carry no metadata such as the camera model or GPS location.