Resize an image.
This free image resize tool scales JPG and PNG images by percentage or exact pixel size for faster uploads and smaller attachments — batch process as many as you like, without a single file leaving your device. Making an image larger can’t add detail, so enlarged pictures look soft.
More image tools
See all tools
Image ConverterAny image to JPG, PNG or WebP, with resizing. Mix formats in one go.
Image to PDFCombine JPGs or PNGs into one PDF.
HEIC to JPGOpen iPhone photos anywhere.
Compress ImageShrink JPG or PNG file size.
Meme GeneratorAdd top and bottom captions to an image.
GIF MakerTurn a set of images into an animated GIF.
Image CropperCrop a JPG or PNG freely or to a locked aspect ratio.
Passport Photo CheckerCheck a photo against the UK online passport photo rules.
AI Image CheckerSee if a picture says it was made or edited with AI.Image resize: quick facts
Resize JPG and PNG images by percentage or exact pixels.
Updated
- Price
- Free. No sign-up, no watermark.
- Modes
- 25%, 50% or 75%, or exact width and height, with proportions kept by default.
- Batch
- Resize as many as you like; several come back as a .zip.
- Output
- Same format as the original, saved as a new copy ending -resized.
- Privacy
- Your images stay in your browser and are never uploaded.
How to resize images by percentage or pixels
Scale every image to 25%, 50% or 75%, or fit it to a width and height you type in. Each file keeps its format and comes back as a copy with -resized added to its name.
- 01
Add your images
Drop in one or more JPG or PNG files.
- 02
Choose percentage or exact size
Scale proportionally, or fit within (or force) a target pixel size.
- 03
Save your images
One downloads directly; several come back as a .zip.
Tips for resizing without stretching or blurring
Resizing is simple until a photo comes out squashed or soft. These settings help you avoid both.
- Type one side and let the other followIn Exact size, fill in just the width, or just the height, and the other side is worked out from each image’s own proportions. It’s the quickest way to meet a rule like “no wider than 1,200 pixels”.
- Use a box for mixed batchesEnter both a width and a height and leave “Fit within this size” ticked. Portrait and landscape images each shrink to fit inside that box without stretching, so a 1,200 × 1,200 box caps every image at 1,200 pixels on its longest side.
- Crop first to change the shapeResizing keeps an image’s shape. If you need a square or 16:9 picture from a photo that isn’t that shape, cut it with Image Cropper first, then come back and resize it to the exact pixels you need.
- Compress afterwards if the file is still bigResizing saves JPGs at a high quality setting, so a small, heavily compressed JPG can even come out larger in kilobytes. If you’re up against a file-size limit, put the resized image through Compress Image as a final step.
Like every Altto tool, this runs on your device — nothing you add is uploaded. How Altto works
is the usual target for a sharp photo print. A 10 × 15 cm print at 300 dpi needs about 1,181 × 1,772 pixels, so don’t go smaller than that if you plan to print.
Frequently asked questions
How the settings behave, and how big to go. Our guide on how to resize an image also covers Windows, Mac and phones. Getting a photo ready for a UK passport application? Check it with our passport photo checker before you upload.