Resize Image
Change a picture’s size in pixels — by width, height, longest side, exact box or percentage — keeping its shape. One or many at once.
Drop pictures here, or choose them. JPEG, PNG, WebP, GIF and BMP; HEIC and AVIF where your browser opens them.
Resize
Made in this browser. Your pictures are not uploaded, and nothing is kept after you close the tab.
Runs in your browser — nothing you enter leaves this device.
About this tool
What it does
Resize Image changes how many pixels a picture has — for a website that wants 1,200 pixels across, a form that asks for 600 × 800, a social post, or a photo too large to email. Choose how: by the longest side, by width, by height, by an exact width and height, or by a percentage. The picture keeps its shape unless you choose an exact size and untick Keep its shape, which stretches it. Before you make it, the new size in pixels is shown. Large reductions are drawn in halving steps, which keeps fine detail and text sharp instead of jagged. Add several pictures and resize them all with the same rule, downloaded as one ZIP; each file is opened again and checked to be the size asked for.
How to use it
- Choose pictures, or drop them on the page.
- In Size by, pick Longest side, Width, Height, Width and height, or Percentage, and type the number.
- Check the line that shows the old and the new size in pixels.
- Choose the format to save in, or keep the same one.
- Press Make it, or Make all for every picture, then download.
Limits and your data
- Making a picture larger than it was adds pixels but not detail: it will look softer, not sharper.
- The largest picture a browser can draw is about 16 megapixels on phones and 16,384 pixels on a side; sizes beyond that are brought within it.
- A resized picture is saved afresh, so the camera, time and location details of the original are not carried over.
- To change the shape — square from a rectangle — without stretching, crop first in Crop Image.
- Your pictures are resized in this browser tab, in a background worker, and never uploaded to ToolsDev or anyone else. Nothing is kept after you close the tab; the page downloads only its own code.
Questions
What size should a photo be for the web?
For a picture across a page, 1,200 to 1,600 pixels on the longest side is plenty; for a thumbnail, 300 to 600. Larger only adds to the download.
Does resizing reduce the file size?
Yes, usually a lot: half the width and height is a quarter of the pixels. To reach a particular number of kilobytes, use Compress Image after resizing.
Can I resize to exactly 600 × 800 without distortion?
Only if the picture already has that shape (3:4). Otherwise crop it to 3:4 first in Crop Image, then resize; or tick Keep its shape, which fits it inside 600 × 800 without stretching.
Can I resize a hundred photos at once?
Yes. Add them all, set the rule once and press Make all. They are done one after another on your device, so a large batch takes a while on a phone.