Image Resizer
Resizing by percent multiplies both sides, so 50% turns a 4000 x 3000 photo into 2000 x 1500. With the aspect ratio locked, typing a width works out the height. Photos never leave your device.
How to use
- Drop one or more images onto the box, or press it to choose files. Each file can be up to 50 MB.
- Pick Pixels or Percent. In pixels, type a width or a height and the other side follows when Keep aspect ratio is on. Turn it off to set both sides yourself.
- Choose JPEG, PNG or WebP, then press Resize. Each result appears in the list with its new size and a Download button.
How it works
With Keep aspect ratio on, the side you did not type is worked out from the original shape: new height = new width x original height / original width, rounded to a whole pixel. In Percent mode both sides are multiplied by the percentage.
The image is drawn onto a canvas of the new size inside your browser and saved from there. When the photo shrinks to less than half, it is halved in steps first so thin lines and text stay smoother. Phone photos are turned upright using their EXIF orientation before resizing, so a portrait shot stays a portrait.
Nothing is sent to a server. The page reads each file with your browser, and the result exists only in this tab until you download it.
Common sizes
| Use | Size (px) |
|---|---|
| Instagram post, square | 1080 x 1080 |
| Full HD screen or video thumbnail | 1920 x 1080 |
| Blog or email header | 1200 x 630 |
| Passport-style photo, 35 x 45 mm at 300 dpi | 413 x 531 |
| Profile picture | 400 x 400 |
Pixels or percent
Use pixels when a site or form asks for an exact size, for example a width of 800 px. Use percent when you only want everything smaller by the same amount, such as 50% for half the width and height. A file with half the width and height has about a quarter of the pixels, so the file usually shrinks by a bit more than half.
FAQ
Are my images uploaded?
No. Resizing happens on your device in this browser tab. There is no upload, no account and no copy kept anywhere else. You can even turn off your connection after the page has loaded and it will keep working.
Will resizing lower the quality?
Making an image smaller always throws away detail, and JPEG or WebP output adds a little compression on top. PNG output is lossless. Keep the quality slider at 90 or above if you want the file to look the same on screen.
Why did my phone photo not turn sideways?
Phones store a rotation flag instead of rotating the pixels. This tool applies that flag before resizing, so the result is upright and the flag is not needed any more.
What is the largest size I can make?
Up to 16,384 pixels on a side and 100 million pixels in total. Some phones and older browsers allow less than that. If a size is too large for your device, the list shows an error for that file.
Does it work with GIF or HEIC files?
Any format your browser can open works, but the result is a still image. An animated GIF becomes its first frame. HEIC opens only in browsers that support it, such as Safari.