Image Resizer

Resizing versus compressing

These two get confused constantly, and knowing the difference solves most image problems. Resizing changes the dimensions, so a 4000 by 3000 pixel photo becomes 800 by 600. Compressing keeps the dimensions but stores the image more efficiently, reducing the file size. If a form is rejecting your photo for being too large, you often need both: resize it down to sensible dimensions first, then compress it to hit the exact kilobyte limit.

Hitting a size in kilobytes

Many forms ask for an image under a specific size such as 50KB, 100KB or 200KB. The most reliable way to get there is to resize first, because a smaller image has far fewer pixels to store and therefore compresses to a small file naturally. Once the dimensions are sensible, use the Image Compressor with your target size in KB and it will get you under the limit while keeping the picture as sharp as possible.

Sizes worth knowing

• Passport photo: 413 by 531 pixels covers the standard 35 by 45 mm at 300 DPI.
• Profile picture: 400 by 400 pixels, displayed as a circle on most platforms.
• Instagram square post: 1080 by 1080 pixels.
• LinkedIn banner: 1584 by 396 pixels.
• Full HD wallpaper or slide: 1920 by 1080 pixels.

Do not stretch your image

Keep the aspect ratio locked unless you have a specific reason not to. Unlocking it lets you type any width and height, but the result will look squashed or stretched, which is immediately obvious to anyone looking at a face. When you need an exact shape that does not match your photo, crop to that shape first and then resize.