How to resize an image
Drop an image on the tool above. Its current size appears in the width and height boxes. Change either number — with the aspect ratio locked, the other number follows automatically — or pick a percentage, then press “Resize & download”. The resized copy downloads right away. Nothing is uploaded.
Pixels, percent, and aspect ratio
Pixels are exact; percent is quick. Use pixels when a site or form demands a specific size, such as 800 × 600 or 1080 × 1080. Use percent when you just want it smaller — 50% halves each side and quarters the pixel count. The aspect-ratio lock keeps the picture's proportions: turn it off only if you genuinely want to stretch the image, because stretching makes people and objects look wrong.
Resizing down vs. resizing up
Resizing down is safe; resizing up is not. Shrinking a 4000 px photo to 1000 px throws away pixels you do not need, and the result stays sharp. Enlarging a 500 px image to 2000 px invents pixels that were never there — the result looks soft and blurry no matter what tool you use. If you need a bigger image, you need a better original, not a bigger resize.
Common sizes
A few sizes cover most everyday needs. A blog or article image is usually 1200–1600 px wide. A social media post is 1080 × 1080 px square, or 1080 × 1350 px portrait. A profile picture is 400–800 px square. An email signature image should stay under 600 px wide. When a form gives you exact dimensions, use those — and keep the aspect ratio unlocked only if the form's ratio matches your photo's ratio.
File size follows pixel size
Halving the width and height quarters the file size. That is the fastest way to make an image small: a 4000 × 3000 photo at 5 MB becomes roughly 1 MB at 2000 × 1500, before any compression. If you need it smaller still, run the result through the Image Compressor on this site.