How to use
- Drop your images onto the box above, or click to choose files.
- Choose whether to resize by Width, Height or Percent, then enter the target.
- Optionally change the output format and quality.
- Each row shows the original and new dimensions. Download individually or all at once.
The other dimension is always calculated to preserve the aspect ratio, so images never come out stretched.
Choosing a target size
The most common mistake is uploading images at their original camera resolution. A modern phone produces images around 4000 pixels wide. Displayed in an 800-pixel column, roughly 96% of those pixels are downloaded, decoded, and then thrown away by the browser — paid for in bandwidth and battery by every visitor.
The practical rule is to match the largest space the image will occupy, then double it for high-density displays. A photograph shown in a 600-pixel-wide article column wants a file around 1200 pixels wide. A full-width hero on a desktop layout might want 2400. Going beyond that buys nothing visible.
Shrinking is cheap, enlarging is not
Reducing an image is a genuinely lossless-feeling operation: there is more information in the source than the destination needs, so the result is sharp and the file gets dramatically smaller.
Enlarging is the opposite. Interpolation can only estimate the value of new pixels from their neighbours — it cannot add detail that was never recorded. Up to about 150% the softening is subtle. Past 200% it is obvious, and no amount of sharpening afterwards genuinely restores what is missing; it only increases local contrast around the blur. When you need a larger image, the right answer is almost always to find a larger original.