Image Resizer

Resizing changes how many pixels an image contains. That matters more than compression for most oversized photos: a 4000 × 3000 camera image shown in a 800-pixel-wide column carries twenty-five times more data than the screen can use. Scaling it down first, then compressing, usually beats compressing alone by a wide margin.

This resizer offers three ways to specify the result. Exact dimensions when a platform demands a specific size, percentage scaling when you just want something roughly half as big, and fit-to-box when you need an image to sit inside a maximum width and height without distorting it.

Downscaling is done in successive halving steps rather than one jump. Browsers resample in a single pass by default, which throws away pixels and leaves fine detail looking ragged; stepping down gradually averages neighbouring pixels and keeps text and thin lines much cleaner.

You can scale an image up here, but be realistic about the result. Enlargement invents pixels by interpolating between the ones that exist — it cannot recover detail that was never captured. A 200-pixel image blown up to 2000 pixels will look soft and plasticky no matter which tool does the work.

If you need a larger version, always go back to the original file before it was downsized. Only when no original exists is upscaling worth trying, and then keep the increase modest — up to about 200% usually still looks acceptable.