Image Resizer

Resizing scales the entire image to new dimensions — content is preserved but scaled. Cropping cuts a rectangular portion out of the image and discards the rest. Use resize when you want the whole image at a different size; use crop when you want only part of it. They're often used together — crop to the desired aspect ratio, then resize to specific dimensions.

Resize first, then compress. A 4000×3000 image displayed at 800×600 wastes both bandwidth (you sent 25× more pixels than needed) and quality (browser downscaling adds blur). Always resize to actual display dimensions first, then apply compression.

Yes, dramatically — file size scales roughly with pixel count. Halving both width and height reduces file size by ~75%. A 4MB photo resized from 4000×3000 to 2000×1500 will be roughly 1MB at the same quality settings.

The browser's canvas resizing uses bicubic interpolation — it's fast and smooth but doesn't add real detail. For cleaner upscales (especially for 2× or larger), AI-based upscalers like our Image Upscaler tool produce much sharper results. Bicubic is fine for 1.1× to 1.5× scaling; beyond that the quality loss becomes obvious.

Downscaling generally preserves quality well — you're discarding detail rather than fabricating it. Upscaling above the original resolution always loses sharpness because there's no information to fill in. Repeated downscale/upscale cycles compound losses; always go straight from the original at the largest size you have.

Match the actual display size, with a 2× multiplier for high-DPI (Retina) displays. A hero image displayed at 1200px wide should be 2400px wide for sharp rendering on retina. Common targets: thumbnails 200–400px, profile pictures 256–512px, content images 1200–1600px wide, hero/banner 2000–2400px.