Image Resize
Resize an image to specific dimensions
When to resize an image?
Phone cameras shoot at 12–48 megapixels — way larger than most uses need. Resizing before upload shrinks file sizes proportionally to the area reduction (a 50% smaller side = 25% the area = ~25% the file size). Web pages render at 1–2x the displayed size on retina; anything larger is wasted bandwidth.
Always preserve aspect ratio unless you specifically want to stretch or squash the image. The tool defaults to locked aspect ratio: change one dimension and the other follows. Algorithm-wise, the browser uses bicubic interpolation by default — sharp enough for downscaling, soft when upscaling beyond original (no algorithm can invent detail that wasn't there).
Common use cases
- Resize a 4032×3024 phone photo to 1920×1440 for a website hero image — shrinks the file from ~5MB to ~600KB.
- Make a square thumbnail from a portrait — set both dimensions to 400px, accept the centred crop.
- Resize a screenshot to fit a forum post that has a 1MB image limit.
- Generate icon sizes — 256, 128, 64, 32 — by repeating with locked aspect ratio.
Frequently asked questions
Will resizing reduce quality?
Downscaling (making smaller) preserves quality if the algorithm is good — bicubic, used by browsers, is fine. Upscaling beyond original always softens; no tool can recover detail that's not in the source.
Should I resize before or after compression?
Resize first, then compress. Compressing a large image and then resizing wastes the compression effort.
How do I keep the aspect ratio?
Lock the aspect ratio toggle (default on). Change one dimension and the tool calculates the other to match the original ratio.
What's the maximum size?
Limited by browser canvas size — typically up to ~16384×16384 pixels. For larger, use desktop tools like ImageMagick.
Is my image uploaded?
No. Resizing uses the browser's Canvas API; nothing leaves your device.