Image Resizer

How to use Image Resizer

1. Drop an image onto the panel or click to browse.
2. Enter a target width or height, pick a percentage, or choose a social platform preset.
3. Download the resized image. The original file on your device is untouched.

What size should social media images be in 2026?

Every platform re-compresses what you upload, so supplying the exact native dimension avoids a second lossy resize on their servers.

How does downscaling affect quality?

Downscaling in one step from 4000px to 400px throws away 99% of the pixels, and a naive nearest-neighbour sample will alias badly — fine textures turn into moiré, and thin lines vanish or double.

This tool sets imageSmoothingQuality: "high", which selects the browser’s best resampling filter, and applies stepped downscaling for reductions greater than 2× — halving repeatedly until within 2× of the target, then doing the final step. That is the same technique high-end image libraries use and it preserves noticeably more detail than a single large jump.

Upscaling is a different matter. Enlarging beyond the original resolution invents pixels that were never captured. The result looks soft, and no amount of sharpening restores information that is not in the file. Where you need genuine upscaling, an AI super-resolution model is the only real answer.

Should I resize or compress?

Resize first, then compress. File size scales roughly with pixel count, so halving both dimensions cuts pixels by 75% before any compression is applied.

The most common web performance mistake is serving a 4000×3000 camera image in a slot that displays it at 800×600. The browser downloads all 12 megapixels, decodes them into about 48 MB of memory, and then throws away 96% of them at paint time. Resizing to 1600×1200 — 2× the display size, for high-DPI screens — before compressing typically turns a 4 MB request into 180 KB.

What does aspect ratio lock actually do?

With the lock on, typing a width recalculates the height so the proportions are preserved and nothing is distorted. Turn it off and you can set both independently, which stretches the image.

When you need a specific aspect ratio that does not match the source — a 16:9 thumbnail from a 4:3 photo — stretching is the wrong answer. Use the Image Cropper to cut the frame to the right shape first, then resize. Cropping loses content at the edges; stretching makes every face in the picture look wrong.

Frequently asked questions