Image Resizer — what it does
Resizes images to exact pixel dimensions or a percentage, right in the browser — with aspect ratio locked by default so nothing stretches. Built for the unglamorous specs that block uploads: 400×400 profile photos, 1200 px blog widths, passport-photo pixel rules.
How to use Image Resizer
- Drop the image — it opens locally, nothing uploads.
- Enter target width or height; the other dimension follows automatically when the ratio is locked.
- Or pick percentage mode for quick 50% down-scales.
- Choose the output format (keep original, JPG, PNG or WebP).
- Download the resized file; originals stay untouched on your disk.
Worked example: the 400×400 avatar rule
A 3024×4032 phone photo needs a square crop for a 400×400 avatar. Lock the ratio, set width 400 (height follows to 533), then use the crop-friendly square mode for the final 400×400. Uploading the original would have sent a 3 MB file where 30 KB does the job — resizer first, compressor second if you need both.
At a glance
| Modes | Exact pixels (aspect-locked), percentage, square/crop-friendly output |
|---|---|
| Formats | Keeps original or converts to JPG/PNG/WebP |
| Batch | Multiple images, same rule applied to each |
| Privacy | Canvas processing on-device — originals never leave the computer |
| Limits | Downscaling is high quality; extreme upscaling invents nothing (for enlargement see the upscaler) |
Frequently asked questions
- What is Image Resizer?
- Resize images to exact dimensions with a canvas-based preview.
- Is Image Resizer free to use?
- Yes — Image Resizer is free to use, with no sign-up, no install and no account.
- Does Image Resizer upload or store my data?
- No — Image Resizer runs entirely in your browser, so your text, files and results never leave your device.
- Do I need to install anything to use Image Resizer?
- No — it works in any modern browser (Chrome, Edge, Firefox, Safari) with no downloads, accounts or plugins.
- Does resizing change quality?
- Downscaling usually IMPROVES perceived quality per kilobyte — fewer pixels, sharper detail at display size. Upscaling cannot create real detail; large enlargements go soft.
- Resize or compress first?
- Resize first. Deleting pixels you don't need makes any later compression cheaper — the two tools are sequential on purpose.
- Why does my 400×400 come out 400×533?
- Because aspect ratio is locked — the photo wasn't square. Unlock the ratio only when distortion is truly acceptable, which is almost never.