What is Image Resizer?
Image Resizer is a free, browser-based image resizer, upscaler and format converter. It resizes JPG, PNG and WebP images to any size, crops them for social media and exports them with adjustable quality. Everything is processed locally on your device with the HTML5 Canvas API, so there are no uploads, no sign-up and no watermarks.
Key features
- Resize and upscaleEnlarge or shrink to any width and height, up to 16384 px per side.
- Sharp resultsHigh-quality smoothing and step-down scaling keep images crisp.
- Smart crop presetsYouTube, Instagram, Facebook and X sizes without stretching.
- JPG, PNG and WebPConvert formats and tune quality to balance size and sharpness.
- Aspect ratio lockChange one dimension and the other follows automatically.
- Private by designImages never leave your browser. Works with no account.
How to resize an image online with Image Resizer
- Drag and drop your image into Image Resizer, or click to browse.
- Enter a new width and height, or click a preset such as YouTube Thumbnail.
- Choose a fit mode: Cover (crop), Contain (pad) or Stretch.
- Pick JPG, PNG or WebP and set the quality.
- Check the live preview and click Download image.
Popular image sizes
| Use | Size (px) | Ratio |
|---|---|---|
| YouTube thumbnail | 1280 × 720 | 16:9 |
| Instagram post (square) | 1080 × 1080 | 1:1 |
| Instagram story | 1080 × 1920 | 9:16 |
| Facebook cover | 820 × 312 | about 2.6:1 |
| X (Twitter) header | 1500 × 500 | 3:1 |
| Full HD | 1920 × 1080 | 16:9 |
Frequently asked questions
Is Image Resizer really free?
Yes. Image Resizer is completely free to use. There is no sign-up, no watermark and no limit on how many images you resize.
Are my images uploaded to a server?
No. Image Resizer runs 100% in your browser using the HTML5 Canvas API. Your photos never leave your device, which keeps them private and makes resizing fast.
How do I resize a photo online without losing quality?
Upload your image to Image Resizer, enter the new width and height or pick a preset, keep the aspect ratio locked, choose PNG or a high JPG/WebP quality, and click Download. Image Resizer uses high-quality smoothing and step-down scaling to keep images sharp.
Can Image Resizer upscale an image?
Yes. You can enlarge an image, for example from 1024x1024 to 3000x3000 pixels or more. High-quality smoothing keeps the result as clean as possible, but upscaling cannot add real detail, so very large enlargements will look softer.
How do I resize an image for YouTube, Instagram or Facebook without stretching it?
Click a preset such as YouTube Thumbnail (1280x720), Instagram Square (1080x1080), Instagram Story (1080x1920) or Facebook Cover (820x312). With the default Cover (crop) fit mode, Image Resizer crops from the center so the image is never distorted. Choose Contain (pad) to keep the whole image with padding instead.
Which image formats does Image Resizer support?
You can upload common image formats such as JPG, PNG, WebP, GIF and BMP, and export as JPG, PNG or WebP. JPG and WebP include a quality slider to balance sharpness and file size.