How to resize an image
- Choose an image from your device or drag it onto the box.
- Set the new size. Type a width or height in pixels — with Keep proportions ticked, the other side is calculated for you — or switch to Percentage and drag the slider. The quick-width buttons cover common sizes.
- Choose a format and, for JPEG or WebP, a quality level.
- Check the preview and download. The original file on your device is left untouched.
What this tool does
The Image Resizer changes the pixel dimensions of an image — how many pixels wide and tall it is. That is different from compression, which keeps the dimensions and reduces the file size by encoding the pixels more efficiently. You usually need resizing when a website, marketplace or form asks for a specific size (for example "at least 1080 pixels wide" or "400 × 400"), when a photo from a modern camera is far larger than it will ever be displayed, or when you want a smaller thumbnail.
Like all our image tools, the resizer works entirely in your browser. Your picture is not uploaded.
How resizing works
Aspect ratio
The aspect ratio is the relationship between width and height. A 4000 × 3000 photo has a 4:3 ratio. If you resize it to 1200 pixels wide with proportions kept, the height becomes 1200 × 3000 ÷ 4000 = 900 pixels. Untick Keep proportions only when you deliberately want to stretch or squash the image — doing so distorts faces and circles.
new height = new width × original height ÷ original width
Downscaling quality
When an image is made much smaller in one jump, fine details can shimmer or look jagged. The resizer shrinks large reductions in several halving steps with high-quality smoothing, which keeps edges and text noticeably cleaner.
Enlarging images
You can scale up to 200%, but enlarging cannot add detail that was never captured — the browser can only estimate the new pixels, so enlarged images look softer. When you need a large image, start from the largest original you have.
Common sizes
| Use | Typical size | Notes |
|---|---|---|
| Full-width website image | 1600–1920 px wide | Compress afterwards to keep the file small |
| Blog content image | 800–1200 px wide | Matches most article column widths on high-density screens |
| Social sharing (link preview) | 1200 × 630 px | A widely used size for link preview images |
| Square profile or post image | 1080 × 1080 px | Crop to square first if your photo is not square |
| Email image | 600–800 px wide | Many email layouts are about 600 px wide |
Tips
- Resize first, then compress. After resizing, run the image through the Image Compressor for the smallest file at acceptable quality.
- Do the maths when a site gives a ratio. If a site wants a 16:9 image 1280 wide, the height is 1280 × 9 ÷ 16 = 720 pixels. The Percentage Calculator can help with scaling percentages.
- Keep PNG for graphics with transparency; converting to JPEG fills transparent areas with white.
- Print sizes depend on resolution: a 3000-pixel-wide image printed at 300 pixels per inch is 10 inches wide. Use the Unit Converter to switch inches to centimetres.
Read How to Compress Images Without Losing Too Much Quality for a full workflow that combines resizing and compression.
Frequently asked questions
Does resizing reduce image quality?
Making an image smaller removes pixels, but with high-quality smoothing the result usually looks sharp at its new size. Enlarging an image makes it softer because detail cannot be invented.
How do I resize without stretching the image?
Keep Keep proportions ticked and change only the width or the height. The other dimension is calculated to preserve the aspect ratio.
What is the difference between resizing and compressing?
Resizing changes the number of pixels (dimensions). Compressing keeps the dimensions but encodes the pixels more efficiently. Doing both gives the smallest files.
Are my images private?
Yes. The resizing happens in your browser; the image is never uploaded to our server or any other service.
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