Image Resizer

English

How to resize an image

This image resizer changes the width and height of a JPG, PNG or WebP photo right in your browser. Pick the method that matches what you were asked for:

1. Add your image by choosing a file, dropping it on the box, or pasting it with Ctrl+V. A sample photo is shown until you do.
2. Choose Pixels to type an exact width and height, Percentage to scale the whole image, or Preset for common sizes such as an Instagram post or a 3 × 4 cm photo.
3. Pick the output format and quality, check the before and after numbers, then download. The file name ends with the new size, for example photo-1080x1080.jpg, so your original stays untouched.

How resizing works

A digital image is a grid of pixels. Resizing draws that grid again at a new width and height and works out the colour of each new pixel from its neighbours. When you lock the aspect ratio, the second side follows the first so nothing gets stretched:

Example: a 4000 × 3000 photo resized to a width of 1200 px becomes 1200 × 900 px. That is 9% of the original pixels, so the file usually ends up many times smaller too.

Percentage mode multiplies both sides by the same number. At 50%, a 1800 × 1200 image becomes 900 × 600, which is a quarter of the pixels. For big reductions the tool shrinks in several halving steps, which keeps fine lines and text crisper than one large jump.

Common sizes

Platforms change their recommended sizes from time to time, so treat these as a good starting point rather than a rule.

Centimetres, dpi and pixels

Forms that ask for a photo in centimetres expect it to be printed or displayed at a certain density, usually 300 dots per inch. One inch is 2.54 cm, so the conversion is:

For a 3 × 4 cm photo: 3 ÷ 2.54 × 300 ≈ 354 px wide and 4 ÷ 2.54 × 300 ≈ 472 px tall. The photo presets also write 300 dpi into JPG and PNG files, so printing software shows the right physical size.

Crop to fill or fit inside?

When a preset has a different shape from your photo, something has to give. Crop to fill covers the whole frame and trims the same amount from both edges, which is what you want for profile pictures and ID photos. Fit inside keeps every part of the picture and adds white bars, which suits screenshots, documents and product shots.

Tips for good results

• Start from the largest original you have. Shrinking stays sharp; enlarging cannot invent detail and may look soft.
• Use JPG for photos, PNG for screenshots, logos and anything with transparency, and WebP for websites.
• Quality between 80% and 92% is a sensible range for JPG and WebP. PNG is lossless, so it has no quality setting.
• If a form also limits the file size, resize first and then use the image compressor to reach the KB limit.
• Resizing removes camera metadata such as location, which is a small privacy bonus.

Limits

Each side can be up to 8000 px, although very large sizes may fail on phones with little memory. Animated GIFs are saved as a single still frame. iPhone HEIC photos usually need converting to JPG first, because most browsers cannot open them directly.

Frequently asked questions