Key takeaways
- Making an image smaller keeps it sharp; making it larger cannot add real detail.
- Keep the aspect ratio locked, or the picture will look stretched.
- A 4032 × 3024 phone photo resized to 1600 × 1200 keeps under 16% of its pixels and still looks sharp on screen.
- For print, multiply the size in inches by 300 to get the pixels you need.
On this page
Resize in three steps
- Open Resize image and choose a photo, or paste one.
- Enter a width or height in pixels, or a percentage. Leave the aspect ratio locked.
- Download the resized image as JPG, PNG or WebP. Nothing is uploaded.
Keeping the proportions
With the ratio locked, the other side is calculated for you: new height = new width × original height ÷ original width. A 4032 × 3024 photo set to 1600 pixels wide becomes 1600 × 1200. If you need a different shape, such as a square, crop to that ratio first and then resize; changing only one side squashes faces and circles.
Sizes that work
| Use | Suggested width |
|---|---|
| Full-width website image | 1600 to 2000 px |
| Blog or article image | 1200 px |
| Email attachment that still looks good | 1600 px on the long side |
| Thumbnail or product grid | 400 to 600 px |
| Print at 10 × 15 cm (4 × 6 in) | 1181 × 1772 px at 300 ppi |
For print, convert centimetres to inches (÷ 2.54) and multiply by 300: 10 cm is 3.94 inches, or 1,181 pixels.
Why smaller stays sharp and bigger does not
Downsizing averages groups of pixels into fewer pixels, which keeps edges clean. Resizing 4032 × 3024 (12.2 megapixels) to 1600 × 1200 (1.9 megapixels) keeps about 16% of the pixels, and on a laptop or phone screen you will not see a difference. Upscaling has to invent pixels between the real ones, so the result looks soft. If you need a bigger image, go back to the original file rather than enlarging a small copy.
Pixels or kilobytes?
Many forms ask for a file "under 200 KB" or "under 1 MB". Resizing to fewer pixels is the biggest single saving; then Compress images trims the rest with quality settings. Do it in that order: compressing a huge photo hard to hit a size limit looks worse than resizing it sensibly and compressing gently.
Good to know
- DPI is a label. Changing DPI without changing pixels does not affect how an image looks on screen or its file size.
- Portrait or landscape? Setting the width of a portrait photo to 1600 px makes it tall; set the long side instead when you want a consistent size.
- Location data. Phone photos can contain GPS coordinates. Remove photo metadata before sharing publicly.
Fact-checked against the sources above. We test every tool we mention. Editorial policy.
