How to use it
Choose how you want to size the picture. In pixels you give a width, a height or both; with only one filled in, the other follows from the picture's proportions, and with both filled in the picture is fitted inside that box unless you pick “exactly this size”. In percent mode both dimensions are scaled equally. For centimetres, millimetres and inches the size is converted to pixels with the DPI you enter (pixels equal inches times DPI), which is how print sizes and on-screen sizes are connected.
Large reductions are done in several halving steps rather than one jump, which keeps fine detail such as text and thin lines noticeably cleaner. Enlarging cannot create detail that was never captured, so enlarged pictures look softer and the tool warns you. You can also limit the final file size in KB: the quality of JPG or WebP output is lowered until the file fits, while the dimensions you asked for stay exactly as set.
All resizing happens in your browser, so photos are never uploaded. EXIF orientation is applied, so phone photos come out the right way up, and hidden metadata is dropped on saving. To shrink file size without changing dimensions use the Image Compressor, to change format use the Image Converter, and for forms that demand exact pixel and KB limits use the Passport Photo Resizer or the Signature Resizer.
Supported formats and limits
| Units | Pixels, percent of the original, centimetres, millimetres or inches (with a DPI you set from 36 to 1200). |
|---|---|
| Proportions | Leave width or height empty to keep proportions, or give both to fit inside that box. “Exactly this size” stretches the picture. |
| Input formats | JPG/JPEG, PNG, WebP, and GIF, BMP or AVIF where your browser opens them. |
| Output | Same format as the original, or JPG, PNG or WebP, with a quality setting and an optional maximum file size in KB. |
| Limits | Up to 50 images at once, each up to 60 MB; output up to 100 megapixels. |
| Privacy | Processed locally in your browser; nothing is uploaded. |
Practical examples
A square profile picture
- Situation
- Set width 1080 and height 1080 and choose “Exactly this size”.
- What to expect
- Every picture comes out 1080 × 1080 pixels. Non-square photos are stretched, so crop first (the passport-photo tool has a crop frame) if you need to keep proportions.
A 4 × 6 inch print
- Situation
- Choose Inches, enter 6 wide by 4 high and keep 300 DPI.
- What to expect
- The target is 1800 × 1200 pixels. A picture with different proportions is fitted inside that box rather than stretched.
Half-size copies of a whole folder
- Situation
- Choose Percent and enter 50, then drop many files.
- What to expect
- Each image becomes half as wide and half as tall, so roughly a quarter of the pixels, and you can download them all as one ZIP.
The numbers behind it
pixels = inches × DPI = (cm ÷ 2.54) × DPI = (mm ÷ 25.4) × DPInew height = new width × (original height ÷ original width)
- DPI (dots per inch) only converts physical sizes into pixels; the saved file does not store it
- Percent scales both dimensions equally
Physical sizes become pixels using your DPI; proportions are kept unless you ask for an exact size.
Honest limits
- Browsers do not write DPI into saved files; DPI is only used to turn cm, mm and inches into pixels.
- Enlarging a picture cannot add detail and makes it look softer.
- Animated images keep only their first frame.