How to use
- Choose one or more JPG or PNG images; the table shows their current DPI.
- Enter the new DPI or click a preset such as 300. The printed size at that DPI is shown.
- Click download. Several files download as a ZIP.
Options explained
- What is changed
- The JFIF, EXIF and XMP resolution fields in JPG, and the pHYs chunk in PNG. Pixels, colours and compressed data are untouched.
- Printed size
- Printed size = pixels ÷ DPI. For example, 2480 pixels at 300 DPI prints 210 mm wide (A4 width).
Pixels needed for common print sizes at 300 DPI
Printed size is pixels divided by DPI, so the pixels you need are the size in inches times the DPI (1 inch is 25.4 mm). Changing the DPI value does not add pixels, so check that your image already has at least this many.
| Print size | Pixels at 300 DPI |
|---|---|
| 4 × 6 in | 1200 × 1800 |
| 5 × 7 in | 1500 × 2100 |
| A6 (105 × 148 mm) | 1240 × 1748 |
| A5 (148 × 210 mm) | 1748 × 2480 |
| A4 (210 × 297 mm) | 2480 × 3508 |
If the image has fewer pixels, setting 300 DPI only makes the printed size smaller: a 1200 px wide photo at 300 DPI prints 4 inches wide, at 72 DPI it would print 16.7 inches wide with the same pixels.
Frequently asked questions
Will 300 DPI make my photo sharper?
No. Sharpness depends on the number of pixels; DPI only sets how many pixels go into each printed inch.
Why aren't the pixels changed?
Most "300 DPI" checks only read the value in the file, and resizing pixels would recompress the image. Use the image resizer to change pixel size.
Are my images uploaded?
No. Everything happens in your browser.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.