How to change the DPI of an image
- Choose the DPI you need: 300 for print and most application forms, 72 or 96 for screens, 600 for detailed scans and line art.
- Add your images (JPG or PNG, up to 50 at once).
- Download each image, or all of them. The file names get the new DPI added, for example photo-300dpi.jpg.
What DPI really means
A digital image has pixels, not inches. DPI (dots per inch, also called PPI) is a number stored inside the file that tells printers and layout programs how many of those pixels to put in each inch of paper. Changing it changes the print size, not the picture:
| Image | At 72 DPI | At 150 DPI | At 300 DPI |
|---|---|---|---|
| 1200 × 1800 px | 16.7 × 25 in | 8 × 12 in | 4 × 6 in |
| 2400 × 3000 px | 33.3 × 41.7 in | 16 × 20 in | 8 × 10 in |
| 3000 × 4000 px | 41.7 × 55.6 in | 20 × 26.7 in | 10 × 13.3 in |
Why this tool doesn’t lose quality
- No re-compression: most online converters decode the image and save it again as a new JPG, which loses a little quality each time. This tool only edits the resolution fields in the file header, so the image data is copied byte for byte.
- Both places JPEG stores DPI: the JFIF header and the EXIF data (used by phones and cameras, and read first by Photoshop and Windows). Both are updated, so every program shows the same value. Photos without a JFIF header get one added.
- PNG: the pHYs chunk is set (PNG stores pixels per metre, so 300 DPI shows as 299.99 in some programs, which is normal).
When you need more than a DPI change
If a print shop says your photo is “too low resolution”, it doesn’t have enough pixels for the size you want. Changing the DPI won’t fix that. Use the photo print size calculator to see the largest sharp print your photo allows.
Frequently asked questions
Does changing the DPI reduce quality?
No. This tool changes only the resolution setting stored in the file header. The pixels are not decoded or re-compressed, so the picture is bit-for-bit the same.
Why does a form or print shop ask for 300 DPI?
DPI tells printers how big to print the image: at 300 DPI a 1800 × 1200 px photo prints at 6 × 4 in. Many forms and print services check this setting and reject 72 or 96 DPI files even when the pixels are fine.
Will 300 DPI make a blurry photo sharp?
No. DPI doesn’t add detail; it only sets the print size. For a sharp print you need enough pixels: about 300 for every inch of print. The tool shows the size each image will print at.
Which formats are supported?
JPG/JPEG and PNG are edited losslessly, including camera and phone photos with EXIF data (both places where JPEG stores DPI are updated). Other formats such as WebP are saved as PNG first.
Are my images uploaded?
No. The files are edited in your browser, so they never leave your device.
Last updated 2026-10-24.