How it works
Upload
Drop a PNG or JPG into the box above — it is read locally on your device, nothing is uploaded anywhere.
Check
The tool instantly reads the embedded DPI (or tells you none is set) and shows the print size it produces.
Set
Pick 72, 150, 300 or 600 DPI — or type any value from 1 to 2400 — and download your re-tagged file.
DPI sets print size — not image quality
Here is the one thing most people get wrong: DPI does not make your image better or worse. A 3000-pixel-wide photo tagged at 300 DPI prints 10 inches wide. The exact same file at 150 DPI prints 20 inches wide. Same pixels, same detail — different size on paper.
DPI is simply a label that tells the printer how densely to pack the pixels you already have. Changing it never adds detail, sharpness or color, and it never removes any either — it cannot turn a small, soft photo into a crisp poster. Only pixel dimensions decide quality: a 4000-pixel-wide image always carries more detail than a 1000-pixel-wide one, whatever the DPI tag says. This tool rewrites that label and nothing else, which is why the download is byte-identical in pixels and barely changes in file size.
Tips
- 300 DPI for print, 72 for web. Print shops and photo labs expect 300 DPI for crisp photos. For the web it barely matters — screens ignore DPI — but 72 is the harmless classic.
- Check before you change. Upload first and read the current value — many cameras and phones already tag 72 or 300 DPI, so there may be nothing to fix.
- Raising DPI never adds detail. If a printer complains your image is “low resolution”, re-tagging it won’t help — you need more pixels, not a bigger number on the label.
- Normalize scanner output. Scans often arrive tagged at odd values like 200 or 400 DPI. One click here brings them to the standard 300.
- Your original is never overwritten. The download gets a new name, like photo-300dpi.jpg, so the original file stays exactly as it was.
Common uses
- Print shop files — many labs check DPI before accepting an order; tagging 300 gets yours through.
- Photo books & posters — lay-flat books and wall prints render at the DPI you set.
- Passport & ID photo prints — photo kiosks print at the tagged size; pair with 300 DPI for crisp output.
- Removing “72 DPI” warnings — stock sites and printers flag 72 DPI uploads; re-tag to 300 without touching a pixel.
- Large-format prints — set 150 DPI for banners and wall art, where viewing distance forgives lower density.