Image DPI Changer
Set a JPG or PNG to 300 DPI (or any value) without changing its pixels.
About this tool
Open a JPG or PNG to see its pixel size and current DPI. Enter a new DPI or tap a common value, check the print size it gives, and save a copy. Only the resolution setting inside the file changes, and the pixels stay exactly the same.
What DPI really means
DPI (dots per inch), more accurately PPI (pixels per inch) for digital images, is a setting stored inside an image file that tells printers and page-layout apps how many pixels to fit into each inch of paper. It doesn't change the image itself. The detail is in the pixel count. A 3000 × 2400 pixel photo labelled 300 DPI prints at 10 × 8 inches, while the same pixels labelled 72 DPI would print at about 41.7 × 33.3 inches, just much softer up close. Print shops, publishers, photo labs and many application portals ask for "300 DPI" because 300 pixels per inch looks sharp at normal reading distance. Phone photos and screenshots often carry 72 or 96 DPI, or no value at all, so forms reject them even when they have plenty of pixels. Changing the DPI setting fixes that without any loss of quality. For JPEGs this tool rewrites the JFIF density, adding a JFIF header if there isn't one, and the EXIF X/Y resolution that Photoshop and many viewers read. For PNGs it writes the pHYs chunk. Honest limits: raising the DPI number doesn't add detail. If the print size at 300 DPI is smaller than you need, you need a larger original or an upscaled version. Some apps and websites ignore DPI entirely and only look at pixels. The DPI calculator, the image resizer and the image upscaler are related, and What DPI you actually need for printing explains how much resolution prints need.
Frequently asked questions
How do I change an image to 300 DPI?
Open it here, enter 300 and save. The pixels are unchanged, and only the stored resolution is updated.
Does changing DPI reduce quality?
No. The image isn't resampled, so its pixels and quality are exactly the same.
What size will my image print at 300 DPI?
Divide the pixel width and height by 300 to get inches. The tool shows this, in centimetres too, as you type.
Is my image uploaded?
No. The file is edited in your browser and never leaves your device.