DPI vs PPI: What's the Difference?
DPI and PPI both describe resolution — but one belongs to the printer and the other to your image. Here's how to tell them apart.The two-minute version
PPI (pixels per inch) measures the pixel density of your digital image at a given print size. It's the number you control when you choose how large to print.
DPI (dots per inch) measures the dot density of the printed output — a property of the printer and its ink, not of your file.
Why the confusion exists
Photo editing software and print shops have used "DPI" to describe file resolution for so long that the two words have blurred together. When a shop says "send us a 300 DPI file," they really mean "send a file that prints at 300 PPI." In practice the advice is identical, which is why this site treats the practical meaning of "300 DPI" as 300 PPI.
A side-by-side table
| Term | What it measures | Where it lives |
|---|---|---|
| PPI | Pixels per inch of print | Your image file |
| DPI | Ink dots per inch | The printer |
Which one should you care about?
For deciding how large to print your photo, PPI is the number that matters. It's what the pixels to inches conversion uses, and it's what determines whether a print looks sharp. The printer's DPI spec, within reason, is the printer's job to worry about.
A high PPI file can't rescue a low-quality printer, and a great printer can't add detail that isn't in your image. Both matter — but they're different links in the chain.