Image DPI Tool

DPI (dots per inch) is one of the most misunderstood concepts in digital imaging. It's not a property of the image itself — it's metadata that tells a printer how large to print each pixel. A 3000×3000 image is 3000×3000 pixels regardless of its DPI setting; the DPI only affects what physical size that image will be when printed. At 300 DPI, that image prints at 10×10 inches. At 72 DPI, it prints at 41×41 inches. Same pixels, different physical output.

This causes endless confusion. People ask 'how do I make my image higher DPI?' expecting a sharper image. The answer is: you can change the DPI metadata (which we do here), but you can't add detail that isn't there. A 300×300 image at 300 DPI prints at 1×1 inch and looks blocky. A 3000×3000 image at 300 DPI prints at 10×10 inches and looks sharp. Both have the same DPI setting — the difference is pixel resolution.

This tool sets the DPI metadata without resampling. That's the right choice when you need to match a print pipeline's expected DPI (most professional print shops require 300 DPI in the file's metadata) without changing the actual pixels. If you need to actually increase or decrease the pixel count, use Image Resizer instead — DPI changes there can resample, but the result is different pixels, not the same pixels with a different label.