Printers, scanners, and stock photo sites all care about DPI — yet most image editors bury the setting three dialogs deep. This guide shows four ways to change the DPI of an image, from a free browser tool to Photoshop, and explains which one you actually need.
What changing DPI really does
DPI (dots per inch) is metadata: it tells the printer how densely to place the image's pixels on paper. Changing DPI does not add or remove pixels — the image data stays byte-for-byte identical. What changes is the physical print size implied for the same pixel count.
A 3,000 × 2,000 pixel photo prints at 10 × 6.67 inches at 300 DPI, or 30 × 20 inches at 100 DPI. Same pixels, different paper.
Option 1: Free in your browser (fastest)
Open the DPI Converter, drag your image in, pick 300 DPI (or any value from 72 to 600), and click Convert. The new file downloads instantly with the correct DPI written into its metadata. Everything runs locally — the image never leaves your device.
- Works with JPG, PNG, WebP, BMP, TIFF, and GIF
- Batch mode converts up to 50 images at once
- Live preview shows the resulting print size
Option 2: Windows (Paint)
- Open the image in Paint.
- Click File → Properties and set the resolution units to pixels/inch.
- Re-save as PNG or JPEG — Paint writes the new DPI into the file.
Option 3: macOS (Preview)
- Open the image in Preview.
- Choose Tools → Adjust Size….
- Switch the units to pixels/inch, enter the new DPI, and export.
Option 4: Photoshop
Run Image → Image Size, uncheck Resample, and change the Resolution field. Because resampling is off, pixel data is untouched — only the DPI metadata changes. Click OK and save a copy.
Which DPI should you use?
| DPI | Best for |
|---|---|
| 72–96 | Web, screens, email |
| 150 | Draft prints, posters viewed from afar |
| 300 | Photos, documents — the print standard |
| 600 | Fine art and professional prepress |
Unsure what pixel dimensions your print size needs? The DPI calculator works it out in one step.
FAQ
Does changing DPI reduce quality?
No. As long as resampling is off, not a single pixel is modified. Quality only drops when pixels are added or removed during a resize.
Will the printer use the new DPI automatically?
Yes — the print dialog reads the DPI from the file metadata and uses it to scale the image, unless you override the size manually.