FreeDPI Converter
Change image DPI
Set print resolution without resampling the pixels.
Drop an image here, or .
Runs in your browser. Nothing is uploaded.
DPI Converter: how to use it
- Drop in your image.
- Type the DPI you need, usually 300 for print shops and photo labs.
- Choose JPG or PNG and download. The result table shows the print size in inches at that DPI.
Tips
- DPI is only a label that tells printers how big to print. The pixel dimensions stay exactly the same, so this does not make an image sharper.
- If the print size comes out too small at 300 DPI, the image does not have enough pixels for that print. Our DPI and print size guide shows how many you need.
DPI Converter: what it does and when to use it
DPI (dots per inch) is a number stored in the image file that tells a printer how large to print it. It does not change the pixels. A 3000 × 2000 photo marked 300 DPI prints at 10 × 6.7 inches; the very same pixels marked 72 DPI would print at about 41 × 28 inches, and look soft. This tool rewrites that number and leaves every pixel exactly as it was.
That is why it is the right fix when a print shop, a photo lab, or a publisher's upload form says an image must be 300 DPI: they read the header, and many will reject a file marked 72 DPI even if it has plenty of pixels. The table under the result shows the print size at the DPI you chose, so you can check it before sending.
If the print size at 300 DPI comes out smaller than you need, the image simply does not have enough pixels for that print at full sharpness. You can accept a lower DPI (around 150 still looks fine for posters viewed from a distance), or enlarge it first with the AI Image Upscaler. Our DPI and print size guide has a table of common print sizes.
DPI Converter: frequently asked questions
How do I change an image to 300 DPI?
Set 300 and download. Only the DPI number stored in the file changes; the pixels stay exactly as they were. That is all most print shops and publishers mean when they ask for 300 DPI, as long as the image has enough pixels for the print size.
Does changing DPI improve quality?
No. DPI only tells a printer how large to print each pixel. To get more real detail you need more pixels, which means upscaling or a better original. Our DPI and print size guide shows how many pixels each print size needs.
How many pixels do I need for a 4x6 print?
At 300 DPI a 4 by 6 inch print needs 1200 by 1800 pixels. Any recent phone photo has far more than that. An 8 by 10 needs 2400 by 3000.