Change Image DPI
Set the DPI of a JPG or PNG, such as 300 DPI for forms and printing, without touching its pixels or quality.
Your files never leave your device. Processing happens in your browser.
How to use the Change DPI
- Upload a JPG or PNG (other formats are converted to JPG).
- Enter the DPI or tap a common value like 200 or 300.
- Click Set DPI and check the new print size.
- Download the image.
What DPI actually is
DPI (dots per inch) is a tag inside an image file that tells printers and some software how big to print it. A 600 × 600 pixel image at 300 DPI prints at 2 × 2 inches; the same pixels at 100 DPI print at 6 × 6 inches. On a screen, DPI makes no difference at all: the pixels are what you see.
Why forms ask for a specific DPI
Some exam and government portals, and many print shops, check that a photo or signature is “200 DPI” or “300 DPI”. Phones and editing apps often save images at 72 or 96 DPI, or with no DPI at all, which can fail these checks even when the image looks perfect. This tool changes just that tag.
Lossless: pixels are not touched
For JPG and PNG, the tool edits the DPI field directly in the file. It does not re-compress the image, so quality is identical and the file size changes by only a few bytes. The pixel dimensions stay the same, and the new print size is shown so you can confirm it.
DPI vs resolution
Changing DPI does not add detail. If a form requires “300 DPI and 3.5 × 4.5 cm”, the image must also be 413 × 531 pixels. Use the image resizer, which sets pixels from centimetres and writes the DPI in one go, or the exam resizer for exam presets.
Common DPI values
- 72–96 DPI: screen default, no significance for printing.
- 200 DPI: often requested for exam photos, signatures and thumb impressions.
- 300 DPI: standard print quality for photos and documents.
- 600 DPI: fine scans of text and line art.
Private
The change happens in your browser, and your file is never uploaded.
Check the result
On Windows, right-click the file, open Properties, then Details to see the resolution. On a Mac, open it in Preview and check the Inspector.
Frequently asked questions
Does changing DPI improve quality?
Will changing DPI change my file size?
How do I make a 300 DPI photo for a form?
Can I change DPI of a WebP or HEIC image?
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