Image DPI Converter
Change the DPI of an image, with or without resampling the pixels.
Runs entirely in your browser.
Your data never leaves this device and is never sent to our servers.
Drop a JPEG or PNG
or click to choose a file · processed on your device
—
Nothing is uploaded — the file bytes are edited in your browser.
DPI is a printing instruction, not a property of the pixels. A 1200 by 1800 image is 1200 by 1800 whether it is tagged 72 or 300 DPI — the tag only says how large to print it. At 300 DPI that image prints at 4 by 6 inches; at 72 DPI the same pixels print at about 16.7 by 25 inches, and look coarse.
That is why this tool offers two modes. Metadata only changes the tag and leaves every pixel alone, which is what print shops asking for "300 DPI" almost always need. Resample changes the pixel count to hold the physical size, which genuinely alters the image.
How to use it
- Drop in a JPEG or PNG.
- Enter the DPI you need — 300 for print, 72 or 96 for screen.
- Choose metadata-only, or resample to keep the print size.
- Check the print-size readout, then download.
Not working as you expect? Report a problem with this tool.
Frequently asked questions
Does changing DPI improve image quality?
No. On its own it changes a number in the file header and nothing else. Quality comes from pixel count: an image with too few pixels stays soft no matter what DPI it is labelled.
My printer asked for 300 DPI — what do I do?
Use metadata-only mode and set 300. Then check the print-size readout: if it is smaller than you need, the image genuinely lacks pixels and must be re-exported larger from the source.
What is the difference between the two modes?
Metadata-only rewrites the density tag and leaves the pixels identical — the file size barely changes. Resample recalculates the pixels so the physical print size stays the same, which means interpolating detail that was never captured.
Does it work for PNG as well as JPEG?
Yes. JPEG stores density in the JFIF APP0 segment; PNG stores pixels-per-metre in a pHYs chunk. Both are rewritten correctly, including adding the chunk when a PNG has none.
Why is 72 DPI mentioned so often for screens?
It is a historical figure from early Macintosh displays. Modern screens vary widely and browsers ignore the tag entirely, so for web use the DPI value is irrelevant — only pixel dimensions matter.