Change the DPI of an image

FreeNo uploadNo signupWorks offline

Set the print resolution recorded in a JPG or PNG to whatever a form, printer or publisher asks for. The tool shows what the file declared before, what it declares now, and whether anything about the pixels actually changed.

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How to use Change Image DPI

Change Image DPI – Set any print resolution, and see what it does to the printed size. Free, no upload.

Choose or drop your image.
Type the resolution you need.
Choose whether to resample the pixels as well.
Click Set resolution and download.

Supported formats

Input: JPG, PNG
Output: JPG, PNG

What DPI actually is

An image file is a grid of pixels and nothing else. It has no physical size until something decides how many of those pixels go into each inch of paper - and that number is the DPI. It is a single value recorded in the file’s metadata: the JFIF density field in a JPG, the pHYs chunk in a PNG. Changing it changes how large the image prints, not how much detail it holds. A 600 × 600 photo tagged 300 DPI prints at two inches square; tag the same file 72 DPI and it prints at just over eight inches, from exactly the same pixels, and looks coarse.

What this can and cannot do

Setting the tag cannot add detail. If a form rejects your photo as "low resolution" because the pixel count is too small, no DPI value will fix that - you need a larger photo. What the tag does fix is the very common case where the image is big enough but the file says 72 DPI and a checker refuses it on that basis. Most tools that advertise a DPI increase are doing exactly this and not telling you. The Resample option is the other case: it resizes the pixels so the printed size stays the same, which is a real change and is reported as one.

Which resolution to use

The values worth knowing, and when each is right.

Common print resolutions
DPI	Used for	A 3.5 × 4.5 cm photo needs
72	Screens and the default when a file records nothing	99 × 128 px
150	Documents read at arm’s length; halves the pixel count	207 × 266 px
300	The standard for anything printed and inspected closely, and what most forms demand	413 × 531 px
600	Fine line art and some archival scanning; rarely needed for photographs	827 × 1063 px

Limitations

JPG and PNG only - other formats cannot record a resolution.
Changing the tag does not add detail.

Privacy

Files you choose are read into your browser’s memory and processed on your device; they are not uploaded to a server. Temporary download links are released after use, and the offline cache never stores your documents. More about privacy and limits.

Frequently asked questions

What DPI should I use?

300 for anything printed and looked at closely, 150 for documents, 72 only for screens. If a form states a figure, use that one.

What is the difference between the two modes?

Set the tag only rewrites a few metadata bytes and leaves every pixel alone. Resample resizes the picture so it keeps the physical size it had at its old resolution - a real change to the image.

Does changing DPI reduce quality?

Setting the tag does not touch the pixels at all. Resampling upward enlarges the picture, and enlarging cannot add detail, so it will look softer.

Is my image uploaded?

No. The file is read in your browser and the few metadata bytes are rewritten on your device. Nothing is sent anywhere.

Is it free?

Yes - free, no signup, no watermark.