1
Add your images
One or many JPG or PNG files. Other formats are saved as JPG.
2
Type the DPI
Pick a common value or type the exact number your form or printer asks for.
3
Download
The files keep every pixel; only the DPI value inside them changes.

Why this size

What DPI really is

DPI (dots per inch) is a label stored inside the image file. It tells a printer how large to print the pixels you already have. It does not add or remove detail.

Phones and websites often save photos at 72 or 96 DPI, so a form that checks the DPI rejects them even when the photo is sharp. Changing the label fixes that. The table shows how the same 1200 x 1800 pixel photo prints at different DPI values.

DPI	Prints at	In cm
72 DPI	16.7 x 25.0 in	42.3 x 63.5 cm
150 DPI	8.0 x 12.0 in	20.3 x 30.5 cm
200 DPI	6.0 x 9.0 in	15.2 x 22.9 cm
300 DPI	4.0 x 6.0 in	10.2 x 15.2 cm
600 DPI	2.0 x 3.0 in	5.1 x 7.6 cm

Tips

Tips that make a difference

Need a print size as well?

If a form wants both a DPI and a size in cm, resize in cm first. That tool already writes the DPI.

Your phone shows 72 DPI?

That is only the label most cameras write. The photo itself usually has more than enough pixels for printing.

Avoid

Common problems and fixes

The portal still rejects the photoForms check more than DPI. Check the pixel size and the KB range in the instructions as well.
The photo prints at the wrong sizeDPI decides the print size of the pixels you have. Use the table above, or resize in cm, which sets both.
Changing the DPI did not make it sharperDPI is a label. Only more pixels add detail.

FAQ

DPI Converter: questions

Add the image, pick or type the DPI and download. The pixels stay the same and the file carries the new DPI.

No. JPG and PNG files keep their image data exactly; only a few bytes of the header change.

It depends on the portal. PAN applications on Protean (NSDL) ask for 200 DPI photos and signatures, UTIITSL asks for 300 DPI photos and 600 DPI signatures, and most print shops want 300 DPI.

Cameras and apps write 72 or 96 DPI by default. It is only a label, so you can change it here without losing anything.

Yes. Add up to 5 at a time, or 50 with a free account, and download a ZIP.

No. The change happens in your browser.

Checked

How we checked this page

Checked by the SizePort team on 3 October 2026.

We test the tool with sample photos before it goes live and check that the sizes on this page match what it produces. Rules and platforms change, so if something here is out of date, tell us and we will correct it.

How the tool works

The tool changes only the DPI value stored in the file header. The pixels, the colors and the image data stay exactly as they were, so nothing is re-compressed. Everything happens in your browser; your images are never uploaded.