Image DPI Changer
See the DPI of a JPG or PNG and change it to 200, 300 or any value without quality loss
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How to Use
- Drop one or more JPG or PNG files on the box. Each file shows the DPI stored in it now, its size in pixels and how big it would print.
- Pick the New DPI: 72, 96, 150, 200, 300, 600 or Custom. Under each file you'll see the print size at the new DPI.
- Leave DPI only (no quality loss) selected to change just the number. Choose Resize to a print size if you need an exact size in cm or inches; then enter the width and height, pick the Shape (Exact width and height trims the edges if needed, Keep proportions never trims) and, for JPGs, the quality.
- Tap the Set DPI button (it shows the number you picked, for example Set 300 DPI).
- Download each file with its download button, or tap Download all as ZIP when you've done several.
What this image DPI changer does
This image DPI changer lets you change the DPI of an image. It shows the DPI saved inside a JPG or PNG and sets a new one, such as 200 or 300 DPI. By default it changes only that number in the file's header and copies the picture data byte for byte, so the photo looks exactly the same. If a form wants a fixed print size, for example 3.5 × 4.5 cm at 200 DPI, it can also resize the image to the right number of pixels and stamp the DPI on it.
Everything happens in your browser. Your photo, signature or scanned certificate isn't uploaded anywhere.
What DPI actually means
DPI stands for dots per inch. A digital image has no inches, only pixels. The DPI value is a note inside the file that tells a printer or a page-layout program how many of those pixels to fit into one inch of paper. Change it and the pixels stay the same; only the suggested print size changes.
print width (cm) = width in pixels ÷ DPI × 2.54
pixels needed = size in cm ÷ 2.54 × DPI
So on a phone or computer screen, a 300 DPI photo and a 72 DPI copy of the same photo look identical. The difference shows up only when you print, or when a website checks the number.
A worked example
A phone photo of 3000 × 4000 pixels is often saved at 72 DPI. At 72 DPI it would print 105.8 × 141.1 cm, the size of a poster. Set it to 300 DPI and the same pixels print at 25.4 × 33.9 cm. Nothing in the picture changed.
Now say a form asks for a 3.5 × 2.5 cm photo at 200 DPI. The pixels needed are 3.5 ÷ 2.54 × 200 = 276 by 2.5 ÷ 2.54 × 200 = 197. Use Resize to a print size with those centimetres and 200 DPI and you get a 276 × 197 pixel image marked 200 DPI.
Why forms ask for 200 or 300 DPI
Many Indian application portals and scanning instructions mention a DPI. For example, the IBPS and SBI 2026 notifications ask for the thumb impression and handwritten declaration to be scanned at 200 DPI, and Protean (NSDL) asks for PAN photos and signatures scanned at 200 DPI. When a portal also gives a size in pixels or KB, those limits matter more than the DPI number, because the site checks them directly. Always read the latest notification for your exam or service.
| DPI | Where it's used |
|---|---|
| 72 or 96 | Screens. Many phones and editing apps save this by default. |
| 150 | Draft prints and quick scans where file size matters more than detail. |
| 200 | Document scans for many online forms (bank exams, PAN). |
| 300 | Good-quality photo prints, passport-style prints, most print shops. |
| 600 | Detailed scans of fine print, line art and signatures. |
Tips and limits
- Raising the DPI number doesn't add detail. A blurry 400 × 300 photo is still blurry at 600 DPI; it just prints smaller.
- JPG files keep their DPI in a JFIF header and sometimes also in EXIF data. The tool updates both, so every app reads the same value.
- PNG files keep it in a pHYs chunk, stored as pixels per metre, so 300 DPI is saved as 11,811 pixels per metre and some apps show 299.99.
- WebP and HEIC images have no standard DPI field. Convert them to JPG first.
- If a portal rejects the file for size in KB, compress it with our image compressor, or use the exam photo resizer, which handles pixels and KB together.