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Open Img Stop Change Image DPI, add your JPG or PNG and select 72, 96, 150, 200, 300, 600 or Custom. Click Change DPI and download the file. Only the DPI value is changed; the pixels stay exactly the same, and the print size is shown in inches and cm.
About the Change Image DPI
Img Stop Change Image DPI writes a new DPI (dots per inch) value into the file. For JPG it updates the JFIF header, and for PNG it writes the pHYs chunk. The image data is not re-saved, so there is zero quality loss and the pixel width and height do not change. Other formats such as WebP are first saved as a high quality JPG.
DPI tells printers and programs like Word or Photoshop how large to print the image. Many official forms, print shops and publishers ask for 300 DPI. The tool shows the print size for your chosen DPI, for example 1200×1800 pixels at 300 DPI prints at 4×6 inches. Lower DPI means a bigger print; higher DPI means a smaller, denser one.
Key features
- Common presetsOne click for 72, 96, 150, 200, 300 or 600 DPI.
- Custom DPIEnter any value from 1 to 65535.
- No quality lossJPG and PNG are not re-encoded; only the DPI field is changed.
- Print size shownSee the printed width and height in inches and centimeters.
- JPG and PNG supportWorks with both, and saves other formats as JPG.
- Batch changeSet the same DPI on many images and download them as a ZIP.
How to use the Change Image DPI
- Add your images Drop JPG or PNG files on the box, click Choose files, or paste with Ctrl+V.
- Choose the DPI Click a preset such as 300, or choose Custom and type the DPI you need.
- Change and check Click Change DPI. Read the print size shown under each result.
- Download Download each file, or all files at once with Download all (ZIP).
Change Image DPI at a glance
| Price | Free |
|---|---|
| Input formats | JPG, PNG (other images saved as JPG) |
| Output formats | JPG or PNG |
| DPI presets | 72, 96, 150, 200, 300, 600, custom 1–65535 |
| Quality loss | None for JPG and PNG – pixels unchanged |
| Processing | In your browser – files are not uploaded |
When to use it
- Set a photo to 300 DPI when an online application or print shop asks for it.
- Prepare images for a book, magazine or brochure that requires 300 or 600 DPI.
- Fix images that open too large or too small when placed in Word or a design program.
- Check how big a photo will print before ordering prints.
- Change screenshots from 72 or 96 DPI to 300 DPI for a report.
Tips for the best result
- Changing DPI does not add detail. For a sharp 300 DPI print, the image needs enough pixels: about 300 pixels per printed inch.
- If the print size shown is too small, enlarge the pixels first with Resize Image or Image Enlarger, then set the DPI.
- For screens and websites DPI does not matter; only the pixel size counts.
Frequently asked questions
How do I convert a JPG to 300 DPI?
Add the JPG, click 300 and press Change DPI. The tool writes 300 DPI into the file header without changing the pixels, so the photo looks exactly the same. Download the new file and it will report 300 DPI in Windows, Mac, Word and Photoshop.
Does changing DPI improve image quality?
No. DPI is only a print instruction. The pixels stay the same, so the photo looks identical on screen. What changes is the printed size: at higher DPI, the same pixels are packed into a smaller area, which prints sharper but smaller.
What is the difference between DPI and resolution?
Resolution usually means the pixel size, like 3000×2000. DPI says how many pixels go into one printed inch. A 3000 pixel wide photo at 300 DPI prints 10 inches wide. To get more detail you need more pixels, not just a higher DPI number.
Will my image size in KB change?
Almost not. For JPG and PNG only a few bytes in the header change, so the file size stays nearly the same. If you add a WebP or another format, it is converted to JPG at high quality, which may change the size.
What DPI do I need for printing?
Most photo prints, books and official documents use 300 DPI. Large posters viewed from far away can use 150 DPI. Fine art and line drawings sometimes use 600 DPI. Always check what your printer or form asks for.
Last updated October 29, 2026 by the Img Stop team.