Check the DPI of an Image
See the DPI saved inside a PNG, JPG or WebP file, and how big it prints at that DPI and at 300 DPI. Need a different number? Save a copy with a new DPI: only the label changes, and every pixel stays exactly the same.
- 1Choose an image
- 2Read the DPI
- 3Change it if needed
1Choose an image
PNG, JPG or WebP. Drop it here, or paste with Ctrl/Cmd+V
Print size
| At | Inches | Centimetres |
|---|
Where the DPI is stored
Your image never leaves your device. It is read in your browser. We count visits and finished downloads (tool name only) with analytics that sets no cookies.
How to check the DPI of an image
- Choose your image. Drop a PNG, JPG or WebP on the box above, paste it, or press Choose image.
- Read the DPI. The big number is the DPI saved in the file. If the file has no DPI, the tool says so.
- Check the print size. The table shows how big the image prints at its saved DPI and at 300 DPI, in inches and centimetres.
- Change it if you need to. Type a new DPI or press 72, 96, 150, 300 or 600, then download the copy. Your original file is not changed.
DPI is a label, not a quality setting
A digital image is a grid of pixels. The DPI saved in the file only says how many of those pixels should fill one inch when it is printed. Changing it does not add or remove pixels, so the image looks exactly the same on screen. It only changes the print size an app suggests: print size in inches = pixels ÷ DPI.
So a photo 3000 px wide prints 10 inches wide at 300 DPI, or 20 inches wide at 150 DPI. To print bigger at the same DPI, you need an image with more pixels. Our guide how many pixels are in an inch explains this with tables, and the Pixels to Inches converter works out the pixels you need for any print size.
If a print shop or form asks for a DPI, use their number. Check the print size at that DPI is the size you want; if it is too small, the image needs more pixels, not a new label.
Where the DPI is stored
- PNG: the
pHYschunk stores pixels per metre, so 300 DPI is saved as 11811 pixels per metre and reads back as 299.99. Some PNGs also carry the DPI in Exif data (eXIf); this tool reads and updates both. - JPG: the JFIF header stores whole dots per inch or per centimetre, and Exif data stores XResolution and YResolution. A file can have one, both or neither. When both are there, they can disagree; the download sets both to your new value.
- WebP: the format has no DPI field of its own. A DPI can only be kept in its Exif data, and not every app reads it. The download adds or updates that Exif data.
The image data (the compressed pixels) is copied byte for byte. Nothing is decoded and saved again, so a JPG does not lose quality, and other metadata such as colour profiles is kept.
FAQ
How do I find out the DPI of an image?
Choose the image above. The tool reads the DPI saved in the file and shows it as the big number, with where it was found: the PNG pHYs chunk, the JPG JFIF header or the Exif data.
How do I know if my image is 300 DPI?
Open it here: if the big number says 300 DPI, the file is labelled 300 DPI. What matters for a print is whether it has enough pixels for your print size at 300 DPI; the second row of the print-size table shows that size.
How do I convert a JPG to 300 DPI?
Choose the JPG, leave the new DPI at 300 and press Download with 300 DPI. The copy is labelled 300 DPI and has the same pixels as your original, with no re-compression.
Why does my image say "no DPI stored"?
The file was saved without one: plenty of apps and websites leave it out. When there is no DPI, the app you print from decides the size. Set a DPI here if you want the file itself to say how big it should print.
Will changing the DPI make my image better quality?
No. The pixels are not touched, so the image looks the same everywhere. A higher DPI only makes the suggested print smaller and denser. To get a bigger print at the same DPI you need more pixels, for example the original photo instead of a copy saved from the web.
Does this tool upload my image?
No. The file is read and rewritten by your browser on your own device and is never sent to a server. You can check: open your browser's developer tools, go to the Network tab, and use the tool. The page counts visits and finished downloads (tool name only) with analytics that sets no cookies, and no image data is ever sent (see privacy).