Check Image DPI and Print Size
Open a photo to read the resolution written in its file, along with its pixel size and the size it would print at 72, 150 and 300 DPI.
Drop an image here to inspect its metadata
JPG, PNG and WebP are read directly in your browser
Nothing is uploaded. Metadata is read and written on this device.
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DPI is one of the most misunderstood numbers in a photo. It does not describe how sharp the image is, and changing it does not add or remove a single pixel. It only describes how large the file should be printed.
This page reads the value that is actually stored in the file.
What DPI really means
A 3000 × 2000 pixel photo printed at 300 DPI fits on a 10 × 6.7 inch sheet. Printed at 150 DPI, the same file covers twice that width. The pixels never change; only the instruction for the printer does.
- Pixels decide how much detail exists.
- DPI decides how densely those pixels are placed on paper.
- Print size is pixels divided by DPI.
That is why a 72 DPI file can still look sharp on screen: screens ignore the DPI field and display pixels one to one.
Where the value is stored
The three supported containers keep it in different places, and a file can even have two values that disagree:
- JPG — the JFIF header, with the EXIF resolution fields as a fallback.
- PNG — the pHYs chunk, stored in pixels per metre and converted to inches.
- WebP — only EXIF, because WebP has no resolution field of its own.
The checker names the source it used, so you know whether you are reading the print instruction or a fallback. When nothing is found, it reports 72 DPI, the conventional screen default, and says so instead of pretending the file declares it.
Reading the print sizes
The page shows the print size at three common values:
- 72 DPI — screen and web, where DPI is ignored anyway.
- 150 DPI — a draft print or a large poster viewed from a distance.
- 300 DPI — the usual target for a photo print.
Each row gives both centimetres and inches, so you can compare against a paper size without converting anything.
Two values in one file
A JPEG can carry its resolution twice: once in the JFIF header written by the encoder, and once in the EXIF block written by the camera or editor. When the two disagree, two programs can show two different numbers for the same file, and both are reading a value that really is stored there.
This checker names the source it used, so the number on screen is traceable rather than a guess. If a print lab insists on one particular value, rewrite it with the DPI converter, which updates both locations in a JPEG instead of only one.
What this page does not do
It does not resample the image, and it does not guess a “correct” DPI. If the print size is wrong, the fix is to rewrite the DPI value, which is what the DPI converter does.
If you also want to see the camera, lens and location stored in the file, the EXIF metadata viewer shows that layer; it can remove the location too.
Frequently asked questions
Where does the DPI value come from?+
JPG files keep it in the JFIF header or in the EXIF resolution fields; PNG files keep it in the pHYs chunk; WebP keeps it in EXIF. The page reports which source it found.
The file shows 72 DPI. Is something wrong?+
No. Browsers and screens ignore DPI, and many exporters write 72 DPI by default. A photo can be perfectly sharp at 72 DPI because sharpness comes from pixel count, not DPI.
Why does the print size differ from what my editor shows?+
The print size is calculated as pixels divided by DPI. If an editor reports a different size, it is probably reading a different DPI value, or scaling the image before printing.
Can I change the DPI here?+
This page only reports. Use the DPI converter to rewrite the value; it changes the print size without resampling the picture.
Which formats can be checked?+
JPG, PNG and WebP. HEIC, TIFF and AVIF are refused with a message because their metadata is stored in a structure this tool does not read yet.
Does changing DPI change the file size?+
Barely. Rewriting the DPI value touches only a header field, so the pixels and the compressed image data stay the same. The file may differ by a few bytes, not by kilobytes.
What DPI should I aim for?+
300 DPI for a photo print held in the hand, 150 for a poster seen from a distance; 72 is only a screen convention. Pixel count still decides sharpness: a 1200 × 800 file cannot print an A4 sheet sharply whatever value the DPI field holds.
Related
Tools
More like this
- Change Image DPI to 300 — Change image DPI to 300, or any value from 72 to 1200, across a whole batch. Only the metadata is rewritten, so pixels and quality stay untouched.
- Remove EXIF Data from Photos — Remove EXIF data from photos: clear GPS location, wipe the whole metadata block, or write copyright and author. Local, and pixels are never re-encoded.