DPI Checker
Drop in an image and this online DPI checker reads its pixel dimensions and the DPI tag stored in the file header. Everything happens in your browser — the file is never uploaded.
Used to work out the effective DPI at the size you plan to print.
Pick a file to read its metadata.
effective DPI = pixel width ÷ printed width in inches How to tell DPI of an image
Two different numbers answer that question. The tagged DPI is a value stored in the file header — the JFIF density block in a JPEG, or the pHYs chunk in a PNG. The effective DPI is the one that matters: pixel width divided by the width you actually print.
Many files carry no density tag at all, and plenty carry a meaningless 72 written by a screenshot tool or an export preset. A missing tag does not mean the image is low resolution; only the pixel count decides that.
Worked with the values in the calculator above
effective DPI = — px ÷ 8.5 in = — DPI At the density above
One inch square at 96 PPI
96 × 96 = 9,216 pixels fill this square.
How to determine DPI of an image without this tool
On Windows, right-click the file, choose Properties and open the Details tab, where horizontal and vertical resolution are listed. On macOS, open the file in Preview and choose Tools then Show Inspector. In Photoshop, Image then Image Size shows both the pixel dimensions and the resolution field.
All of these report the tag rather than the real print density, which is why the checker above also asks for the size you intend to print.
Frequently asked questions
Why does a PNG report 11,811 instead of 300?
Because the PNG pHYs chunk stores density in pixels per metre, not per inch. 300 × 39.37 is 11,811, so a tool showing the raw chunk reports that for a 300 DPI file. Divide by 39.37 to get back to DPI.
How do I check the DPI of an image online?
Use the checker on this page. It parses the JPEG JFIF and EXIF headers and the PNG pHYs chunk locally in your browser, so no file is sent anywhere.
How do I find DPI of an image?
Read the density tag with the checker above, or divide the pixel width by the width you intend to print. The second number governs how the print actually looks.
Why does my image show 72 DPI?
72 is the default many editors and screenshot tools write when no meaningful density is set. It says nothing about quality — a 6000 pixel wide file tagged 72 DPI still prints beautifully at 300 DPI.
How do I check the PPI of an image?
It is the same measurement. Whatever the file calls it, divide the pixels along an edge by the physical length of that edge to get the real pixels per inch.