Check the DPI of an Image

How is DPI stored in an image?

DPI (dots per inch) is a metadata value baked into the image file - it does not change how many pixels the image contains. JPEG files store DPI in a small JFIF header or in EXIF tags. PNG files store it in an optional pHYs chunk (in pixels per metre, which we convert to DPI). TIFF files store horizontal and vertical resolution in their IFD tags 282 and 283.

Why does my image show 72 DPI or 96 DPI?

When an image has no DPI metadata, software fills in a default. Windows (and Windows Explorer’s “Horizontal resolution” field) assumes 96 DPI; Photoshop and most web/Mac tools assume 72. That is why the same file can read as 72 in one program and 96 in another - neither value is actually stored in the file. The pixel count is identical either way, and DPI only affects the image when it is printed.

Why does my image show no DPI at all?

Some files genuinely have no DPI field set. We show the source of the value so you can tell whether it came from a real header, EXIF, or a fallback assumption.

Is my image uploaded anywhere?

No. The image is read inside your browser and never leaves your device.