How to check image DPI and resolution
Pixel dimensions tell you how much image data exists. DPI is metadata that can suggest a print scale, and it may not be embedded at all.
Check both the pixel dimensions and the embedded resolution field.
A file can be 4000 × 3000 pixels even if it has no DPI value stored. For digital use, pixel dimensions are usually the more important measurement.
Check image resolution →Pixels
Width × height tells you the actual pixel grid stored in the image.
DPI
DPI metadata is commonly used for print sizing. Changing only the metadata does not magically add image detail.