Image DPI Checker

Read the DPI stored in a photo file

Pixel dimensions tell you how many samples the image contains. Embedded DPI, often called PPI for an image, is a density tag that a compatible layout app can use to place those pixels at a physical size. A file may have no density tag even when it contains enough pixels to print well.

This checker reads JFIF and EXIF density in JPEG, the physical pixel dimensions chunk and EXIF in PNG, EXIF in WebP, the first TIFF directory, and physical resolution in a BMP header. GIF and files with only a pixel aspect ratio can still be measured in pixels. Their embedded density reads Not found.

• JPEG JFIF format
• PNG physical pixel dimensions

Check images placed inside a PDF

A PDF page has physical dimensions and may contain several images. Each image has its own effective PPI, which depends on how large it was placed on that page. For example, 1,200 × 800 pixels placed at 6 × 4 inches provide 200 PPI along both axes.

The checker reports image placement dimensions, with separate horizontal and vertical values when an image is stretched. Text and vector shapes scale independently of raster resolution. The checker inspects up to 50 pages per file and flags pages or placements it could not measure. A batch CSV includes those statuses.

Calculate effective PPI for your paper

Effective PPI depends on the pixels used at the planned print size. A landscape 1,200 × 800 px photo on 10×8 inch paper keeps 1,000 × 800 px when filled and prints at 100 PPI. Fit uses the full width, prints the image at 10×6.67 inches, and gives 120 PPI with white space above and below.

Enter the paper dimensions in the same orientation as the intended print. Change the paper size to see what happens to detail. Pick a smaller print or a less aggressive crop when the number falls below what your lab recommends.

Check what the print lab is asking for

When a lab asks for a 300 DPI file, start with its required pixel dimensions and output size. A portrait 4×6 inch print at 300 PPI needs 1,200 × 1,800 pixels. A file marked 72 DPI with that many pixels can still have 300 effective PPI when printed at 4×6.

Changing a density tag alone affects the suggested physical size. Exporting at a higher target density may also resize the file. When the export needs more pixels than the crop contains, the added pixels are interpolated. Check effective PPI to judge the detail available in the original.

Understand different numbers for the same photo

A JPEG can carry separate EXIF and JFIF values. If they disagree, image apps may choose different tags. Use the labeled sources to see the conflict, then use the lab's specified dimensions to decide how large to print. A single file can also declare different horizontal and vertical densities.

A rotating EXIF tag can swap the displayed width and height. This checker uses the displayed orientation for the print calculation. If an editor, camera, or sharing app removes the density tags, you can still use the pixel dimensions to calculate how that copy will print.