Image DPI Changer

Set an image's declared print density

Select JPG or PNG images and enter a whole-number target DPI. One updated image downloads directly as JPG or PNG, with the target DPI in its filename. Multiple images download together as a ZIP. Review the summary of pixel dimensions and resulting print sizes. The compressed image data is preserved; this operation changes density metadata rather than resizing or sharpening the photo.

DPI does not create image detail

The term DPI is commonly used in image workflows for the print-density setting, although image pixels per inch and printer dots per inch describe different things. A 600-by-300-pixel image still has 180,000 pixels after this change. Tagging it at a higher density makes its declared printed dimensions smaller. It cannot turn a small screenshot into a detailed large-format photograph.

Worked example: preparing a small print

Set a 600-by-300-pixel image to 300 DPI. Dividing each dimension by 300 gives a declared size of 2 by 1 inches. At 150 DPI, the same pixels correspond to 4 by 2 inches. Both outputs retain the same pixel dimensions. A print application that overrides density or fits the image to a page may print at a different size, so check its placement settings too.

What changes inside the file

JPEG output receives a JFIF density record in inches, and existing EXIF resolution fields are updated to agree. PNG stores physical density in whole pixels per meter, so the requested DPI is converted and rounded to that unit. Existing PNG EXIF density fields are updated when present. The tool preserves compressed image payloads and recalculates checksums for changed PNG metadata chunks. It does not perform another lossy JPEG compression.

Use the print-size summary

Before submitting an image, compare its available pixels with the required physical dimensions. Changing a metadata value alone will not satisfy a genuine minimum-pixel requirement. The summary reports decoded dimensions; an image carrying an orientation tag may be displayed with width and height swapped by a viewer. When a printer requests specific dimensions, confirm the oriented layout in that printer's preview.

Limitations and privacy

Inputs are limited to 20 JPG or PNG files, 80 MB combined, and 24 million pixels per image. Targets range from 1 to 2400 whole DPI. Empty files, corrupted PNG checksums, and unsupported EXIF structures produce an error instead of an uncertain metadata edit. The tool preserves other metadata, which can include camera or location information. Use a metadata-removal tool separately if you intend to remove that information.