DPI is a metadata field, not a pixel property — an image at 300 DPI has the same pixels as the same image at 72 DPI, just different metadata. Some platforms (print vendors, visa applications, academic submissions) reject files that don't declare a specific DPI. This tool sets DPI to any target (72, 150, 300, 600) without resampling — pixels stay byte-identical.
DPI is metadata
DPI (dots per inch) tells a printer how many pixels to cram into an inch. The pixels themselves don't change — only the printed size. A 3000×2000 image at 300 DPI prints as 10×6.67 inches; the same image at 150 DPI prints as 20×13.3 inches (larger, softer). Neither is 'higher quality' in the pixel sense.
When to change DPI
Print vendors: usually 300 DPI. Digital display: 72 or 96 DPI. Some visa/document systems: 300 DPI required. If a platform rejects your image citing DPI, this tool fixes the metadata; if it rejects citing pixel dimensions, you actually need to resize (use the Image Resizer instead).
Batch and metadata preservation
Apply the same DPI to a batch. Other metadata (EXIF, IPTC, XMP) is preserved by default; toggle strip options if you want to clean up more.