Quick-set to 72 DPI for web-optimized images. Screen display only needs 72-96 DPI as monitors have fixed pixel density.
Does changing DPI change image quality?
Changing DPI metadata alone doesn't add or remove pixels. It tells printers and software how large to render the image. To increase quality, you need more pixels.
What DPI should I use?
Web/screen: 72-96 DPI. Home printing: 150 DPI. Professional print: 300 DPI. Fine art/archival: 600+ DPI. Higher DPI means more detail per inch when printed.