Use dimensions that match your display
For a picture rendered around 800 CSS pixels wide, exporting a moderately larger source may look sharp on many high-density displays. Avoid using a full-resolution camera photo when it will only appear as a tiny thumbnail.
Preserve the intended crop
A square avatar, 16:9 thumbnail and tall story are different layouts. Cropping to the correct ratio before resizing avoids distortion and awkward white padding. Use crop image to select the important region.
Pick a suitable format
Use JPG or WebP for many photographs. Use PNG when you need precise graphics or transparent pixels. Compare output bytes, visible quality and browser compatibility rather than choosing on file extension alone.
Batch processing makes repeat work easier
For a folder of product photos, set a shared maximum width and export through Bulk Image Resizer. This version preserves proportions and creates a ZIP of results in the browser.