Dimensions count pixels. File size counts stored bytes. Format, quality, metadata, and image complexity connect them, but not with a fixed formula.
Do it here
Resize an image precisely
Change pixels, not just file size. Lock the aspect ratio or set an exact canvas and output format.
Drop an image here
or paste from your clipboard
Processed securely on our server. Files auto-delete within four hours.
Dimensions
A 1600 by 900 image has 1.44 million pixels. Its displayed size may be smaller or larger depending on CSS, screen density, print settings, or the app showing it.
File size
A 1600 by 900 flat graphic can compress very differently from a noisy night photograph. File bytes include compressed pixels, metadata, color profiles, and container overhead.
Which tool to choose
Use Resize when a platform requires exact width and height. Use Exact Size when it requires a KB or MB cap. Use both when the destination specifies both constraints.