Reduce unnecessary pixel dimensions and preserve the alpha channel when preparing a transparent PNG for a web graphic.
Find what makes the file large
PNG file size depends on dimensions and image complexity, not only on the transparent area. A detailed photograph can remain relatively large after its background is removed. Deleting the background does not guarantee a smaller download than the original JPG, because JPG and PNG use different compression methods.
Resize for the actual placement
Keep the original cutout as a master. In an editor, make a delivery copy sized for its intended use. A small profile card does not need the same dimensions as a full-width design. Preserve proportions and inspect the result after resizing so hair and outlines do not become distracting. Avoid repeatedly enlarging and reducing the same copy.
For instance, a subject displayed at a few hundred pixels wide may not need a 2,048-pixel export in the final page. Choose dimensions based on the display and desired sharpness rather than a universal file-size target.
Keep transparency through optimization
Use an export format and settings that retain alpha. PNG is a straightforward master format; some destinations support transparent WebP as well. Verify the receiving application rather than assuming all apps preserve it. Converting to JPG removes transparency and requires a flat background. After any optimization, reopen the file on a colored layer and compare both the edge quality and file size. A smaller file is only useful if it still serves the design correctly.