BMP to PNG
From bloated DIB to portable PNG
Screen captures and legacy scanners often land as uncompressed BMP. Re-encoding to PNG typically slashes disk usage while keeping pixels lossless (especially for UI screenshots with large flat regions).
Alpha expectations
24-bit BMP has no transparency; 32-bit BMP may carry premultiplied alpha depending on source—spot-check edges after conversion. Next hop for the web: PNG to WEBP.