This rule has been archived
Archived Reason: Merged to https://www.ssw.com.au/rules/image-formats
Never use bitmap images (.BMP format) on your website or in emails. BMP is an uncompressed format, and typically has an unlimited color palette. This results in unnecessarily large file sizes, which makes it unsuitable for pretty much everything.
As an alternative, the most ideal format for Internet-ready lossless images is PNG.