It compares two blocks of text line by line and shows which lines were added, removed, or left unchanged.
Added lines are shown with a green plus sign, removed lines are shown with a red minus sign and strikethrough, and unchanged lines are shown in gray.
When enabled, it treats lines that only differ in letter casing as identical rather than flagging them as changed.
When enabled, it trims and collapses extra whitespace in each line before comparing, so purely whitespace differences are not flagged.
Yes, the "Copy Diff" button copies the full comparison as plain text with +/- prefixes, similar to a standard diff format.