The exact WCAG ratio for a colour pair, which thresholds it passes, and the APCA draft number.
Paste a palette, one colour per line, as NAME #HEX or a bare hex. Every text-on-background pairing is graded at once.
AAA passes 7:1, AA passes 4.5:1, AA LG passes 3:1 for large text only. Diagonal cells compare a colour against itself and are skipped.