ClanWarden

Head to head

Two tags, one answer. ClanWarden scores both accounts the same way it scores one, then puts them next to each other so the argument ends.

VS
Rush Score, both sides

The same 0–100 our player pages use: heroes, troops and spells against the caps for that Town Hall, not the game's global maximums.

Section by section

Heroes, equipment, troops, spells, war. Somebody can lose overall and still win the row that started the argument.

Clans too

Two clan tags compares rosters instead, which is useful the day before a war, when you want to know what you are walking into.

Nobody signs in. Both tags are public Clash data, and the result is a link you can paste anywhere.