Paste a Commander, Brawl or 60-card list. You get the weakest slots with a reason for each, the cards the format's best lists run instead, a Karsten land count and any legality problems, in about a second. No install, no account.
Legality first: cards not legal in the format, outside the commander's colour identity, or over the copy limit are always cut. Then role quotas: when a deck runs more removal, draw or ramp than the format's band, the weakest cards in that role are flagged. In commander formats, cards with no synergy edges to the commander or the rest of the deck rank next; in 60-card formats, cards absent from the current meta top list. Lands are never cut here: the land target uses Karsten's formula (lands = 19.59 + 1.90 × average mana value − 0.28 × cheap ramp/draw spells (60-card deck)).
Adds come from role gaps, cards that co-occur with yours in nearly 4 million public decks, commander inclusion rates, and the format's meta staples. With a saved collection, owned cards are listed first. Full method on the methodology page.