A double elimination bracket gives every team a second chance. Lose in the winners bracket, you drop to the losers bracket. Lose again, you're out. It's the format of choice for serious tournaments where a single bad game shouldn't decide your run — ACL cornhole, competitive Super Smash, most wrestling tournaments, the Little League World Series.
any size · winners + losers brackets
Two brackets run in parallel: the winners bracket (WB) and the losers bracket (LB). You start in the WB. Lose a match, drop to the LB. Lose in the LB, you're eliminated.
The LB has roughly twice as many rounds as the WB because it has to absorb losers from every WB round. A 16-team double elim has 4 WB rounds and 6 LB rounds before the Grand Final.
The Grand Final pits the WB winner (undefeated) against the LB winner (one loss). If the LB team wins the first Grand Final, a second match is played — the WB team hasn't lost yet. This is called a "bracket reset" and it's why double elim tournaments sometimes have two Grand Finals.
When players drop from the WB into the LB, you don't want them running into the same opponent immediately. Standard practice is cross-seeding: losers from the top half of the WB go to the bottom of the LB, and vice versa. This tool does it automatically.
The goal is fairness — the player who beat you in the WB shouldn't be the one eliminating you in the LB right after.
Don't use DE for huge fields (60+) — the schedule balloons. Don't use DE for a casual one-hour bracket — it's twice as long as single elim.
A DE tournament has approximately 2N − 2 matches for N players, plus potentially one bracket reset. So 16-team DE is ~30 matches; 32-team DE is ~62 matches. Single elim has N − 1 matches, so DE is roughly double.
Plan accordingly. If 30-minute matches × 30 matches = 15 hours, you need either a longer event or parallel matches running on multiple courts or stations.