Random Bracket Generator
Turn any list of entrants into a fair single-elimination bracket — shuffled seeding, correct byes, and a full round-by-round draw.
A bracket looks simple until the entrant count is not a clean power of two. With 5, 12 or 27 entrants, somebody has to sit out the first round — and who gets that bye, and who the top seed meets first, is exactly where a hand-made draw quietly turns unfair. This generator does the whole job properly: paste the entrants, press the button, and it shuffles everyone into seed positions, builds the bracket out to the next power of two, and places the byes where standard seeding says they belong — with the highest seeds.
One entrant per line. The draw shuffles everyone into seeds, places them in standard seed order, and gives any byes to the top seeds.
Want groups instead of head-to-head matches? Use the Random Team Generator. Just need one winner picked, with no tournament? Use the Random Picker.
Quick answers
How does this random bracket generator seed the draw?
Your list is shuffled with cryptographic randomness, the shuffled order becomes seeds 1, 2, 3 and so on, and those seeds are placed using the standard tournament seed order, so seed 1 meets the lowest seed, seed 2 meets the second-lowest, and no two top seeds can meet early.
For an eight-slot bracket the placement order is 1, 8, 5, 4, 3, 6, 7, 2. Adjacent slots form the first-round pairs, and each pair sums to the bracket size plus one. The same pattern extends to 4, 16, 32 and 64 slots, which is what keeps the strongest entrants apart until the late rounds.
Who gets a bye when the entrant count is not a power of two?
The top seeds do. The bracket is built out to the next power of two, and the empty slots — the byes — land opposite the highest seeds because of the standard seed order, so with 12 entrants in a 16-slot bracket, seeds 1 to 4 receive byes.
That is the arrangement used by seeded tournaments in tennis, esports and school competitions alike: a bye is a reward for a high seed, never a random gift. Here the seeds themselves are shuffled, so the byes go to whichever entrants the shuffle happened to seed highest — nobody can arrange one in advance.
How many entrants can the bracket hold?
From 3 to 64 entrants. The bracket size is the next power of two at or above your count: 4, 8, 16, 32 or 64 slots, with any remainder shown as byes.
Two entrants do not need a bracket — that is a single match — and past 64 a single-elimination draw becomes a multi-day event that deserves dedicated tournament software. Clearing duplicate names is deliberate: the same name typed twice is treated as two entrants only if you leave both lines in, so check the count line under the draw.
How to use
- Paste or type the entrants, one per line — teams, players, songs, classroom entries, anything. You need at least 3 and can use up to 64.
- Press Generate bracket. The list is shuffled into seeds and placed in standard seed order.
- Read the draw round by round: first-round matches, any byes (marked BYE), and the winner-of slots for the rounds that follow.
- Use Copy bracket text to take a plain-text version with you, or press Generate bracket again for a completely fresh shuffle.
About this tool
The seeding is the standard tournament kind, not just names poured into slots in order. In an eight-slot bracket the seed order is 1, 8, 5, 4, 3, 6, 7, 2, so the opening pairs are 1 against 8, 5 against 4, 3 against 6 and 7 against 2 — every pair sums to nine, the strongest seed meets the weakest, and the two favourites cannot meet before the final. When byes are needed, the same order hands them to the top seeds automatically: with five entrants in an eight-slot bracket, seeds 1, 2 and 3 receive byes and only seeds 4 and 5 play an opening match. That is the arrangement real tournaments use, and it falls out of the seed order rather than a special case.
The shuffle itself uses the browser cryptographic random source with rejection sampling and a Fisher-Yates shuffle, so every ordering of your list is equally likely — no entrant is quietly favoured by the maths. The bracket then shows every round: the opening matches (with byes marked), and the later rounds as winner-of slots, so you can print or copy the draw and fill in winners as the event runs. A text version is one click away for pasting into a chat, a doc or a scoresheet.
Everything runs in this page, on your device. The names you paste are never uploaded, sent anywhere or saved, and closing the tab clears the draw. Splitting people into groups instead of pairing them off is a different job — the Random Team Generator linked below does that — and picking a single winner without a tournament is the Random Picker.
Bracket sizes, byes and rounds at a glance
| Entrants | Bracket size | Byes | Rounds |
|---|---|---|---|
| 3–4 | 4 | 0–1 | 2 |
| 5–8 | 8 | 0–3 | 3 |
| 9–16 | 16 | 0–7 | 4 |
| 17–32 | 32 | 0–15 | 5 |
| 33–64 | 64 | 0–31 | 6 |
Seed placement for an 8-slot bracket is 1, 8, 5, 4, 3, 6, 7, 2: each opening pair sums to 9, the bracket size plus one. The same rule builds the 16, 32 and 64-slot orders.
Frequently asked questions
Is the draw really random, or can it be predicted?
The shuffle uses crypto.getRandomValues — the browser cryptographic random source — with rejection sampling and a Fisher-Yates shuffle. Every possible ordering of your entrants is equally likely, and nobody, including us, can predict or reproduce a draw after the fact. Nothing about the draw is sent to a server.
Why does seed 1 play the lowest seed first?
That is the point of seeding: the strongest entrant is rewarded with the statistically weakest opening opponent, and the top two seeds are placed so they can only meet in the final. Because this tool shuffles who receives each seed, the fairness is in the structure — the draw cannot be arranged to protect or target anyone.
What happens with an odd number of entrants, like 7 or 13?
The bracket rounds up to the next power of two (8 or 16) and the difference becomes byes: 1 bye for 7 entrants, 3 byes for 13. The byes go to the top seeds, and the remaining entrants play a short first round. From the second round on, the bracket is full and every match is played.
Can I enter the winners and advance the bracket here?
This tool produces the draw itself — the pairings and the winner-of slots for every round — rather than running the tournament. Read the winner of each match into the next round slot as results come in; the copied text version is made for exactly that, in a doc or scoresheet you control. Nothing is stored here, so a live multi-day bracket would be lost if the tab closed.
What if I type the same name twice?
Both lines count as separate entrants and both will appear in the draw, which is what you want for, say, two teams that share a name from different schools — and a mistake when it is a typo. The line under the bracket states how many entrants and byes the draw used, so check it before you announce the pairings.
Is anything I paste stored or sent anywhere?
No. The shuffle and the bracket are built in your browser tab. Nothing is uploaded, logged or kept, and refreshing or closing the page wipes the draw.
First time embedding? Read the step-by-step guide →
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