Two-List Random Matcher
Pair items from one list to another.
Built and maintained by Paul Clark, Redmoon Software · Last checked
The Two-List Random Matcher pairs each item in list A with an item from a shuffled list B. It's a quick way to hand out prizes, assign chores, set up Secret Santa, or randomly pair people with partners. Drop your two lists in, hit match, and get a clean A-to-B pairing every time.
Paste. Paste your items into list A and list B.
Click Match A → B to see a result.
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- No history yet.
How it works
- Paste. Paste your items into list A and list B.
- Match. Click Match A → B to shuffle B and pair it to A.
- Copy. Copy the resulting pairings for your records.
- Re-roll. Click Match again for a different set of pairings.
About the Two-List Random Matcher
It zips one list against a shuffle of the other
List A stays in the order you typed it. List B is shuffled, and then the two are zipped together — first of A with first of shuffled B, and so on. That produces a one-to-one matching where every pairing is equally likely, which is the correct model for assigning people to projects, partners or slots.
Because A is not shuffled, the output appears in the order you entered your people. That is a small convenience worth knowing: type your list alphabetically and the results come back alphabetically, which makes them much easier to read out.
When the lists are different lengths
If B is shorter than A, it wraps: once B is exhausted the matching starts again from the beginning of the shuffled list, so some entries in B are used more than once. If B is longer than A, the surplus entries in B are never used.
Neither case raises an error, which means a mismatch in list lengths is silent. If a one-to-one matching is what you need, check the counts first — the tool will happily give you an eight-to-five matching that looks entirely normal.
What this is and is not
This is a matching, not a series of picks. Repeatedly drawing "a random project for each person" from a picker would hand the same project to two people and leave another unassigned; zipping against a shuffle cannot. The distinction is worth understanding properly if you do this often.
Set a Seed for a matching you need to reproduce. Both lists are saved in this browser as you type.
Frequently asked questions
What happens if the lists are different lengths?
A is matched against a shuffled B. If B is shorter than A, B repeats as needed so every item in A gets a match.
Can I match a list to itself?
Yes. Paste the same list into both A and B to create random pairings within a single group.
How random is the pairing?
List B is shuffled with the Web Crypto API, giving every possible pairing an equal, unbiased chance.
Do my lists leave my device?
No. The matching runs entirely in your browser, so neither list is ever sent to a server, and it works offline.
Related randomizers
Further reading
- Three wheels give you a combination, not an assignment
The Multi-Wheel Picker spins each wheel independently, which is exactly right for "a person and a task" and exactly wrong for "everyone gets a different task". Here is what independence actually costs you, why a blank wheel disappears without a word, and how to tell which of the two jobs you have.
- Dividing things up when the numbers don't come out even
Splitting 17 items between 4 people means somebody gets a fifth one. Here is how a fair division tool deals items out at random, why it splits by count rather than value, and the one thing you should do to your list of people first.
- Who gets which prize? Let chance decide — and show your work
Picking winners is the easy half of a prize draw. The fight starts when someone has to decide who gets the good prize and who gets the mug. A random prize assigner matches people to prizes in one shuffle nobody chose.
- Secret Santa beyond December: swap formats for the whole year, and a draw you can re-run
The Secret Santa mechanic — everyone gives to exactly one person, nobody draws themselves — works just as well for book swaps, snack exchanges, and kindness weeks as it does in December. Here's a year of formats, plus how a seeded draw lets you reproduce the exact same assignment on demand.
- A chore roster that actually feels fair (and stops the arguments)
The same person always ends up on bathroom duty. Here's how a random chore roster — fresh shuffle each day, rotated across the week — spreads the jobs nobody wants without anyone keeping score, and how it handles having more chores than people.
- Matching two lists fairly: zip prizes, tasks, and partners at random
Assigning a list of people to a list of prizes, chores, or projects sounds trivial until you do it by hand and someone notices a pattern. Here's how a two-list matcher zips one list to a shuffled copy of another, what happens when the lists are different lengths, and when to reach for a different tool.