Random group generator
Press Draw to see the result
Paste the register and choose how big the groups should be. The list is shuffled and dealt out evenly, so nobody is left in a group of one and the sizes never differ by more than a person.
How to make random groups
For classroom work, fixing the group size is almost always the right mode: the activity is designed for groups of three or four and the class size varies week to week. The other mode, fixing the number of groups, suits a room with a set number of tables. Random grouping is doing something specific pedagogically — it breaks up the clusters that form when students pick their own, which is usually the point of grouping them at all.
Questions
By size. The activity dictates the group size, and the class size changes.
They are spread across the existing groups rather than left in an undersized one, so sizes differ by at most one.
Yes, as often as you like. Each draw is independent.
Copy the result: nothing is stored on the site. Noting the seed lets you regenerate exactly the same groups later.
No. Every possible arrangement is equally likely.