How anagram solvers work, with numbers from real word lists
Why sorting letters beats trying every arrangement, how repeated letters and blanks change the count, and which English five-letter families are largest.
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Publicerad 17 October 2026
Sort the letters, then compare
Two words are anagrams exactly when their letters are the same once sorted. "listen" sorted is eilnst. So is "silent", and so is "tinsel". That sorted string is the signature of the group.
In the English list the six-letter anagrams of "listen" are enlist, inlets, listen, silent, tinsel. A solver finds them by computing one signature and comparing it with every six-letter word.
Why not try every arrangement
Trying arrangements grows faster than any list. Six distinct letters can be ordered 720 ways, eight letters 40,320 ways and fifteen letters 1,307,674,368,000 ways (that is 15 factorial).
The list is far smaller than that. It has 8,427 six-letter words, 12,923 eight-letter words and 755 words with fifteen letters. Scanning only the words of the right length and comparing counts is why fifteen letters is as quick as five.
Repeated letters
Repeats reduce the number of different arrangements: "tease" has two e, so it has 5! / 2! = 60 distinct arrangements, not 120. A signature handles this without any special case, because the two e simply appear twice in the sorted string.
That is why "state" and "taste" are anagrams of each other but "tease" is not an anagram of either: its sorted letters are aeest, theirs are aestt.
Blanks
A ? in the scramble stands for one letter you do not know. The solver then checks that the word contains every named letter and has the right length; the remaining positions are the blanks. "aeinrst?" matches 34 eight-letter words in the English list, among them restrain, strainer and nitrates.
The biggest families
The English list has 770 groups of five-letter words that are anagrams of each other. The largest has 8 members: aster, rates, resat, stare, tares, taser, tears, treas.
Large families are why a single scramble can have several correct answers. When a puzzle needs one, use the clue that came with it to choose.