Anagram Solver and Word Finder

The trick behind it

A naive solver would generate every permutation of your letters and check each one. For seven letters that is 5,040 arrangements, which is fine, but for ten it is 3.6 million and for twelve it is 479 million. That approach falls apart exactly when you need it.

The efficient method inverts the problem. Sort the letters of every dictionary word once, so "listen", "silent", "enlist" and "tinsel" all reduce to "eilnst". Sort your input the same way and a full anagram is a single lookup, no permutations required.

Finding shorter words that use only some of your letters needs a slightly different test: count how many times each letter appears in your rack, then keep any word whose own letter counts never exceed yours. That is one pass over the dictionary and it does not care how many letters you typed.

Using it for word games

The longest word is rarely the best move, which is the most common mistake in Scrabble and its relatives. A seven letter word that opens a triple word lane for your opponent loses more than the fifty point bonus gains.

What tends to matter more:

• Keep a workable rack. Aim for roughly three vowels and four consonants. Dumping all your vowels for eleven points is usually worth it if the alternative is being stuck with AEIOU next turn.
• Learn the two letter words. They are how you play parallel to an existing word and score it several times over. This is the single highest-value thing to memorise.
• Hold the blanks. A blank is worth roughly 25 points of future flexibility. Spending one to score 18 now is almost always a loss.
• Watch the premium squares you open. Before playing, look at what your word makes reachable.

Crosswords and the pattern filters

For a crossword you usually know some letters and their positions rather than a set of tiles. The starts-with and ends-with filters handle the common case, and the wildcard handles a gap in the middle.

A useful habit for cryptic clues: the wordplay often signals an anagram with words like "confused", "broken", "rearranged", "cooked", "at sea" or "out". The letters to rearrange are almost always adjacent to that signal, and the definition sits at one end of the clue.

Why the dictionary is curated

The obvious way to build a word finder is to take a large public dictionary file and use all of it. The result looks impressive and works badly.

The standard Unix word list is derived from a 1913 edition of Webster's, which is full of obsolete and technical headwords: "favism", "biga", "uncurse", "rightle". It also omits most ordinary inflections, so it contains "graving" but not "books" or "runs".

A list like that returns pages of words nobody recognises while missing the plural you were actually looking for. This one is built the other way round, from a curated set of common base words expanded with regular English morphology, and it is around 6,500 words. It will occasionally miss something valid. It will not bury the answer under nonsense.

Anagrams worth knowing

Some pairs are famous because the meaning survives the rearrangement, or comments on it. "Listen" and "silent". "Astronomer" and "moon starer". "The eyes" and "they see". "Dormitory" and "dirty room". "Funeral" and "real fun".

Anagrams were once taken seriously as a way of encoding claims. Galileo announced his observation of Saturn's rings as a Latin anagram in 1610, which let him establish priority without revealing the finding while he confirmed it. Hooke did the same with his law of elasticity. It was the seventeenth century equivalent of a timestamped hash.