How many 4-letter words are there?
There is no single number, because every dictionary draws the line in a different place. This list holds 1,855 common four-letter words taken from the everyday-vocabulary word bank WordleSolver uses across the site. The Official Scrabble Players Dictionary (Sixth Edition) accepts about 3,996 four-letter words, and combined Scrabble and Words With Friends lists reach roughly 5,880.
The gap is mostly rare, archaic and technical forms such as AAHS, which game dictionaries accept but few people ever write. For reading, teaching or a casual puzzle, the shorter list is faster to scan. To check whether a play is legal in Scrabble, use that game's official dictionary instead.