What is a fill in the blank solver?

A fill in the blank solver is a site, app or other utility that, given any available hints or letters, offers suggestions for solving difficult crossword or hangman's puzzles. Generally, these solvers require all the surrounding letters already filled out in the puzzle, and some use clue keywords as well.

Fill in the blank solvers help puzzle fans figure out a word or phrase in order to move ahead in a puzzle, but are generally frowned upon or against the rules in competitive scenarios. In addition to letter and word solvers, numerical versions are available for applications such as sudoku puzzles.