Wordle Hard Mode Helper is a free Chrome extension developed by Claude Banman. It falls under the category of Browsers and the subcategory of Add-ons & Tools. This open-source extension aims to assist players in the popular word game, Wordle, by preventing the usage of letters that are known to be incorrect.

The main feature of Wordle Hard Mode Helper is its ability to keep players from playing a letter that they have already played, but is not part of the word. This can be useful in preventing accidental mistakes and improving gameplay efficiency. When a letter is typed or clicked, the extension automatically checks if that letter has already been played and marked as not in the word. If it has, the backspace key is triggered, removing the letter from the input.