4-letter words starting with O

There are 157 in our dictionary. Pairing a length with a single known letter is usually enough to cut the candidate pool by more than 90%, which is why this combination is more useful than either filter alone.

Yes. Crossword grids fix the entry length before you know anything else, and Scrabble boards do the same once you spot an open lane. In both cases a length plus one confirmed letter is the normal amount of information you actually have.

Openings are where English is least predictable, so a confirmed first letter narrows the field harder than most solvers expect. Letter frequency in English is uneven enough that a common letter can return a hundred times more words than a rare one at the same length.

Yes. The filter above switches length and letter without leaving the page, and the related lists below move the same letter between first, last, and anywhere. That is usually faster than going back to the parent tool.

No. Only standard dictionary words appear, which matches what Wordle, Scrabble, and crossword grids accept. If a word you expected is missing, it is most often a name, a hyphenation, or an abbreviation.