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Also known as

Singles — the Same Puzzle as Hitori

If you learned it as Singles in Simon Tatham's collection, you already know how to play here.

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One genre, two names

Singles is the name Simon Tatham's Portable Puzzle Collection gave to the Japanese puzzle Nikoli published in 1990 as Hitori. The games are identical: black out cells in a numbered grid so that no number repeats among the remaining white cells of any row or column, no two black cells are orthogonally adjacent, and the white cells stay connected as a single region.

Tatham's collection made the genre familiar to a generation of desktop and Linux users, the same way newspapers spread Sudoku. Everything you know from Singles transfers here one-to-one — the sandwich and triple openings, the pair eliminations, and the connectivity endgame.

Playing Singles here

Play Hitori offers the daily-game version of Singles: one shared 5×5 board per day with streaks and shareable results, plus an unlimited collection of 600 verified-unique boards across five sizes and three graded difficulties.

Every board is guaranteed solvable by pure logic — the generator discards any puzzle that would need guessing — and the interface adds the conveniences the classic clients never had: auto-circling of proven-white cells, undo, and live highlighting of duplicates, illegal adjacencies, and cut-off regions.

Looking for the original? Play the official version here.

Frequently asked questions

Are Singles and Hitori exactly the same rules?
Yes. Shade (blacken) cells so no number repeats among unshaded cells in a row or column, no two shaded cells touch orthogonally, and unshaded cells stay connected. Only the name differs.
Why does Simon Tatham's collection call it Singles?
The collection gives puzzles descriptive English names; 'Singles' describes the goal — every surviving number is a single, the only copy in its row and column. Nikoli's original name, 'Hitori ni shite kure', makes the same joke in Japanese.
Can I play Singles puzzles online without installing anything?
Yes — every puzzle on this site runs in the browser on phone, tablet, or desktop, free and without an account.

Not affiliated with Simon Tatham's Portable Puzzle Collection. Play Hitori is an independent implementation of the public puzzle genre.

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