Skip to content
Puzzle Quarry

The Hitori Archive

Nothing here is stored anywhere. Every past daily is built again from its own date the moment you ask for it, which is why none of these links can rot.

Puzzle #1 Hard Time 0:00 Decided 0/49

A hard 7×7 board. Tap a cell to paint it out, again to keep it, again to undo.

Check this before you rely on it. This hitori generator is provided free and without warranty, and its results are not professional advice.

Pick a day

Grown again, not fetched

A conventional archive is a directory of saved files and it fails in the ordinary ways directories fail: something gets pruned, a migration loses a month, an old link comes back holding a different board from the one somebody remembers. There are no files here. Each entry is a date, and the date is enough to rebuild the board exactly, because every choice the generator makes is driven by it.

That has a property worth naming. Rebuilding a past daily repeats the whole search — the boards that were grown and rejected for needing a guess get grown and rejected again, in the same order, and the one that survived survives again. What you are handed is not a copy of that day’s board; it is that day’s board, made the same way a second time.

The archive therefore has no edge and no upkeep. It runs back to the first daily and stops, because before that date there was no board of the day to be — not because a retention policy expired.

Days you missed, and what they are good for

Playing an old day counts as play. It goes into your history and into your best time at that size, and it does not retroactively mend a streak — a streak counts consecutive days on which you actually turned up, and repairing it afterwards would make it a record of nothing.

The archive is far more useful as a practice ground than as a list to clear. Each weekday carries a fixed difficulty, so if you want to get quick at tracing a region, work through a run of Tuesdays; if you want to drill the corner argument, take the Sundays and the Fridays. Choosing by weekday is the thing this archive can do that a folder of saved boards cannot.

Common questions

How far back does the hitori archive go?

Back to the very first daily and not a day earlier, because there was no board of the day before that. Everything since is there, made fresh from its own date each time you open it.

Will a link to an old daily board still work in a year?

It will. Nothing is stored for it to lose: the date goes into the generator and the same board comes out, this year or in ten.

Can playing old boards repair a broken streak?

It cannot. A streak is a record of days you actually turned up on, and one you could patch afterwards would be a record of nothing. The play still counts everywhere else.

More Hitori pages