Accuracy and Disclaimer

Last updated 2026-08-21.

Use the results, but check them

Puzzle Quarry is built to be accurate and is tested against known reference values. It is still software written by people, running in a browser we do not control, on input we cannot see. Treat every result as a well-informed starting point rather than an authority.

Before you rely on a result for anything that matters — money owed to someone, a legal or tax position, a medical decision, a machined part, a navigational fix — check it against a second source.

Specific limits of this site

Every puzzle published here is verified to have exactly one solution. The verification is structural rather than a test run afterwards: clues are removed from a finished grid one at a time, and a clue is only allowed to stay missing while a deduction solver can still complete the grid without it. Every cell reached that way was forced, so no second solution can exist. An independent solution counter, which knows nothing about solving techniques and simply searches, is run over generated puzzles in the test suite as a second opinion.

Every puzzle is also verified to be solvable by reasoning alone, using only the techniques described on the technique pages. This is a different property from having one solution, and it is the one most generators do not check. A grid that would have required trial and error was rejected while it was being built rather than relabelled as a harder level.

Difficulty is the hardest technique the puzzle forces you to use, not a count of its clues. That is a different measure from most binary puzzle sites and apps, so a puzzle labelled "hard" here will not necessarily match one labelled "hard" elsewhere, in either direction.

The daily puzzle is derived from the calendar date in UTC and from nothing else. It is therefore identical for every visitor, and it is also predictable: anybody can compute a future date's puzzle. No secrecy is claimed for it and none should be assumed.

Puzzles are generated in your browser using its own random number source, or from a date seed in the case of the daily. They are suitable for a newspaper page, a classroom or a waiting room. They are not certified random and must not be used where the fairness of a draw carries any weight.

Times, streaks and completion history are held in your browser's local storage and nowhere else. They are not transmitted and cannot be recovered by us. Clearing site data for this domain erases them permanently.

Not professional advice

Nothing on this site is educational or other professional advice, and using the binary puzzle generator does not create a professional relationship of any kind. If a decision has real consequences, ask somebody qualified and accountable.

Liability

Our liability for the results this site produces is limited as described in the Terms of Service. In short: the site is free, it is provided as-is, and we cannot accept responsibility for losses caused by relying on it without checking.