About Zaney Sudoku

A one-person killer sudoku site, made in London, built on a simple promise: no dead ends.

Why this site exists

Too many puzzle sites serve broken killers — grids with multiple solutions, or worse, none at all — wrapped in pop-ups. Zaney Sudoku was built to fix that: every one of our 400,000 puzzles is generated deterministically and machine-verified to have exactly one solution before it's dealt. If you're stuck, the puzzle isn't broken; there's a deduction waiting.

How it works

Puzzle numbers are permanent. Hard #4,821 is the same puzzle for every person, on every device, forever — so you can share links, race friends, and come back years later. There are no accounts: your progress, streaks and stats live in your own browser, with a backup code on the stats page if you switch devices.

Who runs it

Zaney Sudoku is an independent project run from London by one person who spends an unreasonable amount of time on the rule of 45. The site is free, supported by advertising, and the guides are written by hand — including an honest one about whether sudoku is actually good for your brain.

Get in touch

Bugs, feedback, puzzle gripes, or a solve time you're proud of: contact page, or straight to deathbyleisure@gmail.com.