Privacy and cookies

Game preferences on your device

The game uses browser local storage to remember settings such as appearance, difficulty and assistance choices. This is different from a cookie, but both are ways to store information on your device. These settings are not an account or a cloud backup.

You can remove saved preferences using your browser’s site-data controls. If preference storage is unavailable, the game uses default settings on the next visit. Your choices still work while the game remains open. Automatic saving and resuming of an unfinished game is not currently provided.

Advertising choices

Our introduction and guide pages include Google AdSense. Google and its advertising partners may use cookies, other storage and information about your visit to deliver and measure advertising, subject to applicable consent requirements. This is separate from remembering your game preferences.

Where an advertising consent message is shown, use its choices to accept, decline or manage advertising purposes. Declining advertising consent does not require you to give up Sudoku assistance settings. Browser controls that block all site storage may also prevent settings from being remembered.

Read how Google uses information from sites that use its services.

Importing puzzles

Text and CSV puzzles are processed by the game in your browser. If you choose photo import, the selected image is sent through our Cloudflare-hosted service to Nanonets for recognition. Only upload the puzzle you want converted; crop out names and other private information. You can use text or CSV instead of sending a photo.

Hosting and contact

Cloudflare hosts this website and processes requests needed to deliver it, including network information such as IP addresses. If you email us, we receive your address and the information you include so we can respond.

Helpful Sudoku is operated by Chris McGowan. For privacy questions or requests concerning information you have sent us, use our Contact us page.