A free daily code-breaking game: crack an escalating chain of classic ciphers to reveal the day’s public-domain quote.
Cipherday is a free daily code-breaking game. Every day the whole world gets the same chain of three classic ciphers — a Caesar shift to warm up, a keyword substitution, then a Vigenère or rail-fence finale — hiding a short public-domain quote. Deduce each key in your browser, watch the final layer decrypt letter by letter, and earn a clean, spoiler-free card with your time and streak. No account, no cost, and the answer is never spoiled for the friend you share it with. Come back each day for a fresh puzzle, or replay past days from the archive.