Hello how may I help you? What is the longest thing in the world. That's too vague of a request. Could you specify what it is that you seek? What is the longest book in the world? The longest novel in the world is A la recheerche du temps perdu by Marcel Proust. recherche* How long is it? It is an astounding 9,609+,000 characters long. 9,609,000 How many pages long is it? 4,215 Is there anything else I can help with for you today? No that's all, thank you. You're welcome.