The validity of an online novel agreement depended on the specific circumstances, including the content, purpose, agreement, and implementation method of the contract. Under normal circumstances, if an online novel contract complied with the law, then it was legal. In China, the creation, publication, and adaptation of online literature involved copyright issues, so they had to abide by relevant laws and regulations. In the process of writing online novels, authors needed to sign a copyright transfer agreement to transfer their copyrights to online literature platforms or other creators. At the same time, online literature platforms also needed to sign relevant agreements to ensure that the novel content on their platforms was legal. If the content of an online novel agreement was legal, reasonable, and fair, and the parties fulfilled their obligations in the agreement, then they were legal. But if there were problems with fraud, breach of trust, unfairness, and so on, then they were illegal. Therefore, the validity of an online novel contract requires a detailed analysis of the specific situation. If you have any doubts about the validity of the contract, you are advised to consult a professional lawyer.