To promote children’s data protection, the design of services and products matters, as well as continued enforcement of terms of use and privacy policies by tech companies. However, the child, their rights and Privacy by Design principles place the burden on platforms to develop age-appropriate and rights-oriented experience. To highlight the duties of Big Techs and guide them in implementing children’s privacy and data protection, we present 19 legal requirements (LR) based on UNICEF’s Manifesto and the standard Children’s Right by Design. We illustrate their application by examining TikTok, one of the most popular social media platforms among children. We collected platform documentation and evidence from relevant IT news websites and large-circulation outlets to classify the compliance of TikTok practices with these LR. Our goal is to pave the way for a shift towards children’s protection and promotion by tech companies, reducing the detrimental use of their data.