The growing presence of antisemitism on social media platforms has become more prominent in recent years. Yet, while most of the scholarly attention has been focused on leading platforms like Twitter, Facebook, or Instagram, the extremist immigration to other platforms like TikTok went unnoticed. TikTok is the fastest-growing application today, attracting a huge audience of 1.2 billion active users, mostly children and teenagers. This report is based on two studies, conducted in 2020 and 2021, applying a systematic content analysis of TikTok videos, comments, and even usernames. Data were collected twice, in two four-month periods, February–May 2020 and February–May 2021, to allow for comparisons of changes and trends over time. Our findings highlighted the alarming presence of extreme antisemitic messages in video clips, songs, comments, texts, pictures, and symbols presented in TikTok’s content. TikTok’s algorithm is even more disconcerting since it leads to a spiral of hate: it pushes users who unintentionally view disturbing content to view more. Considering TikTok’s young demographic, these findings are more than alarming; TikTok even fails to apply its own Terms of Service, which do not allow content “deliberately designed to provoke or antagonize people, or are intended to harass, harm, hurt, scare, distress, embarrass or upset people or include threats of physical violence”.