The global platform Substack is making money from newsletters spreading Nazi ideology, white supremacy, and antisemitism, a Guardian investigation has found. Substack has about 50 million users and takes 10% of newsletter revenue. Around 5 million people pay for content on it. One newsletter, NatSocToday, has 2,800 subscribers and charges $80 per year. It features a swastika and claims Jews caused World War II, calling Adolf Hitler “one of the greatest men of all time.” Subscribing led the Guardian to 21 similar accounts promoting hate. Erika Drexler, a National Socialist activist with 241 subscribers, calls Hitler her hero and charges $150 yearly. Ava Wolfe, with 3,000 subscribers and UK-based, uses Nazi symbols and spreads Holocaust denial, falsely claiming no one was deliberately killed during the Holocaust. Another account, Third Reich Literature Archive, has 2,100 subscribers and sells Nazi propaganda content for $80 a year. Many posts promote antisemitic conspiracy theories and deny such hate exists. Experts warn online hate content often inspires real-world violence. Danny Stone of the Antisemitism Policy Trust said hate online helped fuel attacks like the 2022 Buffalo shooting and 2018 Pittsburgh synagogue shooting. He said algorithms promoting such content are a “serious” issue. The Holocaust Educational Trust and Labour MP Joani Reid criticized Substack for profiting from Nazi and antisemitic content. Reid plans to ask regulators to act, saying online hate has deadly offline consequences. Substack’s co-founder Hamish McKenzie stated they oppose Nazis but prefer free speech over censorship. He added that their guidelines ban inciting violence. Substack did not respond to The Guardian’s request for comment. The platform faces growing pressure to remove extremist content from its site.