Gab is an American alt-tech social networking service known for its far-right userbase.
Widely described as a haven for extremists including neo-Nazis, white supremacists, white nationalists, the alt-right, and QAnon conspiracy theorists, it has attracted users and groups who have been banned from other social media and users seeking alternatives to mainstream social media platforms.
Gab says it promotes free speech, individual liberty, and "the free flow of information online", though these statements have been criticized as being a shield for its alt-right and extremist ecosystem.
Antisemitism is prominent in the site's content, and the company itself has engaged in antisemitic commentary on Twitter.
Researchers note that Gab.com has been "repeatedly linked to radicalization leading to real-world violent events"

The site received extensive public scrutiny following the Pittsburgh synagogue shooting in October 2018, after it was found that the sole suspect of the attack, Robert Gregory Bowers, had posted a message on Gab indicating an immediate intent to cause harm before the shooting.
Bowers had a history of making extreme, antisemitic postings on the site.
After the shooting, Gab briefly went offline when it was dropped by its hosting provider and denied service by several payment processors.

In 2021, Gab was among the platforms used to plan the storming of the United States Capitol on January 6


https://en.wikipedia.org/wiki/Gab_(social_network)