1337x and its proxies rely on aggressive ads. In 2023, these ads often contain malicious redirects. Use (browser extension) to block pop-ups and malicious scripts.
Furthermore, in early 2023, several unofficial proxies—including specific variants of 13377x.to —were flagged for: 13377xto 2023 2021
In 2023, the official 1337x team (via their Telegram and Discord channels) issued warnings. They stated that while 13377x.to had once been a safe proxy, many copycat sites had emerged using similar URLs. They urged users to verify the official list of proxies from their .to domain. 1337x and its proxies rely on aggressive ads