Google Penguin is an algorithm update launched in April 2012 that targets manipulative link-building practices. It was designed to devalue or penalise sites that had acquired links through link schemes, excessive exact-match anchor text, paid links, or low-quality link networks. Early versions ran periodically, meaning sites could be stuck with a penalty for months until the next refresh. In 2016 Penguin became a real-time, page-level signal incorporated into the core algorithm, so changes to a link profile — through disavowing spammy links or earning new quality links — take effect as Google recrawls and reprocesses the affected URLs rather than requiring a manual refresh. Penguin fundamentally shifted link-building towards quality over quantity.