Wordtune is developed by AI21 Labs and is powered by their proprietary large language models. It integrates into browsers via Chrome and Microsoft Edge extensions, and is available as an iOS app, enabling it to work across virtually any web-based writing surface. The platform offers context-based rewrite suggestions, a smart synonym generator, advanced grammar and spell checking, and AI continuation capabilities. For content generation, Wordtune performs multi-source fact verification (checking at least 5 sources) before surfacing factual claims, reducing hallucination risk in AI-generated copy.