Wordtune is an AI-powered writing and reading assistant developed by AI21 Labs that helps users rewrite, generate, and summarize text while preserving their intended meaning and tone. Launched in 2020 as AI21’s first product, it quickly gained traction as a Chrome extension and web editor that goes beyond basic grammar correction by offering context-aware paraphrasing and tone control. Since then, Wordtune has evolved into an all‑in‑one generative AI platform used by millions of users worldwide.
The product supports a range of capabilities across the writing workflow. Users can paraphrase sentences or full paragraphs, change tone between casual and formal, shorten or expand content, and generate new text from prompts. Its "Spices" feature can inject examples, counterarguments, definitions, jokes, and sourced facts directly into drafts, while a built‑in Summarizer can condense long-form text, PDFs, web pages, and YouTube videos into concise, easy‑to‑scan summaries with notes and a searchable library.
Wordtune is owned and operated by AI21 Labs, a Tel Aviv–based AI company that has raised over $600M in venture funding and builds its own large language models (Jamba and Jurassic series) rather than relying on third‑party LLMs. Wordtune runs on these proprietary models, giving AI21 tighter control over behavior, factuality, and data privacy than many competing AI writing tools. The Wordtune brand itself is positioned out of San Francisco, while AI21’s corporate headquarters and R&D remain in Israel.
In the AI writing market, Wordtune is best known as a rewriting‑first tool that combines strong paraphrasing and tone control with integrated summarization. Compared with competitors like Grammarly, Jasper, and Writesonic, it emphasizes helping users refine and express their own ideas rather than fully automating content creation. Its browser‑first experience, factual Spices feature, and focus on reliability and security inherited from AI21’s enterprise stack give it a distinct position among AI copy and content tools.