QuillBot is an AI-powered writing and productivity platform designed to help students, writers, researchers, professionals, and content creators improve written communication. Its best-known tool is the Paraphraser, which rewrites text while preserving the original meaning. Users can adjust the amount of vocabulary change and choose modes for goals such as improving fluency, making text more formal, simplifying language, expanding ideas, or producing a more creative version. Free users can paraphrase limited amounts of text in two modes, while Premium unlocks unlimited paraphrasing, nine built-in modes, custom modes, comparison tools, and paraphrasing history.
The platform also includes a Grammar Checker for spelling, punctuation, and sentence-level corrections, alongside tools for proofreading, tone analysis, and improving clarity. Its Summarizer condenses articles, essays, reports, and other long materials into shorter paragraphs or key points. Translation is available across more than 40 languages, while paraphrasing itself supports multiple languages.
For academic and professional workflows, QuillBot provides a free Citation Generator supporting more than 1,000 styles, including APA, MLA, and Chicago. Its Premium Plagiarism Checker scans up to 25,000 words per month across more than 100 languages and highlights passages that may require attribution. QuillBot emphasizes that paraphrasing external material does not remove the responsibility to cite the original source.
QuillBot has expanded beyond rewriting with an AI Humanizer, AI Detector, generative writing tools, AI chat, image generation, document management, and mobile writing assistants. It is available through its website, browser extensions, Windows and macOS applications, Microsoft Word, Android, and iOS, with mobile keyboards and assistants that work across other applications.