QuillBot

AI paraphrasing and grammar suite that grew into an all-in-one writing toolkit.

Freemium· Free tier with word limits; Premium from ~$9.95/mo (billed annually)WritingUndisclosed (proprietary)

Best for

Pick QuillBot if you want a single freemium tab for paraphrasing, grammar, and summarizing English prose, especially as a student or ESL writer.

Skip if

Skip it if you need transparent model provenance, long-form drafting, or a professional editorial workflow with team controls and audit trails.

QuillBot started life as an AI paraphraser and has expanded into a sprawling writing productivity suite covering paraphrasing, grammar checking, summarization, translation, citation generation, plagiarism detection, AI content detection, and an "AI humanizer" intended to rewrite machine-generated text into something less detectable. Around that core sit adjacent tools: an AI chat, image generator, presentation builder, document editor, PDF utilities, and browser extensions for Chrome, Word, and Google Docs.

It is squarely aimed at students, academics, ESL writers, and working professionals who want a one-stop tab for tidying up prose rather than a power-user platform like Grammarly Business or a long-form drafting tool like Sudowrite. Pricing is freemium: a generous free tier with word limits on the paraphraser and summarizer, with Premium plans unlocking unlimited length, more rewriting modes (Formal, Creative, Shorten, Expand), and faster processing. The free tier is what most people will actually use, and it is genuinely useful.

QuillBot does not disclose the underlying models, and the breadth of the suite means individual tools are competent rather than best-in-class. The AI detector and "humanizer" pair in particular sit in an arms race with detectors like GPTZero and Turnitin, and results are unreliable. For its original job, paraphrasing English prose, it remains one of the most polished tools on the market.

Editor's take

QuillBot is the default paraphraser for a reason, and the free tier alone earns it a place in any writing toolkit. The newer humanizer and AI-detector bolt-ons feel reactive and we would not trust them in a serious academic-integrity context, but the core rewriting engine remains quietly excellent.

— The AI Tool Bible editorial team

Pros

✅ Polished paraphraser with multiple rewriting modes including Formal, Creative, and Shorten
✅ Genuinely useful free tier covers the most common student and ESL workflows
✅ Deep integration via Chrome, Word, and Google Docs extensions
✅ Bundles citation, summarizer, and grammar tools so you rarely leave the tab