What Is Quillbot? Paraphraser, Grammar Checker, AI Detector

The short answer: if most of your writing is reworking copy that already exists, Quillbot's free plan covers the Standard and Fluency paraphrasing modes and the AI Detector, and Premium adds eight more paraphrasing modes, freeze words and a Plagiarism Checker with 25,000 words a month. Premium's price is set by region and shown at checkout, so test the free tier on your own copy first.

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Before you pay for Premium:

1. Size the plagiarism allowance. For example, one 1,200-word blog post a week is 5 x 1,200 = 6,000 words in a five-week month, under a quarter of the 25,000 words in the Plagiarism Checker article. Extra word packs exist if you publish more.
2. Test on copy you already have. Run three paragraphs of your own through Standard and Fluency on the free plan, with the English variant your market reads: the language article offers American, British, Canadian and Australian English.
3. Pick a pass mark that is not a detector score. Quillbot's own detector article says detection tools are not 100% accurate and can flag human writing. Judge the rewrite on whether an editor would approve it.

What Quillbot does

The homepage calls it a suite of AI tools: the Paraphraser, Grammar Checker, AI Humanizer, Summarizer, Translate, Citation Generator and Plagiarism Checker, an AI Detector, AI Chat, and image and PDF tools, with extensions for Chrome, Edge, Safari and Word and apps for desktop and mobile. The Paraphraser is the centre. It rewrites text in ten modes, from Formal and Simple to Shorten, Expand and a Custom mode you describe in a word, and freeze words keep named terms unchanged.

Who it fits, and who it does not

It fits marketers who edit more than they draft: tightening an agency's copy, adapting one text for several channels, or helping colleagues who write in English as a second language. Team Plans group Premium seats in bands of 2 to 10, 11 to 50 and 51 or more, with a team style guide, dictionary and usage reports, per the Team Plans article.

It fits less well a team that wants to automate: Quillbot says it offers no API. Nor is it a disguise for AI drafts, since the vendor says the Paraphraser is not built to bypass detection.

What it costs

Quillbot does not publish one price. Its pricing article says Premium depends on your region and plan, offered monthly, quarterly or annually, with the local price shown at checkout on the upgrade page. That page blocked automated reading on 26 October 2026, so no figure is quoted here.

Refunds are issued only where the law requires one, per the refund article, and consumers in the EEA and UK keep a 14-day right of withdrawal after purchase. With no refund beyond what the law requires, a Premium term bought and left unused stays with Quillbot, so start on the shortest billing period the checkout offers.

How it compares

Asked whether its own tool counts as AI writing, Quillbot's help centre answers no. That is a vendor ruling on its own product, so let your school, client or editor decide what counts.

• Grammarly is the team-rules choice: Pro costs $30 per member a month or $144 a year and adds style rules and brand tones for up to 149 seats, per its pricing article, checked on 26 October 2026.
• GPTZero is detection first: 10,000 free words a month, then $23.99 a month or $12.99 billed yearly for 300,000 words, per GPTZero pricing, checked on 26 October 2026. Since September 2026 it belongs to Superhuman, Grammarly's parent, per Superhuman's announcement.

Getting started

Paste one approved paragraph, freeze the brand terms and compare two modes. How to use Quillbot runs that job through to an exported file.

FAQ

Is Quillbot free?

Mostly. The free-use article says most tools work for free, with limited daily paraphrases in the two free modes.

Does Quillbot have an API?

No. Its API article says it offers no B2B or B2C API.

Is the AI Detector paid?

No. The AI Detector is free for all users, per the detector pricing article.