QuillBot
Headquarters
Chicago, ILFounded
2017CEO / Founder
Rohan GuptaEmployees
201-500Funding
Acquired — $4.25MProducts
1 product listedAvg. AI Score
8.0/10Website
quillbot.com
Profile updated
About QuillBot
QuillBot develops AI-powered writing software, including tools for paraphrasing, grammar checking, summarizing, plagiarism detection, and citation generation. The company was founded in 2017 by Rohan Gupta, Anil Jason, and David Silin, then computer science students at the University of Illinois Urbana-Champaign, after an early version of their paraphrasing tool gained traction on Reddit. QuillBot is headquartered in Chicago, Illinois, with additional offices in Bengaluru, Berlin, and the Netherlands.
The company's flagship Paraphraser is complemented by more than 50 tools spanning grammar correction, summarization, AI detection and humanizing, translation, PDF editing, and citation generation, distributed via web, browser extensions, and mobile and desktop apps. QuillBot reports over 35 million monthly active writers and about 5.3 billion paraphraser inputs annually, with a user base weighted toward students, academics, and professional writers. Co-founder Rohan Gupta leads the business as CEO.
QuillBot raised a $4.25 million seed round led by Sierra Ventures and GSV Ventures in 2020 before being acquired by Course Hero in August 2021. Course Hero reorganized as Learneo, Inc. in 2022, and QuillBot now operates as one of Learneo's principal businesses alongside Course Hero, Scribbr, Symbolab, LitCharts, and CliffsNotes. The QuillBot unit employs roughly 225 people across its Chicago headquarters and international offices.
Specialties
Financials
Dated, source-cited figures. Estimates are marked.
Products by QuillBot
All products by QuillBot reviewed by our AI panel of experts.
Competitive Landscape
Who QuillBot competes with, and how they differ.
Grammarly is the broader grammar-and-style suite QuillBot competes with for the same student and professional writer; it leads with real-time inline correction across browsers and docs, while QuillBot leads with a dedicated Paraphraser and a cheaper premium tier.
1 product reviewed on TopReviewedWordtune, built by AI21 Labs on its own large language models, competes directly with QuillBot's Paraphraser for sentence-level rewriting, but is premium-only with far fewer free rewrites and no dedicated grammar or plagiarism suite.
2 products reviewed on TopReviewedProWritingAid targets the same individual-writer market with grammar, style, and readability reports, but centers pricing on a one-time lifetime license and deep desktop-editor integrations rather than QuillBot's freemium, web-first paraphrasing focus.
Company Timeline
Key milestones in QuillBot's history, with sources.
- Milestone
Andrew Grauer becomes QuillBot CEO as brand expands beyond writing
Under CEO Andrew Grauer, QuillBot expanded its product line beyond text with audio, image, and AI search tools, per the company's own history page.
quillbot.com - Milestone
QuillBot reaches 25 million monthly active users
Profile of CEO Rohan Gupta reports QuillBot, sold to Course Hero the prior year, reached 25 million monthly active users with a staff of 130.
chicagobusiness.com - Acquisition
Course Hero acquires QuillBot
Course Hero acquired AI-powered writing platform QuillBot, alongside study-guide brand CliffsNotes, in a deal with undisclosed terms.
publishersweekly.com - Funding
Seed round — $4M led by GSV Ventures and Sierra Ventures
QuillBot raised a $4 million seed round led by GSV Ventures and Sierra Ventures, having grown past one million users via organic Reddit traction.
builtinchicago.org - Milestone
QuillBot reaches one million users
Working out of a small Chicago office, the founders hit QuillBot's first major milestone of one million users, per the company's own history page.
quillbot.com - Founded
QuillBot founded at UIUC
Anil Jason, Rohan Gupta, and David Silin, University of Illinois Urbana-Champaign computer science students, founded QuillBot and built its Paraphraser to help English-language learners write.
quillbot.com
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