# QuillBot

> Source: https://aiwiki.ai/wiki/quillbot
> Updated: 2026-06-10
> Categories: AI Companies, AI Tools & Products, Natural Language Processing
> From AI Wiki (https://aiwiki.ai), a free encyclopedia of artificial intelligence. Quote with attribution.

## Introduction

QuillBot is an [artificial intelligence](/wiki/ai)-powered writing platform that provides paraphrasing, grammar checking, summarization, plagiarism detection, citation generation, translation, and AI content detection tools. Founded in 2017 by three computer science students at the University of Illinois at Urbana-Champaign (UIUC), the platform grew from a single [paraphrasing](/wiki/paraphrasing) tool into a comprehensive writing assistant used by tens of millions of registered users worldwide.[1] QuillBot was acquired by Course Hero (later renamed [Learneo](/wiki/learneo)) in August 2021[4] and operates as part of Learneo's portfolio of learning and productivity brands, which by 2024 had expanded to include CliffsNotes, Course Hero, LitCharts, Scribbr, Symbolab, LanguageTool, and Bartleby.[22]

QuillBot is headquartered in Chicago, Illinois, at 303 East Wacker Drive, Suite 2101. The product is offered as a web application at quillbot.com, a Chrome extension with more than 6 million users[23], a free Microsoft Word add-in[24], and dedicated apps for macOS, Windows, iOS, and Android. In May 2026 the company rebranded around the tagline "Write, Design & Create," repositioning QuillBot as a creativity platform whose tools also span image generation, design templates, presentations, and PDF workflows.[33][39]

## History

### Founding and Early Development (2017-2019)

QuillBot was co-founded in 2017 by Rohan Gupta, Anil Jason, and David Silin.[1] The three founders met as computer science students at UIUC. Anil Jason and David Silin had previously collaborated on several hackathons together, winning 11 consecutive hackathon competitions. Anil Jason and Rohan Gupta connected through UIUC's iVenture Accelerator program.

The original motivation for building QuillBot came from Anil Jason, who wanted to create a tool that could help English Language Learner (ELL) students improve their writing. After recruiting Gupta and Silin, the team built the first version of QuillBot's paraphraser. Rohan Gupta serves as CEO[20], Anil Jason as CTO, and David Silin as CSO.

Shortly after launch, QuillBot went viral on Reddit, attracting a rapid influx of early users.[2] The founders then entered UIUC's iVenture Accelerator[1], where they won initial funding to continue developing the platform. During this period, the company operated on a bootstrapped basis, reinvesting revenue to grow the product.[2]

### Seed Funding and Growth (2020)

In April 2020, QuillBot closed a $4.25 million seed funding round led by Sierra Ventures and GSV Ventures, with participation from Service Provider Capital, AI Venture Labs, and TBD Ventures.[7] Prior to this round, the company had been entirely bootstrapped by its founders.[2] The seed funding allowed the team to expand its engineering workforce and accelerate feature development beyond the original paraphrasing tool.

By 2020, QuillBot had already begun experiencing significant user growth, driven in part by the shift to remote learning during the COVID-19 pandemic. Students and professionals increasingly turned to online writing tools, and QuillBot benefited from this broader trend.

### Acquisition by Course Hero (2021)

On August 19, 2021, Course Hero announced the acquisition of QuillBot.[4] The financial terms of the deal were not publicly disclosed. At the time of the acquisition, QuillBot had raised a total of approximately $4.34 million across its funding rounds[17] and had already amassed millions of active users.

The acquisition placed QuillBot alongside other Course Hero properties, including CliffsNotes and LitCharts. Following the acquisition, Course Hero raised a $380 million Series C round in December 2021 at a $3.6 billion valuation, led by Wellington Management with participation from Sequoia Capital Global Equities, OMERS Growth Equity, and D1 Capital Partners.

### Rebranding to Learneo (2022-2023)

In December 2022, Course Hero co-founder Andrew Grauer announced the creation of a new parent company called Learneo, Inc.[5][6] The rebranding was made public in May 2023. The move reflected the company's expansion from a single educational platform into a portfolio of distinct business units. As of 2023, Learneo's portfolio included Course Hero, QuillBot, CliffsNotes, LitCharts, Scribbr, and Symbolab. Learneo later acquired LanguageTool in March 2023 to further strengthen its AI writing capabilities[13], and in May 2023 it acquired the Digital Student Solutions (DSS) segment of Barnes & Noble Education, which added Bartleby and Student Brands to the portfolio.[21] By 2024, Learneo described itself as operating eight brands, served more than 100 million monthly active users across the group, and reported combined revenue exceeding $200 million.[22]

Rohan Gupta continued to lead QuillBot as its CEO under the Learneo umbrella.[20]

### Product Expansion (2024-2026)

Following the rebranding, QuillBot moved aggressively beyond its original paraphraser into a broad suite of free AI writing utilities. New capabilities released in 2023 through 2025 included an AI-augmented translator with explanations of grammar and word choice[44], a refreshed AI detector capable of distinguishing fully AI-written, AI-refined, and human-authored text[18], and an expanded library of standalone generators (cover letters, business plans, character descriptions, product launch copy, and more) hosted on the quillbot.com/ai-writing-tools hub.[26]

In August 2025, QuillBot launched a Team Style Guide feature for its Teams plan, allowing organizations to define and enforce a shared tone, vocabulary, and formatting rules across users.[37] In October 2025 the company added a tenth paraphrasing mode informally branded "Boomer Mode," which converts Gen Z and internet slang into more conventional professional language[36], and rolled out an AI Character Generator[34] and a Speech to Text feature. The same month, QuillBot adjusted its pricing for the first time in years, raising the headline annual plan to $99.95 per year (an effective $8.33 per month) and the standalone monthly plan to $19.95.[25]

In November 2025, QuillBot updated its privacy policy to begin storing text inputs from desktop users in order to personalize results and train future models, with opt-out controls available in account settings.[38] The change drew criticism from some academic and privacy commentators, particularly those handling sensitive student or client work, and is one of several flashpoints in the broader debate over how AI writing tools should treat user content.

### Expansion into Design Tools and 2026 Rebrand

In August 2025, QuillBot introduced AI Chat, a [chatbot](/wiki/chatbot)-style assistant built into the platform for brainstorming, drafting, and proofreading without switching tools; the company announced the feature on August 12, 2025.[35] On October 11, 2025, QuillBot expanded beyond text for the first time with a set of AI image tools, including an AI Image Generator, a Background Remover, an Image to Text [optical character recognition](/wiki/optical_character_recognition) converter, an AI Logo Generator, an AI Tattoo Generator, an AI Art Generator, an AI Background Generator, and the AI Character Generator.[34][40]

By mid-2026 the platform had added further creation utilities: an AI Presentation Maker that generates slide decks from a prompt,[42] a PDF suite covering ChatPDF-style document question answering, PDF editing, and merge, split, and format-conversion tools,[39] and a free AI Image Detector that assigns an authenticity score to uploaded images and flags AI-enhanced regions, [deepfake](/wiki/deepfake)-style artifacts, and AI-based face swaps.[41]

On May 29, 2026, QuillBot unveiled a company-wide rebrand under the tagline "Write, Design & Create," describing itself as "a creativity platform that helps you do things you don't know how to do." The redesign introduced a bolder logo with variations for different tools, a custom typeface named Quill Sans, a brighter color palette, more human-centered imagery, and updates to AI Chat and the Background Remover.[33]

## Technology

### Core Architecture

QuillBot's tools are built on [natural language processing](/wiki/natural_language_processing) (NLP) techniques and [deep learning](/wiki/deep_learning) algorithms. At the core of the platform are [transformer](/wiki/transformer)-based language models, similar in architecture to models in the [GPT](/wiki/gpt) family, that analyze the semantics and context of input text before generating alternative phrasings or corrections.[15]

The system processes text through several stages:

1. **Semantic analysis:** The AI breaks down the input text to understand intent, key ideas, and contextual meaning.
2. **Rephrasing or correction:** Depending on the tool being used, the model proposes alternate phrasings, identifies grammatical errors, or generates summaries. For paraphrasing, the system uses techniques such as synonym substitution, syntactic restructuring, and sentence reordering.
3. **Ranking and selection:** Proposed outputs are ranked by fluency, diversity, and adherence to the selected mode or style, with rules applied for grammar and register.
4. **Meaning preservation:** The algorithms prioritize retaining the original meaning of the text, avoiding information loss during rephrasing.

### Training Data and Fine-Tuning

QuillBot's models are trained on large datasets covering grammar, spelling, punctuation, tone, sentence structure, and clarity. The company has stated that its language models are "carefully fine-tuned on human-curated internal data, and interwoven with additional components" beyond standard [pre-training](/wiki/pre-training) on public text corpora. This fine-tuning process allows the models to handle different writing styles and tones across the platform's various modes.

### Knowledge Distillation

QuillBot's engineering team has published research on compressing large language generation models using sequence-level [knowledge distillation](/wiki/knowledge_distillation).[11] The work, authored by Brendan Chambers and David Silin together with collaborator Kevin Gimpel of the Toyota Technological Institute at Chicago, addresses the practical problem that billion-parameter models impose heavy hardware, energy, and latency costs at production scale. By training smaller "student" models to replicate the behavior of much larger "teacher" models, QuillBot can deliver real-time paraphrasing and grammar suggestions without sacrificing output quality, and at a unit cost low enough to support a generous free tier.

### Infrastructure

QuillBot runs on [Google Cloud](/wiki/google_cloud_terms) infrastructure. According to a Google Cloud case study, QuillBot has scaled its infrastructure up to 100 times its original capacity to handle growing user demand, processing over 100 million paraphrasing queries per month.[8] The platform relies heavily on GPU-backed inference clusters, with smaller distilled models handling the bulk of free-tier traffic and larger models reserved for premium modes such as Academic, Formal, and the AI Humanizer.

### Shared Technology Across Learneo

Since the Learneo restructuring, QuillBot's NLP stack has been deployed inside several sibling brands. The free paraphrasing tool on Scribbr.com is powered by QuillBot's models, and Scribbr's AI Detector is, according to both companies, a wrapper around QuillBot's underlying detector.[27] This sharing arrangement lets Learneo invest in a single AI research group while reaching audiences with very different brand identities (academic editing on Scribbr, multilingual proofreading on LanguageTool, and student writing assistance on QuillBot).

## Features

### Paraphraser

The paraphraser is QuillBot's flagship tool and the product that launched the company. It rewrites input text while preserving the original meaning, offering users multiple ways to express the same idea. The tool is free to use with no account required, and there is no limit on the number of paraphrases a user can run.

As of 2026 the paraphraser exposes ten predefined modes plus unlimited custom modes for premium subscribers:

| Mode | Description | Availability |
|------|-------------|-------------|
| Standard | Replaces words with synonyms and rearranges word order while maintaining meaning | Free |
| Fluency | Improves clarity and readability of the text | Free |
| Formal | Rewrites text in a professional tone suitable for workplace or academic contexts | Premium |
| Academic | Adjusts text for a scholarly or research-focused tone | Premium |
| Simple | Simplifies complex language for general audiences | Premium |
| Creative | Allows greater deviation from the source text for more varied output | Premium |
| Expand | Elaborates on the text, adding more detail and length | Premium |
| Shorten | Condenses the text while retaining key information | Premium |
| Boomer | Converts Gen Z and internet slang into conventional professional language (added October 2025)[36] | Premium |
| Custom | User-defined modes with configurable parameters | Premium |

A "Synonym Slider" control lets users adjust the degree of change applied to the text.[14] Moving the slider to the left produces a more conservative rephrase with fewer word changes; moving it to the right generates a more creative output with more extensive modifications.

### Grammar Checker

QuillBot's grammar checker identifies and corrects errors in spelling, grammar, punctuation, and sentence structure. The tool uses [AI](/wiki/ai)-powered analysis to provide inline suggestions, highlighting errors directly in the text and offering one-click fixes. The grammar checker is available for free on QuillBot's website and through its browser extensions, and it is one of the features QuillBot most directly markets as a competitor to [Grammarly](/wiki/grammarly).

### Plagiarism Checker

The plagiarism checker uses [machine learning](/wiki/machine_learning) algorithms to compare submitted text against a database of published works, web pages, and academic papers. The tool analyzes both the wording and the semantic content of the text to detect potential instances of unattributed borrowing. Results include a percentage score and highlighted passages that match existing sources. The plagiarism checker is a premium feature with a limited number of free scans available, and is distinct from the Turnitin-backed plagiarism check offered by sister brand Scribbr.

### Summarizer

The summarizer condenses long documents, articles, or papers into shorter versions while retaining the critical information and core message. Users can adjust the summary length and choose between a "Key Sentences" mode (which extracts the most important sentences from the original text) and a "Paragraph" mode (which generates a new condensed paragraph).

### Citation Generator

QuillBot's citation generator creates formatted citations in APA, MLA, and Chicago style. Users can generate both full bibliographic citations and in-text citations. The tool supports citations for books, journal articles, websites, and other source types. As of early 2024, the citation generator had processed over 12 million citation checks.[9]

### Translator

The translator supports over 50 languages, allowing users to translate text between language pairs. The tool uses AI-based [machine translation](/wiki/machine_translation) and is integrated into the broader QuillBot platform, so users can translate text and then immediately paraphrase or grammar-check the output. The tool launched on March 14, 2023 with support for more than 30 languages, and its announcement highlighted explanatory annotations covering sentence structure, word choice, and verb conjugation, positioning the translator as a learning tool for ESL students rather than a pure machine-translation service.[44]

### AI Detector

QuillBot's AI content detector analyzes text to estimate the likelihood that it was written by a human or generated by an AI system such as [ChatGPT](/wiki/chatgpt), [GPT-4](/wiki/gpt4), or [Gemini](/wiki/gemini). The detector classifies each section of text into one of four categories: AI-generated, AI-generated and AI-refined, human-written and AI-refined, or human-written.[18] It also supports bulk document uploads and is targeted explicitly at GPT-5- and Gemini-class outputs in QuillBot's marketing.[18]

Independent benchmarks of the detector have produced a wide range of results, depending on the type and length of input.[28] Reported accuracy figures include roughly 64% on machine-generated content in one 2025 audit, 78 to 91% across other 2025 reviews, and 92 to 98% on raw, unedited AI text in a separate test set. Reviewers consistently note two limitations: accuracy drops sharply once AI text has been paraphrased or hand-edited, and the detector exhibits a non-trivial false-positive rate on human writing (one test reported around 35%). For comparison, GPTZero and Turnitin have reported above-90% detection rates on similar benchmarks. These caveats have led most academic guidance to treat any AI-detector verdict as a signal for further investigation rather than as proof of misconduct.

QuillBot also offers a companion AI Image Detector, a free tool that applies similar analysis to images and reports an authenticity score along with signs of AI generation or manipulation.[41]

### AI Humanizer

The AI humanizer tool transforms AI-generated text into more natural, human-sounding language by adjusting tone, clarity, and flow without changing the underlying meaning. The humanizer supports multiple languages, including Spanish, German, French, and Portuguese, as well as four English dialects (US, UK, Australian, and Canadian). A basic version is available for free, with an advanced mode available to premium subscribers. The humanizer is a controversial feature: while QuillBot positions it as a way to soften the stiff, formulaic register of [large language model](/wiki/large_language_model) output, it is also widely used as an explicit AI-detector evasion tool and has drawn criticism from educators and from competing detection vendors.

### QuillBot Flow

QuillBot Flow (formerly known as Co-Writer) is an integrated writing workspace that combines research, note-taking, citation generation, paraphrasing, grammar checking, and AI-powered text suggestions into a single environment.[19] Key features include:

- **Complete Paragraph:** Analyzes existing text and generates three unique continuation options that match the user's writing style and context.
- **Collaborative editing:** Multiple users can work together on the same document in real time.
- **AI Review:** Provides comprehensive content analysis and improvement suggestions.
- **Note-taking and bookmarking:** Allows users to organize research materials and bookmark important sources within the writing workspace.

Flow is designed for students, researchers, and content creators who want to write, research, and edit without switching between multiple applications.

### Free AI Writing Tools Hub

In parallel with its core suite, QuillBot operates a collection of free, single-purpose generators at quillbot.com/ai-writing-tools. The hub includes a cover letter generator, an AI business plan generator, an AI character generator (added October 2025), a product launch copy generator, an essay outline generator, an email writer, and dozens of similar utilities.[26] Most run without a sign-up. The hub serves both as an SEO funnel for QuillBot's premium subscriptions and as a way for the company to test specialized prompts before promoting them into the main product.

## Integrations and Platform Availability

QuillBot is available through several platforms and integrations:

| Platform | Description |
|----------|-------------|
| Web application | Full suite of tools available at quillbot.com |
| Chrome extension | Provides grammar checking and paraphrasing on Gmail, Google Docs, LinkedIn, Outlook, Slack, Confluence, Notion, Facebook, X (formerly Twitter), and other websites |
| Microsoft Word add-in | Free add-in (available via the Microsoft AppSource marketplace) that integrates the paraphraser and grammar checker as a sidebar within Word for Windows, Mac, and Word on the web |
| macOS app | Desktop application for Mac users with system-wide pop-up integration |
| Windows app | Desktop application that surfaces QuillBot inside Slack, Outlook, and other Windows apps |
| iOS app | Mobile writing assistant and keyboard app for iPhone and iPad |
| Android app | Native Android app providing paraphrasing and grammar checking on mobile |
| Edge extension | Extension for Microsoft Edge offering QuillBot's writing tools in the Edge browser[39] |
| Safari extension | Extension for Apple's Safari browser, listed among QuillBot's apps as of 2026[39] |

According to QuillBot's listing on the Chrome Web Store, the Chrome extension has been installed by more than 6 million users as of 2025, up from roughly 2 million users at the time of the Course Hero acquisition.[23] The extension works across most websites and activates as a floating widget that appears alongside text input fields.

As of June 2026, the Chrome listing, by then renamed "Quillbot: AI Writing Assistant to Grammar Check, Paraphrase & Translate," carried the Chrome Web Store's Featured badge and a 4.7 out of 5 user rating.[23]

## Pricing

QuillBot operates on a freemium model. Following an October 2025 price adjustment, the headline tiers are:

| Plan | Price | Key Features |
|------|-------|--------------|
| Free | $0 | Paraphraser (Standard and Fluency modes), grammar checker, summarizer (limited), translator, basic AI humanizer |
| Premium (monthly) | $19.95/month | All paraphrasing modes, unlimited custom modes, plagiarism checker, advanced AI humanizer, priority processing |
| Premium (semi-annual) | ~$6.66/month ($39.95 every 6 months) | Same Premium feature set, billed twice a year |
| Premium (annual) | $8.33/month ($99.95/year) | Same Premium feature set, billed once a year |
| Student | $6.25/month (annual, requires .edu email) | All Premium features at a student discount |
| Teams | $7.50/user/month (2-10 seats, billed annually) | All Premium features plus Team Style Guide, centralized billing, and admin controls; volume discounts available for 11+ seats |

All paid plans include a 3-day money-back guarantee.[25] Approximately 60% of QuillBot's subscription revenue comes from annual plan subscribers.[9] The 2025 price increase, in which the headline annual plan rose from roughly $49.95 per year to $99.95 per year and the monthly plan from $9.95 to $19.95, was the largest pricing change in the company's history and was applied gradually to existing customers via grandfathered renewals.

## User Base and Market Position

User-count claims for QuillBot vary widely across sources and time periods. The company stated in 2022 that more than 150 million people had used QuillBot at least once, while early-2024 disclosures cited 75 million registered users worldwide spread across more than 190 countries.[9] The platform attracts roughly 25 million monthly active users[9] and processes over 100 million paraphrasing queries per month.[8] The discrepancy between the 150 million and 75 million figures appears to reflect different methodologies (cumulative visitors versus registered accounts) rather than a decline in user base.

Key user demographics reported by QuillBot and third-party analytics providers include:

- Approximately 70% of users are students or academics.[9]
- About 35% of users are based in the United States, with India representing roughly 18% of traffic[9] and Germany and the Philippines also among the top countries.
- Over 60% of users access the platform through mobile devices.[9]
- Around 8 million students use the platform on a monthly basis.
- QuillBot is recommended by more than 200 universities.[9]
- About 25% of users are paid subscribers.[9]

QuillBot holds an estimated 18% market share in the AI writing tools sector[9] and ranks as the second-largest paraphrasing tool globally by user base. The platform has a 4.7 out of 5 rating on Trustpilot.[9]

Company-reported figures continued to climb after the acquisition. A March 2023 press release stated that QuillBot had grown from 10 million monthly users in 2022 to more than 30 million monthly users at the time of its translator launch.[44] By mid-2026, QuillBot's own site cited more than 35 million monthly active writers, 5.3 billion paraphraser inputs per year, users in more than 180 countries, and more than 140 partner institutions.[1][39] An Amplitude case study of the company's signup-flow redesign likewise described a base of more than 35 million monthly users and reported that the redesign raised signup rates by 30%.[10]

## Competition

QuillBot competes with several other [AI writing](/wiki/AI_writing) tools, each with a different primary focus:

| Competitor | Primary Focus | Key Differentiator |
|------------|---------------|--------------------|
| [Grammarly](/wiki/grammarly) | Grammar, spelling, and style checking | Comprehensive proofreading with tone detection and style guides |
| [Wordtune](/wiki/wordtune) | Sentence-level rewriting and tone adjustment | Focuses on enhancing existing writing rather than catching errors |
| ProWritingAid | Long-form writing analysis | In-depth reports on writing style, readability, and consistency |
| [Jasper AI](/wiki/jasper_ai) | AI content generation | Designed for marketing teams and long-form content creation |
| Spinbot | Quick bulk text spinning | Minimal interface for fast, no-frills paraphrasing |
| LanguageTool | Multilingual grammar checking | Supports over 30 languages; now a Learneo sibling brand |
| GPTZero | AI content detection | Specialized detector frequently cited as a benchmark for QuillBot's own AI Detector |

Compared to [Grammarly](/wiki/grammarly), QuillBot offers lower pricing for premium plans and more robust paraphrasing capabilities with its ten-mode system. Grammarly, by contrast, provides stronger grammar and style checking features, tone detection, and a larger integration ecosystem. Many writers use both tools for complementary purposes. Within Learneo, QuillBot also overlaps with LanguageTool (for grammar) and Scribbr (for academic editing), but the parent company has positioned each brand at a different point on the price/specialization curve rather than treating them as direct rivals.

## Academic Integrity Concerns

QuillBot's paraphrasing capabilities have raised questions about academic integrity, particularly in educational settings. The central concern is that students may use the tool to rephrase copied content in order to bypass plagiarism detection software such as Turnitin.

Some educators have identified a practice called "patchwriting," in which students combine paraphrased snippets from multiple sources into what appears to be original text. While the wording changes, the underlying ideas remain unattributed, which constitutes plagiarism under most academic honor codes.

Institutional responses have varied. Universities such as Harvard and Stanford have updated their honor codes to address AI tool usage, generally allowing tools like QuillBot for drafting purposes but requiring disclosure when submitting final work. Other institutions have taken stricter positions: some consider text altered through paraphrasing software to be a form of academic misconduct, with penalties including course failure.

The arrival of generative-AI detectors has added a second layer to the debate. Tools such as [Turnitin](/wiki/turnitin), [GPTZero](/wiki/gptzero), and QuillBot's own AI Detector now flag suspected machine-generated text, while QuillBot's AI Humanizer is openly marketed (and widely used) as a way to make AI output less detectable. This has produced a continuous "arms race" between detectors and humanizers, with each side updating models in response to the other. Researchers studying the dynamic have warned that reliance on automated detectors carries a meaningful risk of false accusations, particularly against non-native English writers, and most institutional policy bodies now recommend pairing any detector verdict with human review and student dialogue.

Peer-reviewed research has quantified the evasion effect. A 2023 study in the International Journal for Educational Integrity tested 14 detection systems, 12 publicly available tools plus the commercial services Turnitin and PlagiarismCheck, against ChatGPT-generated essays, including a test set that had been machine-paraphrased with QuillBot in its default Standard mode. The authors found that the tools were biased toward classifying text as human-written, that obfuscation through paraphrasing significantly worsened detection performance, and that the systems tested were "neither accurate nor reliable" at identifying AI-generated text.[43]

QuillBot's own help center addresses the question directly, stating that the tool is designed to help users improve their writing skills rather than to facilitate cheating.[16] The company positions QuillBot as a learning aid comparable to a thesaurus or style guide, arguing that its proper use involves understanding and engaging with the content being paraphrased.

## Privacy and Data Use

For most of its history QuillBot processed text inputs on the fly without retaining them. In November 2025 the company updated its privacy policy and product behavior so that text submitted from desktop clients (web, Word add-in, and desktop apps) is now stored on QuillBot servers and may be used to personalize results and to train future models.[38] Users can opt out of training use in account settings, and Teams plan administrators retain organization-level controls. QuillBot's help center describes the November 8, 2025 update as replacing the earlier consent prompt with two separate opt-out controls, one for storing text inputs and one for using them to train the models behind its AI tools, with storage enabled by default for extension users; inputs from Team plan users remain excluded from model training by default.[38] The change brought QuillBot into closer alignment with how most other major AI writing tools handle user content but drew pushback from some academic and legal users, who treat client text as confidential. QuillBot also publishes a Trust Center page covering encryption in transit and at rest, role-based access controls, and SOC 2 audit status.[45]

## Reception

Reviewers generally describe QuillBot as the most polished and accessible paraphrasing tool on the market, with particular praise for the multi-mode paraphraser, the synonym slider, and the breadth of the free tier. The Chrome extension is consistently rated as one of the best free writing utilities for use inside Gmail, Google Docs, and LinkedIn. Critics, on the other hand, point to several recurring weaknesses: the AI Detector's variable accuracy, the AI Humanizer's mixed reliability, the inability to generate original long-form content from a brief or keyword (a gap that competitors such as [Jasper AI](/wiki/jasper_ai) fill), and the price increases introduced in late 2025. Capterra and G2 user ratings sit in the 4.4 to 4.6 range out of 5, and Trustpilot ratings hover near 4.7 out of 5.

## See Also

- [Grammarly](/wiki/grammarly)
- [Natural Language Processing](/wiki/natural_language_processing)
- [AI Writing](/wiki/AI_writing)
- [Jasper AI](/wiki/jasper_ai)
- [Wordtune](/wiki/wordtune)
- [Transformer](/wiki/transformer)
- [ChatGPT](/wiki/chatgpt)
- [Paraphrasing](/wiki/paraphrasing)
- [Knowledge Distillation](/wiki/knowledge_distillation)
- [Learneo](/wiki/learneo)

## References

1. "About QuillBot." QuillBot. https://quillbot.com/about
2. "How Rohan Gupta Co-Founder And CEO Of QuillBot Raised $4.25M To Make Writing Painless." Asia Tech Daily. https://asiatechdaily.com/rohan-gupta-co-founder-ceo-quillbot/
3. "Interview with Rohan Gupta, co-founder of QuillBot." Ness Labs. https://nesslabs.com/quillbot-featured-tool
4. "Course Hero Acquires CliffsNotes, Quillbot." Publishers Weekly. https://www.publishersweekly.com/pw/newsbrief/index.html?record=3373
5. "Introducing Learneo." Andrew Grauer, Medium. https://andrewgrauer.medium.com/introducing-learneo-a38b2003fccc
6. "Course Hero Appoints New CEO; Co-Founder Becomes CEO of New Parent Company, Learneo." PR Newswire. https://www.prnewswire.com/news-releases/course-hero-appoints-new-ceo-co-founder-becomes-ceo-of-new-parent-company-learneo-301702615.html
7. "QuillBot Raises Over $4M in Seed Funding." FinSMEs. https://www.finsmes.com/2020/04/quillbot-raises-over-4m-in-seed-funding.html
8. "QuillBot scales up to 100X with Google Cloud." Google Cloud Blog. https://cloud.google.com/blog/topics/customers/quillbot-scales-up-to-100x-with-google-cloud
9. "QuillBot Statistics: Adoption, Usage, & Performance Trends." SEO Sandwitch. https://seosandwitch.com/quillbot-statistics/
10. "QuillBot's User-First, Data-Driven Approach Boosts Signups by 30%." Amplitude Blog. https://amplitude.com/blog/quillbot-optimized-signup-rates
11. "Compressing Large Language Generation Models with Sequence-Level Knowledge Distillation." QuillBot Blog. https://quillbot.com/blog/quillbot-tools/compressing-large-language-generation-models-with-sequence-level-knowledge-distillation/
12. "This AI startup aims to be a one-stop writing platform." YourStory. https://yourstory.com/2021/07/chicago-jaipur-ai-startup-quillbot-one-stop-writing-platform
13. "Learneo, Inc. Accelerates AI Writing Innovation with LanguageTool Acquisition." PR Newswire. https://www.prnewswire.com/news-releases/learneo-inc-accelerates-ai-writing-innovation-with-languagetool-acquisition-301790381.html
14. "What are modes in the QuillBot Paraphraser and how do I use them?" QuillBot Help Center. https://help.quillbot.com/hc/en-us/articles/35854318883351
15. "How Does QuillBot Work?" QuillBot Blog. https://quillbot.com/blog/quillbot-tools/how-does-quillbot-work/
16. "Is using QuillBot cheating?" QuillBot Help Center. https://help.quillbot.com/hc/en-us/articles/4405594422935-Is-using-QuillBot-cheating
17. "QuillBot - Crunchbase Company Profile & Funding." Crunchbase. https://www.crunchbase.com/organization/quillbot
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