Copyleaks vs QuillBot

A side-by-side look at Copyleaks and QuillBot — pricing, features and where each one wins. Both are reviewed independently on Curata AI.

CopyleaksQuillBot
SummaryAI content and plagiarism detector that scans text (and images) in one unified check.AI paraphrasing, grammar and summarizing suite trusted by 50M+ students, writers and professionals.
PricingFreemiumFreemium
CategoryWritingWriting
PlatformsWebWeb, Chrome, Word, Google Docs, macOS, Edge
Key features
  • Unified AI + Plagiarism Scan (Text)
  • AI-Only Detection (Images)
  • Flat Monthly/Annual Tiers
  • Extra Credits Purchasable Anytime
  • Paraphraser (9 modes)
  • Grammar Checker
  • Summarizer
  • Citation Generator
  • AI Detector
  • AI Humanizer
  • Plagiarism Checker
  • Chrome, Word & Docs extensions
Pros
  • Confirmed flat pricing with no credit-math ambiguity (Personal $13.99/mo annual, $16.99/mo month-to-month)
  • Genuinely self-serve — instant checkout, no demo required
  • Free scan available with no signup
  • Real affiliate program: 15% recurring commission for the customer's lifetime, 30-day cookie
  • Extremely fast, focused UX built around rewriting
  • Generous free tier that's genuinely usable
  • 9 paraphrasing modes give real control over tone
  • Works inside Chrome, Word and Google Docs
  • Includes grammar, summarizer, citations and AI detector in one suite
  • Great fit for students, ESL writers and non-native English speakers
Cons
  • Word allowance is meaningfully lower on month-to-month billing (25,000 words) vs annual billing (300,000 words) at the same tier name
  • No plagiarism check for images, only AI detection
  • Not a full chatbot — no open-ended reasoning like ChatGPT
  • Free tier caps input length and locks premium modes
  • AI detector should be treated as a signal, not a verdict
  • Very long documents can require chunking

Which one should you choose?

Copyleaks

Best for: Freelance writers, editors and publishers who need to verify originality with clear, flat pricing rather than a confusing credit system.

QuillBot

Best for: AI paraphrasing, grammar and summarizing suite trusted by 50M+ students, writers and professionals.

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Read the full Copyleaks review

Copyleaks detects both AI-generated content and plagiarism in a single scan for text, plus AI-only detection for images. It's aimed at freelance writers, editors, publishers and educators who need to verify originality before delivering or accepting work, with flat, predictable monthly or annual tiers rather than a pay-as-you-go credit system.

Read the full QuillBot review

QuillBot is one of the most established AI writing assistants on the market, best known for the paraphraser that made text rewriting mainstream. Today it's a full writing suite: a paraphraser with multiple tone modes, a grammar checker, a summarizer, a citation generator, an AI detector and an AI humanizer. It integrates directly into Chrome, Microsoft Word and Google Docs, so it sits inside the tools writers already use rather than asking them to switch context. QuillBot is especially popular with students, ESL writers and content professionals who want fast, reliable rewrites without opening a general-purpose chatbot. The free tier is generous enough for casual use; QuillBot Premium unlocks unlimited paraphrasing, longer inputs, more advanced tone modes and priority processing — the plan most serious users end up on.