Introduction
When it comes to writing tools, Grammarly is a household name. Millions trust the Grammarly check for catching typos, fixing grammar mistakes, and improving writing clarity. But many users don't realize that Grammarly's strength lies in grammar—not plagiarism detection. The Grammarly plagiarism checker is actually a secondary feature that comes with significant limitations.
Red Paper, on the other hand, is purpose-built for plagiarism and AI detection. While we also offer grammar checking, our core focus is helping users verify content originality with industry-leading 99% accuracy. So which tool should you choose in 2026?
In this comprehensive comparison, we'll examine the Grammarly plagiarism detector against Red Paper across detection accuracy, AI checking capabilities, grammar features, pricing, and overall value. By the end, you'll know exactly which plagiarism checker fits your needs at www.checkplagiarism.ai.
Grammarly Plagiarism Checker: What It Offers
Grammarly launched as a grammar checker free tool and evolved into a comprehensive writing assistant. The plagiarism checker was added later as a Premium feature. Here's what the Grammarly plagiarism checker actually provides:
📊 Database Coverage
Grammarly's plagiarism detector scans against ProQuest academic databases and billions of web pages. However, it doesn't access as many sources as dedicated plagiarism tools. The database is solid but not comprehensive compared to specialized services.
📝 Integration with Writing
One advantage of Grammarly check is seamless integration. You can check grammar and plagiarism in the same interface. The tool highlights potentially plagiarized passages alongside grammar suggestions, creating a unified editing experience.
💻 Platform Availability
Grammarly works across browsers, desktop apps, Microsoft Office, and Google Docs. This broad integration makes the grammar and plagiarism checker convenient for users who write across multiple platforms.
⚠️ Premium Only
Here's the catch: Grammarly plagiarism checker free doesn't exist. Plagiarism detection requires Grammarly Premium, which costs $12-30/month. The free version only offers basic grammar checking—no plagiarism features whatsoever.
Grammarly's Plagiarism Detection Limitations
While Grammarly plagiarism detector serves casual users adequately, it has notable limitations that matter for academic and professional use. Understanding these gaps helps explain why dedicated plagiarism detection tools exist.
❌ No AI Detection
This is Grammarly's biggest gap in 2026. With ChatGPT and AI writing tools everywhere, detecting AI-generated content is essential. Grammarly offers zero AI detection capabilities. You can check grammar and basic plagiarism, but AI content passes through completely undetected.
❌ Limited Source Database
Grammarly scans ProQuest databases and web content, but its coverage doesn't match dedicated plagiarism checkers like Turnitin or Red Paper. Academic journals, international publications, and niche databases may not be fully indexed, leading to missed matches.
❌ Basic Similarity Reports
The Grammarly plagiarism report shows matched passages but lacks the detailed source analysis that academic users need. You see that something matches, but investigating the original source requires extra steps compared to dedicated tools.
❌ No Paraphrase Detection Strength
Detecting paraphrased plagiarism requires sophisticated semantic analysis. Grammarly's plagiarism detector grammarly primarily catches direct copying. Cleverly reworded content often slips through, creating false confidence in originality.
❌ Premium Price for Secondary Feature
Paying $12-30/month primarily for grammar checking means plagiarism detection comes at a premium. Users who need serious plagiarism verification but don't need advanced grammar features pay for capabilities they won't use.
Red Paper: Purpose-Built Plagiarism Detection
Red Paper approaches content verification differently. While we include grammar checking, our core mission is delivering the best plagiarism checker and AI detection available. Here's what sets us apart from the Grammarly plagiarism checker.
✅ 99% Detection Accuracy
Red Paper achieves 99% accuracy in plagiarism detection—matching or exceeding industry leaders like Turnitin. Our plagiarism detector scans against 91+ billion web pages, academic databases, journals, and publications for comprehensive coverage.
✅ AI Detection Included
Every Red Paper scan includes AI detection at no extra cost. We identify content from ChatGPT, Claude, Gemini, Copilot, and 15+ AI writing tools. This capability alone makes Red Paper essential in 2026—something Grammarly check simply cannot offer.
✅ Advanced Paraphrase Detection
Our semantic analysis algorithms catch paraphrased plagiarism that basic tools miss. Red Paper examines meaning and structure, not just word matching, to identify reworded content from original sources.
✅ Detailed Source Reports
Get comprehensive similarity reports with direct links to matched sources, percentage breakdowns by source, and sentence-level highlighting. Our reports provide the documentation students and educators need for academic integrity verification.
✅ Affordable Pay-Per-File
No expensive subscriptions required. Red Paper's credit system lets you pay only for what you use—₹10 per credit (250 words). Check one essay or hundreds, scaling costs to your actual needs rather than paying monthly for features you rarely use.
🎯 Red Paper vs Grammarly: Key Differences
Primary Focus: Red Paper = Plagiarism & AI Detection | Grammarly = Grammar Checking
AI Detection: Red Paper = Included | Grammarly = Not Available
Database Size: Red Paper = 91B+ Sources | Grammarly = Limited ProQuest + Web
Pricing Model: Red Paper = Pay-Per-File | Grammarly = Monthly Subscription
Minimum Cost: Red Paper = ₹10/credit | Grammarly = $12/month minimum
Grammar Checking Comparison
Let's be fair: Grammarly excels at grammar. The Grammarly grammar check is industry-leading with advanced suggestions for clarity, tone, and style. But how does Red Paper's grammar checking compare?
Grammarly's Grammar Strengths
The grammar check grammarly feature offers real-time corrections across platforms, tone detection, vocabulary suggestions, and style improvements. For writers focused primarily on polishing prose, Grammarly's grammar checker free tier provides substantial value even without Premium.
Red Paper's Grammar Capabilities
Red Paper includes grammar checking as part of our Writing Assistant feature. We catch spelling errors, punctuation checker issues, grammatical mistakes, and sentence structure problems. While not as feature-rich as Grammarly's dedicated grammar tools, our checking handles essential corrections effectively.
The Verdict on Grammar
If grammar is your primary concern and plagiarism is secondary, Grammarly's grammar corrector offers more depth. But if you need comprehensive plagiarism detection with adequate grammar support, Red Paper provides both without requiring a separate subscription for each need.
AI Detection: The Missing Feature in Grammarly
In 2026, any serious plagiarism checker must include AI detection. ChatGPT and similar tools have fundamentally changed content creation. Students can generate essays in seconds. Content creators use AI for drafting. The ability to detect AI-generated text is no longer optional—it's essential.
🚫 Grammarly's AI Detection Gap
Despite being a major writing tool company, Grammarly has not added AI detection to their plagiarism detector. Users searching for comprehensive content verification find that Grammarly check catches grammar issues and basic plagiarism but completely misses AI-generated content.
This means a student could submit an entirely ChatGPT-written essay, run it through Grammarly plagiarism checker, receive a clean report, and assume their work is submission-ready—when in reality, any decent AI detector would flag it immediately.
✅ Red Paper's Comprehensive AI Detection
Red Paper detects content from all major AI writing tools:
• ChatGPT (all versions including GPT-4)
• Claude (Anthropic)
• Google Gemini
• Microsoft Copilot
• Jasper, Copy.ai, Writesonic
• 15+ additional AI tools
Our AI detection uses multi-layered analysis including perplexity testing, burstiness evaluation, and linguistic fingerprinting to achieve 99% accuracy. Every plagiarism scan automatically includes AI detection—no separate tool or additional payment required.
Pricing Comparison: Value for Money
Understanding the true cost of each tool helps determine value. Let's break down what you actually pay for Grammarly plagiarism checker versus Red Paper.
💰 Grammarly Pricing
Free Tier: Grammar checking only—NO plagiarism detection
Premium Monthly: $30/month ($360/year)
Premium Annual: $12/month ($144/year)
Business: $15/member/month
To access Grammarly plagiarism detector, you must subscribe to Premium. There's no way to pay for just plagiarism checking—you're forced into the full subscription even if grammar checking isn't your priority.
💰 Red Paper Pricing
Pay-Per-File: ₹10 per credit (250 words)
50 Credits: ₹450 (10% savings)
100 Credits: ₹800 (20% savings)
250 Credits: ₹1,750 (30% savings)
Subscriptions: Available for regular users with additional discounts
📊 Real-World Cost Examples
Scenario 1: Student checking 5 essays per semester
• Grammarly: $72-180/semester (forced 6-month minimum)
• Red Paper: ~₹400-500 total (pay only for what you use)
Scenario 2: Occasional blogger checking monthly posts
• Grammarly: $144-360/year subscription required
• Red Paper: ~₹120-240/year (12 posts at ~₹10-20 each)
Scenario 3: Educator checking 50 student papers
• Grammarly: $144-360/year (same subscription cost)
• Red Paper: ~₹2,000-4,000 depending on paper length
For occasional users, Red Paper's pay-per-file model delivers massive savings. Grammarly's subscription makes sense only if you need constant grammar checking AND don't mind paying premium prices for basic plagiarism detection.
Feature-by-Feature Comparison
| Feature | Red Paper | Grammarly |
|---|---|---|
| Plagiarism Detection Accuracy | 99% | ~85-90% |
| AI Content Detection | ✅ Included (99% accuracy) | ❌ Not Available |
| Database Coverage | 91B+ Sources | ProQuest + Web |
| Grammar Checking | ✅ Included | ✅ Industry-Leading |
| Free Plagiarism Checking | ✅ Free Credits for New Users | ❌ Premium Only |
| Pay-Per-File Option | ✅ ₹10/credit (250 words) | ❌ Subscription Only |
| Minimum Monthly Cost | ₹10 (one-time) | $12/month |
| Paraphrase Detection | ✅ Advanced | ⚠️ Basic |
| Content Storage | ✅ Never Stored | ⚠️ May Be Stored |
Who Should Choose Which Tool?
Choose Grammarly If:
• Grammar and style improvement is your primary need
• You write constantly and need real-time corrections everywhere
• Plagiarism checking is secondary and occasional
• You don't need AI detection capabilities
• You're comfortable with monthly subscription pricing
Choose Red Paper If:
• Plagiarism detection is your primary concern
• You need AI detection (essential in 2026)
• You prefer pay-per-file over subscriptions
• Academic integrity verification is important
• You want the best plagiarism checker accuracy
• Privacy matters—you don't want content stored
• You need comprehensive similarity reports with source links
🚀 Try Red Paper Free Today
Experience the difference of purpose-built plagiarism detection with AI checking included. New users receive free credits—no subscription required.
Start Free Trial →Frequently Asked Questions
Can I use both Grammarly and Red Paper together?
Absolutely! Many users leverage Grammarly's grammar checker free tier for real-time writing assistance, then run final drafts through Red Paper for comprehensive plagiarism detection and AI checking. This combination gives you best-in-class capabilities for both grammar and originality verification.
Is Red Paper's grammar checking good enough to replace Grammarly?
For essential grammar, spelling, and punctuation checker needs, Red Paper handles corrections effectively. However, if you need advanced style suggestions, tone detection, and vocabulary enhancement, Grammarly's dedicated grammar corrector offers more depth. Consider your primary needs when choosing.
Why doesn't Grammarly offer AI detection?
Grammarly's core business is grammar assistance, not content verification. Adding AI detection would require significant technology investment in a different domain. This is precisely why purpose-built tools like Red Paper exist—to fill gaps that generalist writing tools don't address.
Which tool do teachers prefer?
Educators generally prefer dedicated plagiarism checkers like Red Paper or Turnitin for evaluating student work. While Grammarly plagiarism detection works for basic checking, academic settings require the comprehensive reports, AI detection, and accuracy that specialized tools provide.
Conclusion
The Grammarly plagiarism checker is a convenient add-on for users already paying for Grammarly Premium's grammar features. But as a dedicated plagiarism solution, it falls short—limited database coverage, no AI detection, basic paraphrase catching, and subscription-only access make it inadequate for serious content verification needs.
Red Paper delivers what modern users actually need: 99% accurate plagiarism detection, comprehensive AI checking, advanced paraphrase identification, detailed source reports, and affordable pay-per-file pricing. For anyone prioritizing originality verification—students, educators, content creators, or professionals—Red Paper is simply the better plagiarism checker choice in 2026.
The bottom line? Use Grammarly for grammar. Use Red Paper for plagiarism and AI detection. Or save money by using Red Paper for everything—we include grammar checking too.
🏆 The 2026 Verdict: Red Paper Wins for Plagiarism Detection
Detection Accuracy: Red Paper 99% vs Grammarly ~85-90%
AI Detection: Red Paper ✅ vs Grammarly ❌
Value for Money: Red Paper pay-per-file vs Grammarly $144+/year subscription
Database Coverage: Red Paper 91B+ sources vs Grammarly limited ProQuest
Privacy: Red Paper never stores content vs Grammarly may retain data
Best For: Red Paper = Plagiarism & AI | Grammarly = Grammar & Style