Grammarly vs QuillBot: Best AI Writing Assistant?

Every writer needs a second pair of eyes, and AI writing assistants have become that essential safety net. Grammarly and QuillBot are the two most popular tools for polishing your writing, but they approach the task from different angles. Grammarly is a comprehensive writing assistant that checks grammar, style, tone, and clarity. QuillBot specializes in paraphrasing and rewriting, helping you express ideas in new ways.

Understanding the differences between these tools will help you choose the one that best fits your writing workflow.

Quick Overview

Feature Comparison

Grammar and Spelling

Grammarly is the undisputed champion of grammar checking. It catches everything from basic spelling errors to complex grammatical issues like misplaced modifiers, subject-verb agreement problems, and incorrect punctuation. Beyond basic corrections, Grammarly explains why each suggestion is made, helping you improve your writing skills over time.

QuillBot includes a grammar checker, but it is not as comprehensive as Grammarly's. It catches common errors effectively but misses some of the nuanced issues that Grammarly identifies. Grammar checking is a secondary feature for QuillBot rather than its primary focus.

Paraphrasing and Rewriting

QuillBot's paraphrasing tool is its standout feature. It offers multiple rewriting modes — Standard, Fluency, Formal, Simple, Creative, Expand, and Shorten — each producing distinctly different outputs. This flexibility is invaluable for academic writers who need to avoid plagiarism, content creators who want to repurpose content, or anyone looking to express ideas differently.

Grammarly offers sentence rewriting suggestions in its premium tier, but the functionality is more limited. It focuses on clarity and conciseness improvements rather than full paraphrasing. For dedicated rewriting needs, QuillBot is significantly more capable.

Tone and Style

Grammarly's tone detector analyzes your writing and tells you how it is likely to come across to readers — formal, friendly, confident, concerned, etc. The premium version lets you set tone goals and receive suggestions to match your desired tone. This feature is particularly useful for professional communication.

QuillBot's tone adjustment happens through its paraphrasing modes. Switching between Formal, Simple, or Creative modes effectively changes the tone, but it is less precise than Grammarly's dedicated tone analysis.

Plagiarism Detection

Both tools offer plagiarism detection in their premium tiers. Grammarly's plagiarism checker scans against billions of web pages and academic databases, providing detailed reports with source links. QuillBot's plagiarism checker is competent but has a smaller database for comparison.

Integration Ecosystem

Grammarly integrates with virtually everything — browsers, Microsoft Office, Google Docs, email clients, Slack, and many other platforms. Its browser extension works across any text field on the web, providing real-time writing assistance everywhere you type.

QuillBot's integration is more limited. It offers a browser extension, Microsoft Word add-in, and Google Docs integration, but it does not cover as many platforms as Grammarly.

Pricing Comparison

Grammarly: Free tier with basic grammar and spelling checks. Premium at $12/month (billed annually) or $30/month (billed monthly). Business plan at $15/member/month.

QuillBot: Free tier with limited paraphrasing (125 words) and 2 modes. Premium at $9.95/month (billed annually) or $19.95/month (billed monthly).

QuillBot is more affordable at every tier. However, Grammarly's free tier is more generous and useful for everyday writing needs.

Pros and Cons

Grammarly Pros

• Best-in-class grammar checking
• Comprehensive tone and style analysis
• Extensive integration ecosystem
• Excellent browser extension
• Educational explanations for corrections

Grammarly Cons

• More expensive than QuillBot
• Paraphrasing features are limited
• Premium feels necessary for full value
• Can be overly aggressive with suggestions

QuillBot Pros

• Best paraphrasing tool available
• Multiple rewriting modes
• More affordable pricing
• Good summarization feature
• Effective for academic writing

QuillBot Cons

• Grammar checker less comprehensive
• Fewer integrations
• Free tier quite limited
• Less useful for original content creation

Who Should Choose Which?

Choose Grammarly if your primary need is improving the quality of your original writing. It is essential for professionals who write emails, reports, and documents daily and want to ensure everything is polished, clear, and appropriately toned.

Choose QuillBot if you frequently need to paraphrase, rewrite, or rework existing text. It is ideal for students avoiding plagiarism, content creators repurposing material, and writers who want to explore different ways to express ideas.

Conclusion

Grammarly and QuillBot are not really competitors — they are complementary tools that serve different writing needs. Grammarly is the better overall writing assistant for grammar, tone, and clarity. QuillBot is the better paraphrasing and rewriting tool for transforming existing text. Many writers use both: Grammarly for daily writing assistance and QuillBot for specific rewriting tasks. If you can only pick one, choose Grammarly for general writing improvement or QuillBot if paraphrasing is your primary need.