Grammarly vs QuillBot
Grammarly scores 8.3 to QuillBot's 7.3 among the AI writing assistants we rate, and is the better pick for 3 of the 4 kinds of buyer below.
Grammarly wins, 8.3 to 7.3
QuillBot's Premium plan costs $19.95 a month against Grammarly's Pro at $30 a month. Grammarly holds SOC 2 Type II and ISO 27001 certification; QuillBot's trust center lists neither. Grammarly also works inside Word, Google Docs, Outlook, Gmail and Slack, where QuillBot's add-in list is Word alone. Both check grammar and plagiarism, generate new text from a prompt, detect AI writing and rewrite AI text to read as human.
Pick Grammarly if you want SOC 2, ISO 27001 and wider app coverage.
Pick QuillBot if you want a cheaper plan and don't need extra add-ins.
Best for
Who each one suits, decided on the criteria that matter to that buyer and the checked facts where the two differ.
- Word, Google Docs, Outlook, Gmail and Slack add-ins: Word, google_docs, outlook, gmail, slack against Word
- Browsers it has an extension for: Chrome, edge, firefox, safari against Chrome, edge, safari
- Monthly price, cheapest paid plan: $19.95 against $30
- Your own style guide and terms: Grammarly yes, QuillBot does not say
- API: Grammarly yes, QuillBot does not say
- Single sign-on: Grammarly yes, QuillBot does not say
- SOC 2: Grammarly yes, QuillBot no
- ISO 27001: Grammarly yes, QuillBot no
How they score
Both are scored the same way, against the other AI writing assistants we rate, from facts on each vendor's own pages. Grammarly leads on 3 of 5 criteria.
Where they differ
Every point where the two vendors' published facts disagree, with a link to where each fact was read. "Not published" means the vendor does not say either way.
Published by only one of them
Where they match (10)
Pricing, plan by plan
Every plan each vendor publishes, monthly and yearly where both are offered.
Grammarly
QuillBot
Pros and cons
From each tool's full review, written from the same checked facts.
Grammarly
- Grammarly works across an impressive range of platforms including Chrome, Safari, Firefox, Edge, Windows, Mac, iOS, Android, Microsoft Word, and Google Docs.
- The plagiarism checker is built directly into the editor rather than being a separate export tool, a useful workflow for academic and content marketing use.
- Real-time grammar, spelling, and punctuation corrections remain reliable and are available even on the free plan.
- The Pro plan at $12/month billed annually unlocks full sentence rewrites, tone suggestions, and style clarity options at a competitive price point.
- Tone detection and brand voice features make it viable for enterprise teams managing content consistency across large organizations.
- Grammarly says it works across more than 500,000 apps and websites, making it one of the most broadly compatible writing tools.
- The free plan is significantly limited, though it does include tone detection and 100 AI prompts a month alongside basic grammar, spelling, and punctuation; most meaningful features still require a paid Pro subscription.
- Grammarly is now owned by Superhuman, which adds uncertainty about the product's long-term direction.
- Brand voice customization is heavily gated, with free users restricted to a single brand tone while unlimited options require an enterprise plan.
QuillBot
- Offers ten paraphrasing modes, which is significantly more than most competitors that typically offer three or four.
- Comprehensive feature set includes grammar checker, plagiarism detector, citation generator (APA, MLA, Chicago), AI Detector, Summarizer, and Translator covering 50+ languages.
- The Formal and Academic paraphrasing modes are especially useful for academic users.
- Continuously expanding platform with recent additions like Speech to Text, AI Business Plan Generator, and document editor.
- Accessible free tier makes core paraphrasing functionality available without payment, lowering the barrier to entry.
- Covers a wide range of writing use cases including cover letters, resumes, image generation, and a Co-Writer tool.
- Pricing is almost entirely invisible on the homepage, making it difficult to evaluate cost before committing.
- The rapid pace of feature additions raises questions about whether newer tools like the Business Plan Generator and Image Editor are fully polished.
- The broad feature surface area means not all tools are likely equally refined or reliable.
- Marketing language like 'used by professionals' can be misleading given the predominantly student user base.
- The sheer number of features makes it harder to evaluate the tool accurately, as quality varies significantly across them.
Grammarly vs QuillBot: common questions
Which is better, Grammarly or QuillBot?
Grammarly scores 8.3 and QuillBot 7.3 out of 10 among the AI writing assistants we rate. Grammarly is ahead on where it works, teams and control and privacy and security. QuillBot is ahead on pricing.
Is Grammarly or QuillBot cheaper?
Grammarly's cheapest paid plan is $12/mo (Pro plan, billed annually) and QuillBot's is $19.95/mo (Premium, monthly billing; $8.33/mo billed annually). Compare what each plan includes below before going on price alone.
What can Grammarly do that QuillBot cannot?
On the facts both vendors publish: sOC 2 and iSO 27001.
