Grammarly vs QuillBot: Pay for Grammar, Paraphrasing, or Both?

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They solve different problems. **Grammarly** ($12/mo annual) is the better grammar, clarity, and tone checker — it polishes anything you write anywhere. **QuillBot** ($8.33/mo annual) is the better paraphraser and summarizer — 9 rewrite modes at a lower price. Most heavy writers end up with both ($20.33/mo combined) or pick Grammarly for editing and QuillBot's **free tier** for occasional paraphrasing.

The contenders

• Grammarly (now part of Superhuman) checks grammar, spelling, tone, and clarity across browser, desktop, and docs, with AI prompts and full-sentence rewrites. Its former “Premium” tier is now called Pro; the old Business plan folded into Pro/Enterprise.
• QuillBot is a paraphrase-first writing tool: 9 rewrite modes, summarizer, plagiarism checker, AI detector — plus a genuinely usable free plan.

Pricing as of October 2026 (official pricing pages):

Plan	Grammarly	QuillBot
Free	Basic grammar, tone, 100 AI prompts/mo	125-word paraphrases, 2 modes, basic checker
Entry paid	Pro: $30/mo monthly, $12/mo annual ($144/yr)	Premium: $19.95/mo monthly, $8.33/mo annual ($99.95/yr)
Quarterly	$60/3 months	—
Team/other	Enterprise custom (SSO, analytics)	Teams ~$7.50/seat/mo; student rate ~$6.25/mo

QuillBot is 31% cheaper per year ($99.95 vs $144) for the entry paid tier.

Test setup

We ran three documents through both tools:

1. A 1,000-word blog draft seeded with 30 errors (grammar, punctuation, wordiness, passive voice)
2. A dense academic paragraph to paraphrase at three intensities (light → aggressive)
3. A 2,500-word research piece needing a plagiarism check against the web

Metrics: errors caught vs. missed, false positives (flagging correct text), paraphrase meaning-preservation (rated by two human readers), and how much we accepted without rework.

Results

Metric	Grammarly Pro	QuillBot Premium
Seeded errors caught	27 / 30	22 / 30
False positives	3	5
Paraphrase quality (1–5, meaning kept)	3.2	4.4
Plagiarism check	25K words/mo, web sources	25K words/mo, web + academic db
Works in	Browser, desktop, docs, editors	Browser, Docs, Word add-in
Accept rate without rework	71%	64%

Grammarly caught more errors and — critically — invented fewer. Its contextual suggestions (“their” vs “there”, article agreement) were sharper. QuillBot’s paraphrase modes, its core competency, preserved meaning better at every intensity; Grammarly’s rewrite suggestions were more conservative and occasionally off-tone.

If your pain is "my writing has mistakes", buy Grammarly. If your pain is "I need this passage said a different way", buy QuillBot — or use its free tier, which covers casual paraphrasing at zero cost. Writers doing both jobs daily can justify owning both for about $20/mo.

Where Grammarly wins

• Error catching: 27/30 versus 22/30, with fewer annoying false flags.
• Coverage everywhere: it sits in your OS — email, Slack, CMS, docs — not just one editor.
• Tone & clarity: audience, formality, and concision suggestions are mature and specific.
• Full-sentence rewrites and 1,000–unlimited AI prompts on paid tiers.

Where QuillBot wins

• Paraphrasing: 9 modes (Standard, Fluency, Formal, Creative…) with a intensity slider Grammarly simply doesn’t have.
• Price: $8.33/mo versus $12/mo annual; student rate drops to ~$6.25.
• Free tier: 125-word paraphrases and 2 modes forever — enough for students on a budget.
• Summarizer: paste a long document, get a structured summary; Grammarly has no equivalent.
• Academic bent: citation-friendly output and an AI detector/humanizer bundle.

Who should pick what

Pick Grammarly if…

• English accuracy is professional currency (clients, publications, exec comms).
• You write in many apps and want one checker everywhere.
• You want the free tier for grammar and only occasionally paraphrase.

Pick QuillBot if…

• You paraphrase and summarize more than you draft from scratch.
• You are a student: the annual rate + student discount is unbeatable.
• You want a free tool that stays genuinely useful.

Buy both if…

• Writing is your job and $20.33/mo is less than one hour of editing time. Their overlap is smaller than it looks: checkers and paraphrasers are different organs.

The bottom line

Grammarly is the better-written-English machine; QuillBot is the better same-meaning-different-words machine. Start with the two free tiers this week — they cover most casual needs. When the limits bite (QuillBot’s 125 words, Grammarly’s basic rules), upgrade whichever you hit first; statistically, that will be the one matching your actual bottleneck.