Grammarly and QuillBot are two of the most popular AI writing tools among college students, but they solve different problems. Grammarly focuses on polishing writing you've already drafted, while QuillBot is built around paraphrasing, summarizing and citations. Here's how their free and paid plans compare so you can pick the right one for your coursework.
you mainly want to clean up grammar, clarity and tone in essays and reports you wrote yourself, and want those checks inside Google Docs, Word and your browser.
you want a cheaper paid plan, need help summarizing long readings, or want a citation generator and plagiarism checker bundled together.
| Feature | Grammarly | QuillBot |
|---|---|---|
| Main focus | Grammar, clarity and tone of your own writing | Paraphrasing, summarizing and citations |
| Free plan | Spelling and grammar checks, tone detection, 100 AI prompts/month | Paraphrase up to 125 words at a time (2 modes), basic grammar fixes, summarize up to 1,200 words, limited AI detector |
| Paid plan name | Grammarly Pro | QuillBot Premium |
| Paid price (monthly billing) | $30/month | See QuillBot's pricing page |
| Paid price (annual billing) | $144/year (about $12/month) | $8.33/month billed annually |
| Other billing | $60 every 3 months | See QuillBot's pricing page |
| Plagiarism checker | Pro only | Premium only (up to 25,000 words/month) |
| AI-text detector | Pro only | Limited on free, full on Premium |
| Citation help | Citation consistency checks (Pro) | Citation generator |
| AI prompts / generation | 100/month free, 2,000/month on Pro | Higher AI chat usage on Premium |
Prices and limits from each company's official pricing pages as of September 2026. They change often — check the official site before you buy.
Best for: polishing essays and reports you wrote yourself
Grammarly checks spelling, grammar, clarity and tone as you write, through its browser extension, desktop app and integrations with tools like Google Docs and Microsoft Word. The free plan covers core corrections and 100 AI prompts per month. Grammarly Pro adds full-sentence rewrites, tone adjustments, a plagiarism checker, AI-text detection, citation consistency checks and 2,000 AI prompts per month.
Why students use it:
Grammarly is our top pick for improving writing you've drafted yourself. Always review suggestions critically and follow your course's policy on AI writing tools.
Best for: summarizing readings, paraphrasing practice and citations on a budget
QuillBot is an AI writing toolkit that includes a paraphraser, summarizer, grammar checker, citation generator, plagiarism checker and AI detector. The free plan lets you paraphrase up to 125 words at a time in two modes and summarize up to 1,200 words. QuillBot Premium unlocks unlimited paraphrasing with more modes, summaries of up to 6,000 words, a plagiarism checker (25,000 words/month) and full AI-detector access. Premium can also be paused when you don't need it.
Why students use it:
Using AI to check grammar is allowed in most courses, but using it to paraphrase sources or rewrite AI-generated text so it looks like your own can violate academic integrity rules. Check your syllabus and your instructor's AI policy, and cite every source you use.
Explore our AI tools for writing and note-taking and our guide on how to use AI for research papers.
Choosing between proofreading and tutoring? Read our Grammarly vs ChatGPT for students.
Choosing a proofreading tool? Read our Grammarly vs ProWritingAid for students.