In 2025, writing assistants have evolved beyond spellcheckers. They now complete sentences, rewrite entire paragraphs, and help you express thoughts with clarity and speed. But which one suits your workflow — Compose AI, Grammarly, or Quillbot?
This guide compares these three AI-powered writing tools to help you pick the one that fits your writing, editing, and productivity goals.
Quick Comparison Table
| Feature | Compose AI | Grammarly | Quillbot |
|---|---|---|---|
| Best For | Fast typing & autocompletion | Grammar & tone improvement | Paraphrasing & citations |
| AI Writing Assistance | ✅ Predictive typing | ⚠️ Limited (tone suggestions) | ✅ Rewriting, summarizing |
| Chrome Extension | ✅ Yes | ✅ Yes | ✅ Yes |
| Grammar & Spellcheck | ❌ Basic | ✅ Best-in-class | ⚠️ Good |
| Paraphrasing Tool | ✅ Rewrite | ⚠️ Rewrite tone only | ✅ Advanced modes |
| Plagiarism Checker | ❌ No | ✅ Yes (premium) | ✅ Yes (premium) |
| Free Plan Available | ✅ Yes | ✅ Yes | ✅ Yes |
| Paid Plan Starts At | $9.99/month | $12/month | $8.33/month |
1. Compose AI
Overview:
Compose AI is a lightweight Chrome extension designed to reduce your typing time using smart autocomplete, inline suggestions, and rephrasing.
Best For:
Startup founders, marketers, and writers who want to write faster and smarter inside any text box (Gmail, Google Docs, etc.).
Key Features:
- GPT-powered autocomplete
- Inline sentence rephrasing
- Email response generator
- Works in Gmail, Google Docs, LinkedIn
- Keyboard shortcuts for productivity
Pros:
✔ Autocomplete saves time
✔ Free plan is generous
✔ Minimal, distraction-free UI
✔ Works across web tools
Cons:
✖ Not a grammar tool
✖ Limited tone control
✖ No mobile app or desktop app
Pricing:
Free plan available
Premium: $9.99/month
2. Grammarly
Overview:
Grammarly is the most well-known writing assistant, trusted by 30M+ users for grammar checks, tone suggestions, and professional writing help.
Best For:
Business writers, students, and professionals who want clean, error-free writing with tone and clarity enhancements.
Key Features:
- Real-time grammar & spelling
- AI rewrite (tone/formality)
- Tone detector + goals
- Plagiarism checker
- Works in Gmail, Word, Chrome, Slack, etc.
Pros:
✔ Best-in-class grammar and spellcheck
✔ Tone + clarity improvements
✔ Full desktop + browser experience
✔ Plagiarism checker included
Cons:
✖ Rewrite tool is tone-based, not creative
✖ Autocomplete limited
✖ Premium is pricey
Pricing:
Free plan available
Premium: $12/month
3. Quillbot
Overview:
Quillbot is built for paraphrasing, summarizing, and academic writing — with powerful rewrite modes and citation tools.
Best For:
Students, researchers, and bloggers who want clean, reworded content with flexibility.
Key Features:
- Paraphraser with 7+ tone modes
- Summarizer tool
- Plagiarism checker
- Citation generator
- Works via browser + Microsoft Word
Pros:
✔ Excellent paraphrasing options
✔ Fast summarization + citation tools
✔ Affordable pricing
✔ Works well for content rephrasing
Cons:
✖ Grammar suggestions are weaker
✖ UI can feel dated
✖ Not ideal for business tone polishing
Pricing:
Free plan available
Premium: $8.33/month (billed annually)
Use Case Recommendations
| Goal | Best Tool |
|---|---|
| Reduce writing time via autocomplete | Compose AI |
| Fix grammar and improve tone | Grammarly |
| Reword paragraphs and summarize | Quillbot |
| Academic citations + rewriting | Quillbot |
| Email reply shortcuts | Compose AI |
| Corporate tone & clarity | Grammarly |
Final Verdict
- Choose Compose AI if you’re focused on typing faster and rewriting inline — ideal for productivity junkies.
- Choose Grammarly if you need grammatical precision, tone suggestions, and professional polish.
- Choose Quillbot if you’re rephrasing, summarizing, or doing research-based writing.
