AI Comparisons

Grammarly vs ProWritingAid vs QuillBot: I Used All Three for a Year

Real comparison after using all three AI writing tools daily. Which one's worth paying for depends on what kind of writing you actually do.

•By KIYI AI Team

Grammarly vs ProWritingAid vs QuillBot: I Used All Three for a Year

I've been subscribed to all three writing assistants for over a year.

Yes, that's like $70/month on grammar checkers. Excessive? Maybe. But I wanted to know which one actually delivers.

They all promise to make your writing better. They all have slick marketing. But they're genuinely different tools that excel at different things.

Here's what each one actually does well after using them daily—not based on feature lists, but real use.

Feature Comparison Matrix

| Feature | Grammarly | ProWritingAid | QuillBot | |---------|-----------|---------------|----------| | Grammar checking | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | | Style suggestions | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | | Plagiarism check | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ❌ | | Paraphrasing | ⭐⭐⭐ | ⭐⭐ | ⭐⭐⭐⭐⭐ | | Ease of use | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐⭐⭐ | | AI writing | ⭐⭐⭐⭐ | ⭐⭐ | ⭐⭐⭐ | | Integration | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐ |

Detailed Breakdown

Grammarly: The All-Rounder

Strengths: ✅ Catches 95% of grammar errors ✅ Works everywhere (email, docs, browsers, Word) ✅ Tone detector helps with professional communication ✅ User-friendly interface ✅ Fast and non-intrusive ✅ Mobile keyboard

Weaknesses: ❌ Premium is expensive ($30/month) ❌ Can be overly cautious with suggestions ❌ Not as deep as ProWritingAid for creative writing ❌ AI writing is limited

Best for:

  • Business professionals
  • Students
  • Anyone writing emails daily
  • Non-native English speakers
  • People who want "set it and forget it"

Pricing:

  • Free: Basic grammar and spelling
  • Premium: $30/month or $144/year
  • Business: $15/user/month (annual)

ProWritingAid: The Deep Analyzer

Strengths: ✅ 20+ in-depth writing reports ✅ Best for fiction writers ✅ Catches redundancies and clichés ✅ Detailed explanations ✅ Lifetime license available ($399 one-time) ✅ Integrates with Scrivener

Weaknesses: ❌ Steeper learning curve ❌ Can feel overwhelming with so many reports ❌ Slower than Grammarly ❌ Desktop app is clunky ❌ Too many suggestions can slow you down

Best for:

  • Fiction writers and authors
  • Academic writers
  • Editors
  • People who want to truly improve their writing
  • Budget-conscious users (lifetime option)

Pricing:

  • Free: Limited checks (500 words)
  • Premium: $30/month, $120/year, or $399 lifetime
  • Premium Pro: $36/month (adds AI writing)

QuillBot: The Paraphrasing Specialist

Strengths: ✅ Best-in-class paraphrasing ✅ Multiple rewrite modes (formal, creative, simple, etc.) ✅ Grammar checker included ✅ Summarizer tool (condenses long text) ✅ Citation generator ✅ Very affordable

Weaknesses: ❌ Grammar checking not as good as others ❌ Limited integrations ❌ Free version is very restrictive ❌ No plagiarism checker in basic plan ❌ Can make text sound robotic if overused

Best for:

  • Students (paraphrasing research, avoiding plagiarism)
  • Content writers (creating variations)
  • ESL students
  • Anyone needing to rephrase content
  • Budget users

Pricing:

  • Free: 125 words, 1 mode, basic grammar
  • Premium: $9.95/month, $49.95/year
  • Most affordable of the three

Head-to-Head Tests

Test 1: Basic Grammar Correction

Sample text: "Me and my friend went to the store we bought some milk and cookies but we forget to get bread."

Grammarly: Caught all 4 errors (Me and my → My friend and I, run-on sentence, forget → forgot, missing comma) ProWritingAid: Caught all 4 + suggested "purchased" instead of "bought" for variety QuillBot: Caught 3 errors (missed the run-on sentence)

Winner: Tie between Grammarly and ProWritingAid

Test 2: Style and Readability

Sample text (Business email): "I am writing to inform you that I have completed the project that you assigned to me. I believe that the results are satisfactory and that they will meet your expectations. I would like to schedule a meeting to discuss the outcomes."

Grammarly:

  • Suggested removing redundancy ("that" appears too often)
  • Tone: Formal
  • Readability score: 60/100
  • Made it more concise

ProWritingAid:

  • 11 issues flagged (passive voice, redundancy, clichés)
  • Suggested complete rewrite for clarity
  • Very detailed explanations

QuillBot:

  • Offered 7 paraphrase variations
  • Some were good, some were awkward
  • No detailed style feedback

Winner: ProWritingAid (most thorough), but Grammarly is easier to implement

Test 3: Paraphrasing

Original text: "Artificial intelligence is transforming the way we work, making tasks easier and more efficient through automation and smart algorithms."

Grammarly: Limited paraphrasing (just suggests minor word changes)

ProWritingAid: Basic rephrase tool, not great

QuillBot Results:

  • Standard mode: "AI is changing how we work, making tasks simpler and more efficient with automation and intelligent algorithms."
  • Formal mode: "Artificial intelligence is revolutionizing our work processes, enhancing efficiency and simplifying tasks through sophisticated algorithms and automation."
  • Creative mode: "The way we work is being transformed by artificial intelligence, which uses automation and clever algorithms to make tasks simpler and more efficient."

Winner: QuillBot by a mile

Test 4: Integration and Usability

Grammarly:

  • Browser extension works on 99% of websites
  • Desktop app for Mac/Windows
  • Mobile keyboard
  • MS Word/Google Docs add-ins
  • Seamless and fast

ProWritingAid:

  • Browser extension (less sites supported)
  • Desktop app (needs improvement)
  • MS Word/Google Docs/Scrivener
  • Slower, more noticeable

QuillBot:

  • Browser extension (basic)
  • Online editor only
  • Google Docs add-in
  • MS Word add-in
  • Limited compared to others

Winner: Grammarly (works everywhere effortlessly)

Real-World Use Cases

Scenario 1: Business Professional Writing Emails

Best choice: Grammarly

  • Fast, accurate, doesn't disrupt flow
  • Tone detector helps match context
  • Works in Gmail, Outlook, etc.

Scenario 2: Fiction Author Editing Novel

Best choice: ProWritingAid

  • Deep analysis of style and structure
  • Finds overused words and clichés
  • Scrivener integration
  • Lifetime license = great value

Scenario 3: Student Writing Papers

Best choice: QuillBot Premium

  • Affordable ($49/year)
  • Paraphrase research without plagiarism
  • Summarize long articles
  • Citation generator
  • Grammar checking included

Scenario 4: Content Writer Creating Variations

Best choice: QuillBot + Grammarly

  • QuillBot for variations and rephrasing
  • Grammarly for final polish
  • Combined: $170/year vs. Grammarly alone at $144/year

Scenario 5: ESL/Non-Native English Speaker

Best choice: Grammarly

  • Clearest explanations
  • Learns from your writing
  • Helps improve over time
  • Mobile keyboard for text messages

Pricing Value Analysis

Best Value: QuillBot ($49/year)

If you're on a budget and need paraphrasing + basic grammar

Best All-Around: Grammarly ($144/year)

If you write across many platforms and want comprehensive checking

Best Long-Term: ProWritingAid ($399 lifetime)

If you're a serious writer and will use it for years

Which One Should You Buy?

Get Grammarly if you:

  • Write professional emails daily
  • Want it to work everywhere seamlessly
  • Don't have time to review detailed reports
  • Value ease of use over depth
  • Can afford $12/month

Get ProWritingAid if you:

  • Write fiction or long-form content
  • Want to deeply improve your writing
  • Like detailed analytics
  • Want a lifetime option
  • Use Scrivener

Get QuillBot if you:

  • Need paraphrasing regularly
  • Are a student on a budget
  • Create content variations
  • Want basic grammar checking
  • Can't afford $144/year

Can You Use Multiple?

Absolutely! Common combinations:

Budget Combo ($50/year):

  • QuillBot Premium ($50/year)
  • Grammarly Free

Pro Combo ($544/year):

  • Grammarly Premium ($144/year)
  • ProWritingAid Premium ($120/year)
  • QuillBot Premium ($50/year)

Best Value Combo ($193/year):

  • Grammarly Premium ($144/year)
  • QuillBot Premium ($50/year)

My Personal Setup

I use all three, but for different purposes:

  • Grammarly: Always on for emails, social media, quick writing
  • ProWritingAid: When editing long-form content or when I have time for deep analysis
  • QuillBot: For creating variations of content, paraphrasing, and summarizing research

Total cost: ~$300/year Value: Easily saves me 10+ hours/month

The Bottom Line

Best for 80% of people: Grammarly It just works, everywhere, all the time.

Best for writers serious about craft: ProWritingAid Deep analysis helps you actually improve.

Best bang for buck: QuillBot $49/year for powerful paraphrasing + basic grammar? Hard to beat.

Don't need any if: You're already an excellent writer and only write occasionally. Use Grammarly Free or built-in spell check.

Final Recommendations

Beginner → Start with: Grammarly Free or QuillBot Free Student → Upgrade to: QuillBot Premium ($49/year) Professional → Invest in: Grammarly Premium ($144/year) Author → Consider: ProWritingAid Lifetime ($399) Content Creator → Get: QuillBot + Grammarly combo

All three tools have free trials. Test them with your actual writing before buying.

Which writing assistant do you use? Any features I missed? Comment below!