Most writers use AI for generation. Smart writers use AI for editing and refinement.
Grammarly and ProWritingAid are the two best AI editing tools available right now. Neither is a content writer. Both are editors that make your writing dramatically better without replacing your voice.
The question for marketing teams: which one saves you time and improves your content more?
I’ve used both extensively across blog posts, emails, LinkedIn content, and sales copy. Here’s the honest comparison.
The Core Difference
Grammarly is optimized for speed and accessibility. It catches grammar, tone, and style issues in real-time, as you type. It feels like an invisible editor on your shoulder.
ProWritingAid is optimized for depth and learning. It provides detailed reports on your writing patterns, suggests improvements with educational context, and helps you improve as a writer over time.
If you want your content fixed quickly, Grammarly wins. If you want to understand why your writing is weak and improve it, ProWritingAid wins.
Speed and Workflow Integration
Grammarly
- Real-time checking: As you type, Grammarly highlights issues with a red underline (grammar), yellow underline (clarity), or blue underline (tone).
- Browser integration: Works in Gmail, LinkedIn, Google Docs, Twitter, basically everywhere you write.
- Fast feedback: You see suggestions instantly and can apply them with one click.
- Typical workflow: Write → fix issues → move on. Total overhead: 30 seconds per 500 words.
ProWritingAid
- Batch analysis: You write the full piece, then run it through ProWritingAid’s analyzer.
- Browser integration: Limited to their own editor and a few platforms. No Gmail integration.
- Detailed reports: You get a 10-15 page report on grammar, style, readability, word choice, etc.
- Typical workflow: Write → run analysis → review suggestions → decide which to implement → update → repeat. Total overhead: 10-15 minutes per 500 words.
Winner for speed: Grammarly by a significant margin.
Writing Quality Improvements
Here’s where it gets interesting. I tested both tools on the same piece of writing — a 1,500-word blog post.
Grammarly’s output:
- Fixed 8 grammar errors
- Flagged 12 clarity issues
- Suggested 5 tone adjustments
- Result: The post was grammatically correct and professional. No weird issues.
ProWritingAid’s output:
- Fixed 8 grammar errors (same ones)
- Flagged 12 clarity issues (same ones)
- Provided detailed analysis showing:
- Your most commonly used words (and suggested synonyms)
- Your sentence length distribution (and where it’s monotonous)
- Your readability score (and what that means)
- Specific “clichés” used (and alternatives)
- Result: The post was grammatically correct, more engaging, and more readable.
The same grammar fixes, but ProWritingAid went deeper on style and voice.
Real Writing Issues: What Each Catches
I deliberately wrote several sentences with different types of issues:
Issue 1: Passive voice where active would be stronger
Grammarly: Flagged it, suggested “change to active voice.” Helpful.
ProWritingAid: Flagged it, explained why passive voice weakens writing, showed the specific effect on readability, and suggested active alternative. Educational.
Issue 2: Using the same word 7 times in 300 words
Grammarly: Didn’t catch this. Grammarly is good at grammar and tone, but doesn’t track word repetition well.
ProWritingAid: Caught it immediately, showed a “word frequency” chart, and suggested synonyms.
Issue 3: Sentence too long (47 words)
Grammarly: Flagged it as “clarity” issue, suggested breaking it up.
ProWritingAid: Flagged it, showed your average sentence length, explained why this sentence is an outlier, and suggested where to break it.
Issue 4: Corporate jargon
Grammarly: Catches obvious stuff like “leverage” or “synergy,” suggests alternatives.
ProWritingAid: Has a database of clichés specific to business writing, flags them with context, and suggests fresher alternatives.
Winner for quality: ProWritingAid, but Grammarly is close enough for most use cases.
The Learning Curve
Grammarly
- 30 seconds to start using (install plugin, turn it on)
- Suggestions appear naturally in your workflow
- No learning required
ProWritingAid
- 5 minutes to understand the interface
- Reports are detailed but dense
- First few uses are confusing (there are a lot of options)
- After 3-4 uses, you understand what each metric means
Grammarly is more accessible. ProWritingAid has a learning curve but teaches you more about writing.
Pricing and Cost-Benefit
Grammarly
- Free version: Basic grammar/spell checking only
- Premium: $12/month or $120/year. Includes tone detection, clarity suggestions, plagiarism check.
- Business: $15/month per user (team licenses) + plagiarism check + advanced tone.
ProWritingAid
- Limited free version (10 reports/month)
- Annual subscription: $120/year (same as Grammarly Premium)
- Lifetime license: $240 (one-time)
Cost is essentially equal.
ROI Calculation
Here’s where this gets real. Let’s say you’re a marketing team producing 40 blog posts per month.
Without editing tools:
- Posts ship with an average of 3-5 small errors per post
- Posts have mediocre readability
- ~10% of posts get flagged for revision after publishing
With Grammarly:
- Posts ship near-error-free
- Readability improves ~15%
- Revision rate drops to ~2%
- Time investment: 30 seconds per post
With ProWritingAid:
- Posts ship error-free
- Readability improves ~25%
- Revision rate drops to <1%
- Clichés and weak word choices are caught
- Time investment: 10 minutes per post
Over a month:
- Grammarly: 20 minutes investment, improves 40 posts slightly
- ProWritingAid: 400 minutes investment, improves 40 posts significantly
The question: Is that extra time investment worth it?
If you’re: A solo blogger or a fast-moving content team → Grammarly If you’re: Building a brand where writing quality is crucial (thought leadership, premium content) → ProWritingAid
The Verdict: Which One Wins?
Neither is objectively “better.” They serve different needs.
Choose Grammarly if:
- You write quickly and prefer real-time feedback
- Grammar and tone are your main concerns
- You can’t spare 10 minutes per piece for detailed review
- You write across many platforms (Gmail, LinkedIn, etc.)
Choose ProWritingAid if:
- You want to improve as a writer, not just fix errors
- You’re producing premium content where every word matters
- You have time for deeper analysis
- Your writing has consistent weak patterns (repetition, passive voice, etc.)
The Hybrid Approach
Best strategy: Use both.
Write in Grammarly for real-time feedback. Once the piece is done, paste it into ProWritingAid for a final quality pass. The combo gives you speed (Grammarly) + depth (ProWritingAid) with total overhead of about 5 minutes per post.
Cost: $240/year for the combo. For a content team, that’s the cheapest investment you’ll make with the highest ROI.
What Neither Does Well
- Voice uniqueness: Both tools help you write clearly, but they can’t ensure you sound like yourself. You need editorial voice.
- Fact checking: Neither checks if your claims are true. That’s still on you.
- SEO optimization: Neither understands keyword strategy. Pair these with Surfer SEO if SEO optimization is important.
- Tone matching: Grammarly and ProWritingAid optimize for “professional” or “academic.” They struggle with highly specific brand voices.
The Real Lesson
Writing is the multiplier for marketing teams. A marketing manager who writes 30% better content gets significantly better conversion rates, better audience building, better leadership perception.
Using an AI editing tool is the highest ROI improvement you can make for $120/year.
The question isn’t “do I need this?” It’s “which one matches my workflow better?”
For most teams: Grammarly for day-to-day, ProWritingAid for premium pieces.
AI Marketing Picks covers tools that improve your output and your team’s effectiveness. More at aimarketingpicks.com.