Grammarly vs ProWritingAid: Which AI Grammar Tool Is Worth It?

Everyone knows Grammarly—it’s the grammar checker you’ve probably already tried. ProWritingAid is the one writers whisper about as the “real” alternative.

I’ve used both extensively. Grammarly has been in my workflow for four years; ProWritingAid for two. And here’s the thing: they take fundamentally different approaches to making your writing better. The right choice depends entirely on what kind of writer you are—and honestly, what you’re hoping to get out of a writing tool in the first place.

The Core Difference (And Why It Matters)

Grammarly prioritizes accessibility and speed. It catches errors quickly with minimal friction, and its suggestions are immediate, actionable, and usually right. It’s optimized for “fix this now and move on.”

ProWritingAid prioritizes depth. It offers detailed reports, style analysis, and craft-level feedback that goes way beyond comma placement. It’s trying to teach you to be a better writer, not just fix your current mistakes.

Quick Comparison

Accuracy: The Real Comparison

I ran both tools on 50 documents I’d written over the past year—documents where I already knew the errors existed. Here’s what I found:

Grammar & Spelling

Tie. Both catch standard errors reliably. Grammarly flags slightly more potential issues, but that comes with more false positives. ProWritingAid is more conservative, which means fewer “actually, that was intentional” moments.

Punctuation

Grammarly wins. Particularly with comma placement and semicolon usage. I noticed ProWritingAid missing nuanced punctuation errors that Grammarly caught. For business writing where punctuation matters, this difference is real.

Style & Clarity

ProWritingAid wins—decisively. Its suggestions go way deeper. It identifies overused words I’d become blind to, sentence variety issues I never noticed, and readability problems Grammarly simply ignores. If you want to actually improve your writing craft, ProWritingAid delivers more here.

Context Understanding

Grammarly wins. It better understands what I’m trying to say, especially in professional writing. ProWritingAid sometimes makes suggestions that would technically be “correct” but would make the writing worse. You need to be more careful about accepting its suggestions blindly.

Feature Deep Dive

Grammarly’s Strengths

Real-time feedback that doesn’t slow you down: Suggestions appear as I write with virtually no lag. After four years, I barely notice it’s running—it just feels like part of how I write.

Tone detection that’s actually useful: Grammarly tells me when I’m sounding too formal, too tentative, or unintentionally harsh. For client emails, this has saved me more than once.

GrammarlyGO (the AI assistant): Their new AI writing feature helps generate, rewrite, and improve text. It’s basically ChatGPT embedded in your workflow. Is it revolutionary? Not really. But the convenience of having it right there is nice.

Goal setting: I can tell Grammarly who I’m writing for and what I’m trying to achieve. It adjusts suggestions accordingly. Writing to executives? Different suggestions than writing to developers.

Clean interface: Everything is clear, explanations are brief, and the experience feels polished in a way that ProWritingAid doesn’t quite match.

ProWritingAid’s Strengths

Writing reports that teach you something: This is ProWritingAid’s killer feature, and it’s genuinely impressive. Reports analyze:

• Overused words (I discovered I write “actually” way too much)
• Sentence length variation (apparently mine were too uniform)
• Readability scores
• Dialogue tag usage (useful for fiction)
• Pacing analysis
• Cliches and redundancies I’d become blind to

I’ve genuinely become a better writer because of these reports. That’s not something I can say about Grammarly.

Fiction-specific features: ProWritingAid understands creative writing. It won’t flag intentional fragments, dialogue quirks, or stylistic choices that Grammarly would question. If you’re writing a novel, this matters.

Thesaurus integration that’s actually useful: Click any word for synonyms, with context about formality and usage. Way more detailed than Grammarly’s basic alternatives list.

Lifetime pricing: Pay $399 once, use forever. I did the math—it pays for itself in about 3 years compared to Grammarly’s subscription.

Integrations for serious writers: Works with Scrivener (crucial for book authors), Google Docs, and most writing platforms.

Who Should Use What (Honest Recommendations)

Choose Grammarly If:

• You write primarily professional or business content
• You want something that “just works” without fiddling with settings
• You value speed and convenience over depth of analysis
• You’re not trying to become a better writer—you just need to write clearly
• You live in Google Docs or your browser
• Budget isn’t your primary concern

Choose ProWritingAid If:

• You write fiction, creative nonfiction, or long-form content
• You genuinely want to improve as a writer (not just fix today’s errors)
• You use Scrivener or other dedicated writing apps
• You’d rather pay once than subscribe forever
• You need plagiarism checking included (it’s an expensive add-on for Grammarly)
• You’re willing to spend time with detailed analysis instead of quick fixes

Real Scenarios: What Would I Actually Use?

Marketing professional writing emails and reports Grammarly. Quick fixes, tone detection, professional polish. You don’t need deep craft analysis for a status update email—you need to ship it without embarrassing typos.

Novelist writing their first book ProWritingAid, no question. Writing reports, pacing analysis, Scrivener integration—all of it matters. The craft-level feedback will actually make your book better, not just cleaner.

Blogger publishing 2-3 posts weekly Honestly, it depends. Do you want to publish faster (Grammarly) or become a better writer over time (ProWritingAid)? Both are valid goals. I use Grammarly for client work and ProWritingAid for my own blog.

Academic writing research papers Grammarly handles formal academic tone better. ProWritingAid’s reports can help with clarity, but Grammarly’s suggestions feel more aligned with what reviewers expect.

Content agency with multiple writers Grammarly Business. Team features, shared style guides, and consistent suggestions across writers. For AI-generated content that needs polishing, see our best AI marketing tools guide. ProWritingAid doesn’t match the team management capabilities.

The Pricing Math (I Did It So You Don’t Have To)

Grammarly costs $12/month on annual billing. No lifetime option—you’re subscribing forever. Over 3 years, that’s $432. Over 5 years, $720.

ProWritingAid offers a $399 lifetime license. Pay once. Done. If you write regularly and plan to keep writing, this pays for itself in under 3 years.

For budget-conscious writers (or anyone allergic to subscriptions), ProWritingAid’s lifetime deal is hard to ignore. It’s why I eventually bought it, even though I’d been a happy Grammarly user for years.

What Frustrated Me About Each

Grammarly Annoyances

• Pro gets expensive over time—those annual renewals add up
• GrammarlyGO feels tacked on rather than thoughtfully integrated
• Some suggestions are overly cautious (not everything needs to be “more clear”)
• The free tier is so limited it’s almost just a demo

ProWritingAid Annoyances

• Interface feels dated—it works, but it’s not pretty
• The reports can be overwhelming; sometimes I just want a quick fix
• Noticeably slower performance on documents over 5,000 words
• False positives in creative writing when I’ve intentionally broken “rules”

The AI Writing Features (Are They Worth It?)

Both tools are adding AI writing capabilities beyond grammar checking. But are they actually useful?

GrammarlyGO helps with generation, rewriting, and ideation. I’ve used it. It’s convenient having it right there, but it’s not doing anything ChatGPT doesn’t do. It’s a nice-to-have, not a reason to choose Grammarly.

ProWritingAid’s AI is less developed but focuses on craft improvement rather than content generation. Different philosophy, aligned with their overall approach.

My Final Verdict After Years of Using Both

Grammarly is the better tool for most people. It’s faster, cleaner, and handles professional writing excellently. If you just want your emails and reports to be error-free without thinking too hard about it, Grammarly delivers.

ProWritingAid is the better tool for serious writers. The depth of analysis, craft-level feedback, and lifetime pricing make it valuable for those genuinely committed to improving. It’s taught me things about my own writing that Grammarly never surfaced.

What do I actually use? Both. Grammarly for quick client work where speed matters. ProWritingAid for longer pieces where I want to level up. That might sound like a cop-out, but it’s the truth.

You can’t go wrong with either. They’re both good tools that do different things well. The “best” choice is simply the one that matches how you actually write and what you’re trying to get better at.

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For official product details, visit Grammarly and ProWritingAid.