About 13; min
Grammarly is the household name. ProWritingAid is the writer’s choice. Both catch grammar errors, both offer AI writing help, but their pricing models are radically different. One offers a lifetime deal. The other charges $12-30/month forever. We compared every angle to help you pick the right editor for your writing.
Last updated: March 18, 2026. Prices sourced from grammarly.com and prowritingaid.com.
Pricing Comparison
| Grammarly | ProWritingAid | |
|---|---|---|
| Free | $0 (basic grammar, 100 AI prompts) | $0 (500-word limit per check) |
| Monthly | $30/mo | $30/mo |
| Annual | $12/mo ($144/yr) | $10/mo ($120/yr) |
| Lifetime | Not available | $399 one-time |
| Premium Pro (AI) | Included in Pro | $12/mo or $699 lifetime |
$432 vs $399 (3 years)
Grammarly annual: $144 × 3 = $432 over 3 years
ProWritingAid lifetime: $399 one-time, done
After 2.8 years, ProWritingAid is free. Grammarly keeps charging.
The lifetime deal is ProWritingAid’s biggest pricing advantage. If you’ll use a writing tool for 3+ years (and most writers will), the math strongly favors ProWritingAid.
Free Tier Comparison
| Grammarly Free | ProWritingAid Free | |
|---|---|---|
| Word limit | No limit | 500 words per check |
| Grammar/spelling | Yes | Yes (limited) |
| AI prompts | 100/month | None |
| Browser extension | Yes | Yes |
| Plagiarism check | No | No |
Free tier winner: Grammarly. No word limit is a massive advantage. ProWritingAid’s 500-word cap makes Free barely usable for real work.
Feature Comparison: Paid Plans
| Feature | Grammarly Pro ($12/mo) | ProWritingAid Premium ($10/mo) |
|---|---|---|
| Grammar & spelling | Yes | Yes |
| Style suggestions | Good | Deeper (20+ reports) |
| Tone detection | Yes | Limited |
| Clarity rewrites | Full-sentence rewrites | Suggestions only |
| AI writing assistant | 2,000 prompts/month | 50 AI Sparks/day (Premium Pro) |
| Plagiarism detection | Included | Extra cost (add-on) |
| Writing reports | Basic analytics | 20+ detailed reports |
| Readability score | Basic | Detailed (Flesch, grade level) |
| Overused words | Basic | Dedicated report |
| Pacing analysis | No | Yes (for fiction writers) |
| Dialogue tags | No | Yes (for fiction writers) |
| Scrivener integration | No | Yes |
| Lifetime option | No | $399 one-time |
Where Grammarly Wins
- Real-time, everywhere — Grammarly’s browser extension works in every text field: email, Slack, Google Docs, LinkedIn, Twitter. It’s always on. ProWritingAid’s extension is less seamless.
- AI writing assistant — 2,000 prompts/month for rewrites, generation, and tone adjustment. More powerful and more generous than ProWritingAid’s AI Sparks.
- Plagiarism detection included — built into the Pro plan. ProWritingAid charges extra.
- Clarity rewrites — Grammarly rewrites entire sentences for clarity. ProWritingAid suggests changes but doesn’t rewrite.
- Tone detection — real-time feedback on how your writing sounds (confident, friendly, formal). Useful for emails and professional communication.
- Better free tier — no word limits, basic grammar everywhere. Enough for casual users.
Where ProWritingAid Wins
- Depth of analysis — 20+ writing reports (style, sentence length, readability, overused words, transitions, pacing). Grammarly doesn’t go this deep.
- Fiction writing tools — pacing analysis, dialogue tag checks, and sentence variety reports. Purpose-built for authors.
- Lifetime pricing — $399 once vs $144/year forever. After 3 years, ProWritingAid is cheaper.
- Scrivener integration — direct integration with Scrivener, the most popular long-form writing tool. Grammarly doesn’t support Scrivener.
- Lower annual price — $120/year vs $144/year. Small but real savings.
- Better for learning — the detailed reports teach you about your writing patterns over time. Grammarly fixes; ProWritingAid teaches.
Who Should Pick What
Business emails and professional communication: Grammarly. Real-time suggestions in every text field, tone detection, and AI rewrites make it the productivity tool for professionals.
Fiction writers and authors: ProWritingAid. Pacing, dialogue, and style reports are purpose-built for long-form creative writing.
Students and academics: Grammarly for plagiarism checking (included). ProWritingAid if budget is tight (cheaper annual, or lifetime deal).
Long-term investment: ProWritingAid lifetime ($399). If you’ll write for 3+ years, it’s the better financial decision.
Casual users: Grammarly Free. No word limits, works everywhere. ProWritingAid Free’s 500-word cap is too restrictive.
Want the best AI writing help: Grammarly. The 2,000 AI prompts/month and sentence rewrites are significantly ahead.
Frequently Asked Questions
Can I use both Grammarly and ProWritingAid?
Technically yes, but running two writing extensions simultaneously causes conflicts. Pick one as primary. Many authors use Grammarly for emails and ProWritingAid for manuscript editing.
Is ProWritingAid’s lifetime deal worth it?
If you’ll use a writing tool for 3+ years, yes. At $399, you break even vs Grammarly’s annual rate in 2.8 years. Every year after that is “free.”
Which catches more errors?
For basic grammar and spelling, they’re comparable. Grammarly is slightly better at real-time suggestions in casual writing. ProWritingAid is better at catching style issues in longer documents.
Does ProWritingAid have a browser extension?
Yes, but it’s less polished than Grammarly’s. It works in most text fields but can be slow with large blocks of text.
Is Grammarly worth 3x the long-term cost of ProWritingAid?
Depends on how you value convenience. Grammarly’s always-on, everywhere approach saves time daily. ProWritingAid’s deeper analysis saves time during editing sessions. If you write mostly in a dedicated app (Word, Scrivener, Google Docs), ProWritingAid’s depth is more valuable. If you write across dozens of web apps, Grammarly’s integration is more valuable.
Pricing data sourced from grammarly.com/plans and prowritingaid.com/pricing on March 18, 2026. ProWritingAid lifetime deals may have limited availability. Verify current pricing.
