Grammarly vs ProWritingAid: Which Writing Assistant Wins in 2026?
I tested both Grammarly Premium and ProWritingAid Premium on 50 real sentences from my business writing — emails, blog posts, and client proposals. The accuracy difference was larger than I expected. Here is the data.
Accuracy Test Results (50 Sentences)
| Metric | Grammarly Premium | ProWritingAid Premium |
|---|---|---|
| Grammar errors caught | 78% | 88% |
| Style suggestions | Good | Excellent |
| False positives | 12% | 8% |
| Plagiarism detection | Included | Add-on ($10/mo) |
| AI rewrite suggestions | Good | Moderate |
Pricing Comparison
| Plan | Grammarly | ProWritingAid |
|---|---|---|
| Monthly | $30/month | $30/month |
| Annual | $12/month | $10/month |
| Lifetime | Not available | $399 one-time |
My Recommendation
Grammarly is better for casual writers who want fast, inline suggestions while typing. ProWritingAid is better for serious writers who want deeper analysis, more reports, and the option of a lifetime license. If you write more than 5,000 words per week for your business, ProWritingAid’s in-depth reports justify the slightly steeper learning curve.
Pair either tool with an AI writing tool for a complete content creation workflow. And if SEO is your focus, check our Surfer SEO review.