Grammarly is not an AI writing tool — it's the editing layer that makes AI writing better. With 30 million daily active users and integrations across every platform you write in, it's the most popular writing assistant on the planet. But in 2026, with AI writing tools producing increasingly polished output, does Grammarly Premium still earn its $12/mo price tag?
This review covers Free vs Premium vs Business, tests GrammarlyGO's AI features, and shows how Grammarly fits into an AI-powered content workflow.
Anyone who writes professionally. Grammarly is unique — it's not a replacement for AI writing tools like Writesonic or Jasper, but the perfect complement. AI writes the draft, Grammarly polishes it. Together they form a complete content workflow.
Key insight: The annual Premium plan ($12/mo) is the sweet spot. Monthly Premium at $30/mo is hard to justify — always choose annual billing. Business is worth it for teams of 5+.
I tested Grammarly Free and Premium across 10,000 words of mixed content — blog posts, emails, social media, and product descriptions.
| Error Type | Free Catches | Premium Catches |
|---|---|---|
| Spelling errors | ✅ ~95% | ✅ ~97% |
| Basic grammar | ✅ ~80% | ✅ ~92% |
| Punctuation | ✅ ~75% | ✅ ~90% |
| Wordy sentences | ❌ | ✅ Strong |
| Passive voice | ⚠️ Basic | ✅ Detailed |
| Tone accuracy | ⚠️ Labels only | ✅ With fixes |
| Plagiarism | ❌ | ✅ 16B+ pages |
| Overall catch rate | ~70% | ~90% |
Bottom line: Free catches embarrassing errors well. Premium catches the subtle ones — and the clarity/rewrite suggestions save significant editing time.
GrammarlyGO is Grammarly's built-in AI assistant (powered by GPT models). It can draft, rewrite, and adjust tone. In my testing:
GrammarlyGO is best thought of as a polish layer, not a primary writing tool. Write your draft in Writesonic or Claude, then use GrammarlyGO for the final polish.
This is where Grammarly shines. Here's the optimal workflow I use:
Writesonic ($20/mo) + Grammarly Premium ($12/mo) = $28/mo total
This combination covers AI writing + professional editing for less than Jasper's entry price alone. Best value for small businesses and solo creators.
Grammarly isn't competing with AI writing tools — it completes them. For the $12/mo annual Premium plan, you get a writing assistant that catches what AI writing tools miss and polishes what they produce.
Best plan: Premium annual at ~$12/mo. Start with Free — if you find yourself wanting better clarity suggestions, upgrade.
Writesonic ($20/mo) for AI writing + Grammarly Premium ($12/mo) for polish
At $12/mo (annual), yes for professionals writing 5,000+ words/week. The clarity suggestions, plagiarism checker, and full-sentence rewrites save significant editing time.
No. Grammarly is an editing assistant. It pairs best with tools like Writesonic or Claude for a complete workflow.
Yes for casual use. Free catches ~70% of errors. Premium is needed for clarity rewrites, tone adjustments, and plagiarism checking.
No. For AI detection, use Originality.ai or GPTZero. Grammarly checks grammar regardless of how the text was created.