Grammarly Premium costs $12–$30/month depending on billing. We break down what the free tier actually catches, what Premium adds, and who genuinely benefits from the upgrade.
The free tier catches most errors for casual writers. Premium's value is in tone, clarity, and style suggestions - genuinely useful for anyone whose writing directly impacts their professional reputation.
Grammarly's free tier is legitimately useful. It catches spelling errors, basic grammar mistakes, punctuation issues, and some sentence structure problems. For most casual writing - personal emails, social posts, quick messages - it's sufficient.
| Feature | Free | Premium |
|---|---|---|
| Spelling & grammar | ✓ | ✓ |
| Basic punctuation | ✓ | ✓ |
| Tone detection | Limited | Full - 40+ tones detected |
| Clarity & conciseness suggestions | ✗ | ✓ |
| Word choice / vocabulary | ✗ | ✓ |
| Plagiarism detection | ✗ | ✓ |
| Full-document rewrites (AI) | Limited | Unlimited |
| Generative AI (GrammarlyGO) | 100 prompts/mo | 1,000 prompts/mo |
| Style guide enforcement | ✗ | ✓ |
The gap that matters most for professionals: Premium's clarity and conciseness suggestions. These go beyond grammar - they flag sentences that are technically correct but hard to read, suggest more precise word choices, and catch passive voice, wordiness, and hedging language that weakens writing. This is the difference between a grammar checker and a writing coach.
| Plan | Monthly billed | Annual billed |
|---|---|---|
| Free | $0 | $0 |
| Premium | $30/mo | $12/mo ($144/yr) |
| Business (per member) | $25/mo | $15/mo ($180/yr) |
The $30/month rate for month-to-month Premium is genuinely expensive. The annual plan at $12/month is the price that makes sense - $30/month is hard to justify for most users. If you're paying $30/month, switching to annual billing saves $216/year for the exact same product.
New subscribers can try all Premium features free. The upgrade is instant - cancel anytime if it doesn't click.
Microsoft Editor (free with Microsoft 365 or as a free browser extension) covers grammar, spelling, clarity suggestions, and tone detection - covering roughly 70% of what Grammarly Premium does at no cost. If you're already paying for Microsoft 365, Editor is included.
ProWritingAid ($70/year) offers deeper writing analysis than Grammarly Premium - style reports, readability scores, overused words, sticky sentences - at roughly half the price. Better for long-form writers; less convenient for quick email use.
Hemingway Editor (free web, $19.99 desktop one-time) focuses specifically on readability - highlighting complex sentences, passive voice, and adverbs. Not a grammar checker but excellent as a complementary tool.
Worth it for: Professionals whose written communication reflects on their career - salespeople, marketers, executives, customer-facing roles. Anyone who writes long-form content (blog posts, reports, proposals). Students who want plagiarism detection and better grades on written work. Non-native English speakers who benefit from tone and naturalness suggestions beyond basic grammar.
Stick to free for: Personal use, casual emails, social media posts where grammar perfection is neither expected nor valued. The free tier catches the errors that matter most in low-stakes writing.
The honest test: Use Grammarly free for two weeks and track how often it flags something significant. If you're regularly accepting suggestions that improve your writing in meaningful ways, the Premium upgrade is worth $12/month. If it's mostly confirming your writing is fine, free is sufficient.
Grammarly Business ($15/member/month annually, 3-member minimum) adds style guide enforcement - you can define brand voice rules (e.g., "never use the word 'synergy'", "always use Oxford comma") that apply across an entire team. For content teams, marketing agencies, and companies with strong brand voice requirements, this pays for itself in consistency alone.
Grammarly reverts to the free tier on cancellation - your account and writing history stay. Here's the exact cancellation path.