Grammarly Free costs nothing and covers spelling and grammar corrections, tone detection and 100 AI prompts a month. Pro costs $144 a year billed annually, which Grammarly advertises as $12 a month, or $30 billed month to month (as of Nov 9, 2026).
What Pro adds
Pro adds full-sentence rewrites, tone adjustment, fluency suggestions, inclusive-language and citation checks, plagiarism and AI-text detection, priority support, and 2,000 AI prompts per member a month. Enterprise is sold through sales and has unlimited prompts.
Monthly, quarterly or yearly
Grammarly bills Pro monthly ($30), quarterly ($60) or yearly ($144), in US dollars by default. Inside the iPhone app (US App Store, as of Nov 9, 2026), the Monthly, Quarterly and Annual plans are $29.99, $59.99 and $139.99, and there are Mobile Only plans at $17.99 a month or $83.99 a year.
The Pro trial
The plans page shows "Try for $0.00" and "$0 payment today" on Pro, with the note: "Email reminder 2 days before trial ends." Grammarly's help center says you aren't charged before a seven-day trial ends; a pending charge during it is a temporary card verification.
Old Premium subscribers
The plans-page FAQ says that if you have a Premium subscription and switch to Pro, Premium is cancelled and you get a refund prorated to the rest of the term. Pro includes Premium's writing features, such as tone suggestions and full-sentence rewrites, plus team features that used to be in the Business plan.
Sources
- Grammarly — Prices and Plans (checked Nov 9, 2026)
- Grammarly Support — How much does Grammarly Pro cost? (checked Nov 9, 2026)
- Grammarly Support — free trial billing (checked Nov 9, 2026)
- Apple App Store (US) — Grammarly: AI Keyboard & Voice (checked Nov 9, 2026)