Tool profile
Grammarly: what it is, what it costs, where it breaks
Grammarly is an AI writing assistant made by Superhuman Platform Inc. (formerly Grammarly, Inc.) that checks grammar, tone and clarity, rewrites sentences and detects plagiarism and AI-generated text inside browsers, desktop apps, Microsoft Office and Google Docs. It is sold as a free tier, a Pro subscription and a sales-quoted Enterprise plan.
What to know first
Grammarly works as a layer on top of the apps where text is already written, not as a separate drafting studio. The plans page in October 2026 showed Free at 0 euros with 100 AI prompts a month, Pro at 12 euros with 2,000 prompts per member a month, and Enterprise by contacting sales with unlimited prompts. The page did not state the billing period for Pro, so confirm it at checkout.
Grammarly at a glance
| Maker | Superhuman Platform Inc. (formerly Grammarly, Inc.), United States |
|---|---|
| Free plan | Yes |
| Entry price | Pro at 12 euros per member per month |
| API access | No |
| Category | Best AI Writing Tools in 2026, rank 1 of 10 |
| Website | grammarly.com |
Who Grammarly is best for
Office workers writing in many apps
Desktop, browser, Microsoft Office and Google Docs versions mean the same suggestions follow a person from a support ticket to a slide deck without copying text between tools.
Students and researchers
Pro lists citation consistency, plagiarism detection and AI-text detection, which cover the checks a thesis or paper usually needs before submission.
Non-native English writers
Pro adds fluent English writing and full-sentence rewrites, which go beyond the spelling and grammar correction that the Free plan stops at.
Companies standardizing communication
Enterprise adds SAML single sign-on, SCIM, audit logs API, unlimited style guides and brand tones, for admins who need central control over how staff write.
Grammarly plans and pricing
| Plan | Price | What it includes |
|---|---|---|
| Free | 0 euros | 100 AI prompts a month, spelling and grammar correction, tone visibility and help center support. Tone adjustment, rewrites and detection tools are not included. |
| Pro | 12 euros (billing period not stated on the page) | 2,000 prompts per member a month, full-sentence rewrites, tone adjustment, plagiarism and AI-text detection, citation consistency, 1 style guide, 1 brand tone, 2 user groups and priority support. |
| Enterprise | Custom, contact sales | Unlimited prompts per member, proactive AI, SAML SSO, SCIM, data loss prevention, BYOK encryption, unlimited style guides and brand tones, audit logs API and dedicated support. |
Prices as of October 2026; vendors change plans often, so confirm on the vendor's pricing page.
What Grammarly does
- Inline correction
- Spelling, grammar and tone suggestions appear as you type in the apps Grammarly is installed in. This is the part available on the Free plan, and it is what most users mean when they say they use Grammarly.
- Rewrites and tone adjustment
- Pro rewrites full sentences and shifts tone, for example to sound more formal or friendlier. Each request that calls the generative assistant counts against the monthly prompt allowance shown on the plan.
- Detection and citation tools
- Plagiarism detection and AI-text detection are listed on Pro, along with citation consistency. The homepage also names AI agents such as an AI Detector, Citation Finder, AI Grader and Reader Reactions.
- Style guides and brand tone
- Pro allows one style guide and one brand tone, plus snippets and knowledge sharing. Enterprise lifts those counts to unlimited, which matters for companies with separate product lines or regional teams.
- Admin and analytics
- Pro includes team analytics and account roles and permissions. Enterprise adds an ROI report, an Effective Communication Score, session timeout settings and custom roles for larger rollouts.
How Grammarly handles your data
Grammarly's trust center says it does not sell or monetize user and customer content, and that its algorithms analyze text, writing behavior and usage data to produce suggestions. Its FAQ says users can opt out of letting Grammarly use their content to train models, through the Product Improvement and Training setting in account settings. Documents are stored until the user deletes them or the account. The page says Grammarly maintains annual security certifications and links a blog post about its SOC 2 report and ISO certifications, but it does not name the ISO standards, state encryption details or address data location. Request the full security documentation first.
Where Grammarly falls short in practice
- Training opt-out is a setting, not the default. The FAQ describes training on content as something a user can opt out of. A company that wants this off for every employee needs to check how the setting is enforced across accounts before rollout.
- Prompt allowances shape heavy use. Free stops at 100 AI prompts a month and Pro at 2,000 per member. A person who drafts with the assistant all day, rather than polishing text, should watch how fast that allowance is used.
- Brand controls are capped below Enterprise. Pro permits one style guide and one brand tone. An agency writing for several clients, each needing its own voice, runs into that ceiling and has to talk to sales.
- Pricing page leaves gaps. The plans page gave no billing period for the 12 euro Pro price and no price for Enterprise. Annual versus monthly cost, and any seat minimum, have to be confirmed before budgeting.
Works with
Alternatives to Grammarly
Grammarly: common questions
How many AI prompts does Grammarly give on each plan?
As of October 2026, the plans page lists 100 prompts a month on Free, 2,000 prompts per member a month on Pro, and unlimited prompts per member on Enterprise. Basic spelling and grammar correction is listed separately on Free, so the prompt count matters mainly for rewrites and generated text.
Can I stop Grammarly from using my writing to train its models?
Yes, according to the FAQ on Grammarly's trust center. The setting is called Product Improvement and Training and sits in account settings. The same page says Grammarly does not sell user content. It describes training as something you opt out of, so check the setting after creating an account.
Does Grammarly Pro include plagiarism and AI detection?
Yes. The plans page lists plagiarism detection and AI-text detection on Pro, and the Free plan explicitly lacks them. Citation consistency is also a Pro item. The page does not describe how detection accuracy is measured, so treat results as a signal rather than proof.
Which apps does Grammarly work in?
Grammarly's site lists a desktop app for Windows and Mac, a browser extension for Chrome, Safari, Firefox and Edge, add-ins for Microsoft Office and Google Docs, and apps for iPhone, iPad and Android. It also shows suggestions inside a Zendesk text box in a demo, without listing Zendesk as a formal integration.
Is Grammarly the right choice for a company with several brand voices?
Usually only on Enterprise. Pro includes one style guide and one brand tone, while Enterprise lists unlimited style guides and brand tones plus SSO, SCIM and audit logs. A company needing many distinct voices should price Enterprise or compare it with tools built around stored voices.