Grammarly

What it actually does

Grammarly reads what you type and flags grammar and spelling errors, then adds a tone read on top. It runs in the browser, in a desktop app, and on a mobile keyboard, so it works in almost any text field you land in. That ubiquity is the actual product. Most people keep it installed for years without thinking about it.

The free tier covers grammar, spelling and the tone detector, and it is genuinely useful on its own. Premium layers on clarity rewrites, vocabulary suggestions, a plagiarism checker and the generative features sold as GrammarlyGO. Business adds team style guides and analytics. One thing buyers should know: the company renamed itself Superhuman in October 2025, after buying the Superhuman email client in July 2025 and Coda in December 2024. The proofreader keeps the Grammarly name for now, but the scope is moving toward an agentic assistant (Superhuman Go) that connects to Gmail, Drive, Calendar and Jira. That is a different data-access profile than the spellchecker people originally paid for.

What it costs

Premium is $12 a month. Business is $15 per seat per month. The free plan is not a crippled demo, and for a lot of people it is the correct answer.

The catch is the renewal. Billing is the single loudest theme in consumer reviews: users report auto-renewal charges landing with no advance notice, and several say the renewal price was roughly double what they paid the previous period. Grammarly's own support page states that refunds are issued only where required by law, which makes a refund a favor rather than a right. Multiple user accounts say support does refund on request through a ticket, but inconsistently. Treat the subscription like a gym membership and put the renewal date in your calendar.

Where it falls down

The most serious complaint is not about writing quality. Users report canceling, or seeing their account show the free plan, and still being charged for Premium. The refund form's canned reasons often do not match the situation people are actually in, which pushes them into a support queue with no guaranteed outcome.

The desktop app draws steady complaints about lag and crashes, with users copying text out of it to get work done. The AI writing output gets described as machine-sounding, and the suggestions as cookie-cutter, often swapping one common word for another, with no way to teach it a brand voice. The plagiarism checker misses paywalled and offline academic sources, so students should not treat it as the only check before submitting. Professionals also raise privacy unease about an always-on extension that reads everything typed, and the new app connections widen that surface.

The numbers show the split cleanly. G2 sits at 4.7 across 14,073 reviews and Capterra at 4.7 across 7,223 for Grammarly Business, while Trustpilot sits at 3.1 across 10,463. Business buyers rate the tool. Consumers rate the billing.

Who should buy it

Buy it if you write for a living and want fewer errors with near-zero friction. It remains the most accurate, lowest-effort checker we know of, and the 4.0 reflects that. The free plan is the right starting point, and Premium earns its $12 mainly through the clarity rewrites.

Do not buy it expecting a ghostwriter. If you need copy in a specific brand voice, this is not the tool, and a general assistant you can prompt directly will do better for less. Students who need a defensible plagiarism check should use whatever their institution provides instead, because the paywalled-source gap is real. Anyone handling client-confidential text in regulated work should think hard before granting an always-on assistant access to mail and files. And if you are bad at tracking subscriptions, buy the annual plan deliberately or stay on free, because the renewal is where this product loses people.