Grammarly

Rating reflects Grammarly's documented plans and capabilities as of September 2026 plus our own sessions. Some vendor links on this site are affiliate links; they never affect a rating. See our disclosure and method.

What it does

Grammarly reads what you type and suggests fixes in place: spelling, grammar, punctuation, clarity, tone and, on paid plans, whole-sentence rewrites. It runs as a browser extension and a desktop app, so the same suggestions appear in Gmail, Google Docs, Word, Slack, Outlook and, by Grammarly's count, over a million other apps. That reach is the product. ChatGPT and Claude will write better prose on request, but you have to bring the text to them. Grammarly comes to the text.

Since 2025 it has also been a set of agents. Inside Grammarly's own docs editor you can call a Proofreader, a Citation Finder, a Reader Reactions agent that predicts how an audience will respond, an AI Grader, a paraphraser, and plagiarism and AI-text detectors. In June 2026 the Authorship feature started recording which of those agents touched a document, so a report can say a citation was found by the Citation Finder and a paragraph was written by the user rather than lumping every kind of help into one AI category.

Then there is the corporate story, which matters because it changed the plans. Grammarly bought the Superhuman email client in July 2025, renamed the whole company Superhuman on October 29, 2025, bought the spreadsheet startup Rows in February 2026, and folded Coda into Superhuman Docs on July 8, 2026. The writing product is still called Grammarly, but its Enterprise tier is now sold as part of Superhuman Go, an assistant that reads whatever is on your screen and connects to Gmail, Outlook, Slack, Jira, Salesforce and the rest. Go 1.0 shipped on August 12, 2026 with a no-code builder for custom agents, an Email Assistant that sorts your inbox and drafts replies in your voice, a Knowledge Checker that verifies claims against company data, and a Go app for Mac, Windows and iOS.

Where it wins

• It is everywhere. No other card in the diamonds suit follows you into every text box. The value is not any single suggestion; it is the thousand small catches a week that you never had to ask for.
• The free tier is real. Grammar, spelling, punctuation and basic tone detection are free, with 100 AI prompts a month for rewrites. Two independent 2026 pricing guides we read both concluded that casual writers and students can stay on Free indefinitely.
• Authorship. For students and anyone who might be accused of using AI, a shareable report that shows text was typed over three sessions, with two pasted quotes and one AI-rewritten sentence, is more useful than any detector. Tech & Learning's April 2026 retest found it correctly identified typed, pasted and AI-generated passages. It reached Blackboard in August 2026.
• Team features at the Pro price. Pro includes one style guide, one brand tone, two user groups, snippets and team analytics, and the Pro page says a team account can run to 149 people. That used to be the separate Business plan.
• Agents that stay in your lane. Reader Reactions and Expert Review give feedback on a draft without rewriting it for you. If you want to keep your own voice, that is the right design.

Where it loses

• The headline price is the annual price. The plans page shows Pro at $12. That is $144 paid up front. Month to month, Pro is $30, and a quarterly option runs $60 for three months. Two and a half times the sticker is the biggest billing surprise in this suit.
• Prompt caps. Free is 100 generative prompts a month and Pro is 2,000 per member. Heavy rewriting can hit the free cap in a week. Unlimited prompts are Enterprise only.
• Privacy record. Model training is opt-out rather than opt-in on every self-serve plan. In March 2026 Superhuman enabled a human Expert Review feature by default in its email client and, after a backlash, offered an opt-out by email rather than turning it off. The Go data FAQ is clear and well written, but the pattern has been to ask forgiveness.
• It is not a chatbot. Grammarly's generative writing is fine for a first draft of an email. For anything long, researched or creative, Claude or ChatGPT will do better, and the free tiers of both are more generous than 100 prompts.
• Suite creep. The upgrade path above Pro is now a $33 a month Superhuman Business seat that bundles Mail, Docs and Go. If all you wanted was a better grammar checker, that is $21 a month for products you may never open.

Plans and pricing, September 2026

Existing Premium subscribers who switch to Pro get a prorated refund on the old plan. Grammarly for Education is sold separately to institutions, and Authorship can be switched on or off for a whole team by a Business admin.

Score breakdown

Alternatives

• Claude if you want a stronger writer for long documents and are happy to paste text into a chat.
• Notion AI if your writing lives in Notion already and you want agents that touch your workspace, not just your sentences.
• ChatGPT if you mostly need drafts generated rather than checked, and want a free tier with no prompt cap.

Quick answers

Is Grammarly free?

Yes. The Free plan checks spelling, grammar and basic tone everywhere you type and includes 100 AI prompts a month. Pro, which adds full-sentence rewrites, tone adjustment, plagiarism and AI detection and 2,000 prompts a month, is $12 a member a month when you pay $144 for a year up front, or $30 a month billed monthly.

What is Grammarly Authorship?

A record of how a document was written. With tracking on in Google Docs, Word or Grammarly's own docs, it categorizes text as typed, pasted from a website, pasted from an unknown source, or generated by AI, and since June 2026 it names which writing agent helped. You choose whether to share the report. It is proof of process, not proof that the argument is right.

Does Grammarly train on my writing?

It can. Grammarly and Superhuman Go users have a training preference in account settings; it is opt-out on Free, Pro and Business and off by default on Enterprise. Content is never used to train third-party models. Check the setting the day you sign up: in March 2026 the company had to add opt-outs after enabling a human Expert Review feature by default in Superhuman Mail.

More cards

• 
  Tool cards

  Notion AI

  Agents inside the workspace, and what the credits cost.

• 
  Tool cards

  Claude

  The writer's model, rated and priced.

• 
  Prompt packs

  Email prompts that get replies

  Copy-paste prompts for the inbox, with copy buttons.