Grammarly review: a near-perfect checker with a pushy AI

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Is Grammarly worth it?

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Yes, as a free proofreader: Grammarly flagged all 23 problems I planted in two practice paragraphs and raised nothing on a clean one. Its AI layer was less trustworthy in my test, because one rewrite added a claim I never wrote and another dropped a fact while saying it had kept them all. Use the free plan for proofreading, and pay $12 a month, billed annually, only if you need plagiarism and AI-detection checks.

What does Grammarly do?

Grammarly reads what you write and underlines what it thinks is wrong or weak. Red underlines are mostly correctness: spelling, grammar, punctuation. Blue ones are clarity. Each underline has a card in a side panel with a short label (“Use the right word”, “Correct article usage”) and a one-click fix.

That checker now sits inside a bigger product. New documents open in Grammarly Docs, a browser editor, with a rail of 13 tools down the right edge: AI Chat, the proofreader, AI Grader, Citation Finder, AI Detector, AI Rewriter, Humanizer, Paraphraser, Plagiarism Checker, Reader Reactions, Authorship, Resume Builder and Word Count. Grammarly calls most of these agents. The same checker also runs in a browser extension, desktop apps, Word on Windows, Google Docs and a mobile keyboard, according to Grammarly’s site.

The company behind it changed too. Grammarly agreed to buy the Superhuman email app in 2025 and, on 29 October 2025, renamed itself Superhuman. The Grammarly product kept its name. You will see Superhuman on the terms, the privacy policy and the Enterprise plan, but the editor still says Grammarly.

What changed in 2025 and 2026

If you last used Grammarly a couple of years ago, four things are different.

• Premium became Pro. Grammarly’s support page on the switch says it began moving Premium users to Pro in March 2025 at the same billing amount. Pro raised the monthly AI prompt allowance from 1,000 to 2,000, and the old Business plan’s team features folded into it.
• The editor became Docs. The web editor is now Grammarly Docs, an “AI-native document editor” according to Grammarly’s Docs page, with the agents built in. The same page says real-time collaboration is still in development.
• Expert Review came and went. An agent that gave feedback in the style of named real writers launched in 2025 and was pulled in March 2026 amid backlash and a lawsuit, covered under The bad below.
• The Mac Word add-in is gone. A Grammarly support article says Grammarly for Microsoft Word on Mac has been discontinued. Word on Windows still works.

If a guide still describes Premium or Business plans, it predates the switch to Pro or was never updated, so check its date.

How I tested it

On 22 October 2026 I used a free Grammarly account in the Docs editor. I wrote three practice paragraphs for the test, each with an answer key written before I pasted it:

• Paragraph one, a 101-word product update with 14 planted problems: 12 clear errors (“its been”, “effected”, “Their is”, “a odd”, “Me and Sam”, “to slow”, “alot”) and two judgement calls, a British-style “team have” and a comma splice.
• Paragraph two, a clean 77-word control with deliberate style choices: sentence fragments, a semicolon, “whom” and a sentence starting with “And”.
• Paragraph three, 74 words with nine subtler mistakes: a dangling modifier, “principle” for “principal”, “who’s” for “whose”, “between you and I”, “could of”, “less” for “fewer”, “irregardless”, “effects” for “affects” and “each of the designers have”.

Planted errors make the score checkable. Pasting in a real draft tells you what a tool flagged, but not what it missed, because nobody wrote down the mistakes first. With a key, every miss and every false alarm is countable.

I also ran the free AI tools on the first paragraph and spent one of the month’s 100 AI prompts on a rewrite. I did not test Pro, the browser extension or the mobile apps.

The proofreader

The core feature did its job. Paragraph one came back with a writing-quality score of 48 and 18 suggestions, 16 for grammar and 2 for clarity. All 14 planted problems were among them, including both judgement calls, and the extras were fair: a missing comma after “Overall”, two clarity flags and two offers to rewrite whole sentences.

Paragraph three was the harder test, and it caught all nine there too, scoring the paragraph 57. The dangling modifier, “Walking into the office, the printer was already jammed”, is the kind of mistake simple checkers miss, and Grammarly flagged it with a fix starting “When I walked”, offered as a Pro suggestion free sample.

The clean paragraph is the result I trust most. It scored 100 with zero suggestions. Grammarly left the fragments, the semicolon, “whom” and the sentence starting with “And” alone, which means it was not just underlining anything unusual.

The AI tools around it

The agents are where Grammarly is trying to grow, and on a free account more of them work than I expected. AI Grader predicted a grade of 55 out of 100 for paragraph one, but its feedback was about content and organisation, not about the 14 errors sitting in the text.

Reader Reactions was the most useful of the extras. Set to a product development team, it summarised the three points that reader would remember and the four questions they would ask, such as whether the lost meeting notes could be recovered. Every point matched the text.

AI Chat took a plain request and proposed its answer as tracked changes in the document, which makes it easy to see what moved. The Strengthen writing tab does the same at paragraph level, offering whole rewrites such as “Tighten sentence flow” as free samples.

The Paraphraser and the Humanizer both opened on the free account. The Paraphraser offers six styles (Humanize, Academic, Professional, Streamlined, Creative and Simple) and lets you describe your own; the Humanizer has five preset voices, from The Naturalist to The Scholar. Grammarly also runs a free humanizer page without a sign-in, which says the tool “is not intended to bypass AI detectors”.

How much does Grammarly cost?

Grammarly’s plans page shows three self-serve tiers and an Enterprise plan sold through sales.

Plan	Price (USD)	What you get
Free (Basic when signed in)	$0	Grammar, spelling and punctuation checks, tone detection, 100 AI prompts a month, most Docs agents
Pro	$12 a month billed annually ($144 a year), or $30 billed monthly	Full-sentence rewrites, tone adjustment, fluency, plagiarism and AI-text detection, citation formatting, 2,000 AI prompts a month
Pro for Teams	$12 per member a month, minimum 3 seats	Pro billed per member for teams, with a shared style guide, brand tones and team analytics
Enterprise	Contact sales	Unlimited prompts, SSO, data loss prevention, BYOK encryption, dedicated support

The headline price hides the biggest cost: paying monthly. Grammarly’s Pro page lists $12 a month billed annually and $30 when billed monthly, so a month-to-month subscriber pays two and a half times the annual rate. Signed in, the plans page showed a free trial with an email reminder two days before it ends, but no trial length.

Refunds are the second catch. Grammarly’s refund page says you can cancel at any time but “refunds are issued only if required by law”, and the terms list payments as non-refundable. If you pick annual by mistake, you have paid for a year. Our Grammarly pricing guide covers the quarterly plan, the student discount and the Superhuman bundle.

Is Pro worth the upgrade?

For proofreading alone, no. Every planted error was flagged on the free plan, and the Pro rewrites I saw arrived as free samples. What Pro sells is the layer on top: plagiarism and AI-text checks, rewriting whole sentences whenever you ask, tone adjustment, and 2,000 AI prompts a month instead of 100.

That makes the decision fairly simple. If a teacher or client checks your work for plagiarism, Pro saves you a separate tool. If you lean on AI rewrites every day, 100 prompts a month will run out and Pro is the fix. If you mostly want typos caught before you hit send, keep the money.

One oddity is worth checking before you buy. Superhuman’s own plans page lists its Pro suite, which includes Grammarly, at $12 a month billed annually and $15 billed monthly, half Grammarly’s monthly price. I did not go to checkout, so I cannot say whether the two Pro plans are identical, and cancelling Grammarly through your account cancels across the Superhuman suite if you hold a Superhuman subscription.

Who is Grammarly for?

• Anyone who writes in English and wants a safety net. The free plan caught every planted error in my test, which is most of what most people need.
• Students who must check for plagiarism. The Plagiarism Checker and the AI Detector agent are Pro features, and AI Grader is free for a first look at an essay.
• Non-native English writers. Fluency suggestions are in Pro, and the free checker labels every fix (“Use the right word”, “Correct article usage”), which helps you learn the pattern.
• People who write email and documents all day. The checker runs in the browser, Word on Windows and Google Docs, so one free account covers most of a working day.
• Small teams who want one house style. Pro for Teams bills Pro per member from 3 seats and includes a shared style guide and brand tones.
• Not for writers with a deliberate voice who want to be left alone. On r/Grammarly, an April 2026 post asks Grammarly to stop pushing “clarity and flow” edits onto fiction, and the AI layer in my test was quick to rewrite whole paragraphs.

The good

It caught every planted error, free

Twenty-three problems went in and twenty-three were flagged, on a free account. That included the hard ones, a dangling modifier and “between you and I”, as well as the typos. A proofreader is judged on what it misses, and in this test it missed nothing.

No false alarms on clean writing

A checker that underlines everything trains you to ignore it. Grammarly scored my clean paragraph 100 and raised no suggestions, leaving its fragments, semicolon and “whom” alone. That restraint matters as much as the catch rate.

The free plan is generous

Most of the Docs agents open without paying: AI Grader, Reader Reactions, Citation Finder, the Paraphraser with six styles and the Humanizer with five voices. Grammarly’s agents page says you can try most of them on the free plan, and in my account that held. The plans page adds 100 AI prompts a month.

Reader Reactions is a good second reader

Asking how a specific audience will read a draft is more useful than another grammar pass. Reader Reactions picked out the three points a product team would remember and four sharp questions, all grounded in the text. One was “Was there any way to recover the lost meeting notes, or were they permanently deleted?”, which is exactly what my imaginary manager would have asked. It is the agent I would keep using.

Authorship is free

Grammarly’s Authorship page says the feature is available on Free and Pro. It records what you typed, pasted or wrote with AI and produces a report you can choose to share, and your school cannot see it unless you do. I did not test it, but for a student worried about a false AI accusation, a free record of the writing process is a real feature.

It is everywhere you type

The browser extension is the product most people know. The Chrome Web Store listing shows 41,000,000 users and, per Grammarly, the checker also works in Word on Windows, Google Docs, desktop apps and a mobile keyboard. I tested the web editor only.

AI edits arrive as tracked changes

When AI Chat or a rewrite card proposes an edit, Grammarly shows it as a diff, with deleted words struck through and new ones in green. That is how I spotted the dropped clause and the invented one below in seconds. A chatbot that hands back a clean block of new text would have hidden both.

The bad

The AI rewrites change your meaning

This is the one that matters. In the Strengthen writing tab, the “Clarify key impact” card offered a rewrite titled “Link each issue to its effect so the stakes are clearer”. It changed my sentence about slow search to end “which made finding notes harder”, and swapped “effected” for the stronger “disrupted”. I never wrote that closing clause. It is a plausible claim, but it was not mine, and accepting it puts words in my mouth.

AI Chat did the opposite. I asked it to rewrite the paragraph as a status update and to “keep every fact and do not add new ones”. It fixed every error but cut “it’s been a mixed experience”, then replied that “All facts are preserved”. Read every AI rewrite before you accept it.

The free editor is a sales floor

A “Try Pro for $0” button sat at the top of the editor on every page I opened, and locked agents showed their own “Try for $0”. Several suggestions arrive with a “Pro suggestion · Free sample” badge, and the Strengthen writing cards say “Plus suggestion · Free sample”, a plan name that does not appear on the plans page. The samples are good, which is the point: they show you what you are missing.

The naming adds to the confusion: the free plan is called Basic on the plans page I saw signed in and Free on the public one. Grammarly’s editor is called Docs, while Coda’s product, owned by the same company, is now Superhuman Docs. None of this breaks anything, but it makes the plans page harder to read than it should be.

It sells AI detection and AI disguise side by side

On my free account the AI Detector panel was locked behind “Try for $0”. Directly below it, a card headed “Before you turn it in” promoted the AI Rewriter: “Swap out phrases that may appear to be AI-generated”. Grammarly sells the test and a way around it in one panel, worded for students handing in work.

The detector itself promises more than detectors deliver. Grammarly’s AI detector page claims 99% detection accuracy and a first place on the RAID benchmark, and further down says “No AI detector is 100% accurate.” Users report misses in both directions. In a September 2026 r/Grammarly post, a writer says a paragraph they wrote by hand was flagged as AI; in a June 2026 post, another user says text pasted straight from Gemini scored 0%. I did not test the detector here, and I would not treat any detector’s score as proof either way.

Monthly billing is expensive and refunds are rare

At $30 a month, the monthly plan costs $360 over a year against $144 billed annually, a $216 difference for the same features. Monthly only makes sense if you need Pro for a single deadline and will cancel straight after. Grammarly refunds only where the law requires it, and billing mix-ups show up on Reddit: in an October 2026 r/Grammarly post, a user who expected monthly billing says they were charged $165 for a year and offered back $114.

Your writing trains its AI by default

Grammarly’s training-control page says “Product Improvement and Training is on for individual users by default”. That covers Free and single-user Pro. You can turn it off in your account settings, and Enterprise and Education accounts start with it off, but most individual users will never look.

It is one switch. On a Free account the switch is under account.grammarly.com/security/privacy, according to the same support page; single-user Pro accounts find it in the admin data settings. Grammarly’s privacy page adds that it never sells the content you upload or lets third parties use it to train their models, so the default trains Grammarly’s own AI, not someone else’s. Companies with stricter rules get more control on Enterprise: the plans page lists data loss prevention, confidential mode and bring-your-own-key encryption there.

Ordinary users rate it much lower than businesses

On G2, a business-software review site, Grammarly scores 4.7 from 14,084 reviews. On Trustpilot, where anyone can post, it scores 3.1 from 10,482. The Chrome Web Store sits between them at 3.9. My reading is that the gap is about who is rating: a company buying seats judges the admin tools and the catch rate, while an individual paying their own money also judges the upsells, the billing and the AI suggestions they never asked for.

Trust took a hit this year too. Grammarly’s Expert Review agent, which gave AI feedback in the style of named real writers, was pulled in March 2026, the same week a writer sued over it for using authors’ names without consent.

The AI Grader ignores the errors

AI Grader gave paragraph one a predicted 55 out of 100 and talked only about structure and detail. It did not mention any of the 14 errors in the text. A student reading the grade alone would not know their essay needed proofreading first.

Alternatives worth considering

If you decide Grammarly is not for you, these are the places to look.

QuillBot is the pick if you mainly want to reword text rather than check it. Its free plan paraphrases up to 100 words at a time in two modes and fixes basic grammar errors, and Premium opens unlimited modes, the full AI detector and a plagiarism check. Try QuillBot.

ChatGPT suits people who would rather describe the edit they want than accept suggestions one by one. It will proofread, rewrite and explain, but it has no live underlines as you type, so it works better on a finished draft. The trade-off cuts both ways: you lose the one-click fixes, but you also control exactly how much it is allowed to change, which is the problem I had with Grammarly’s rewrites. Our ChatGPT review covers its plans and limits, and if you want a different chatbot for the job, see our Claude review or our best AI assistant roundup.

Final word

Grammarly’s checker is still the reason to use it, and the free plan gives you all of it: 23 planted problems found, nothing invented on clean prose. The AI built around it is useful in places, Reader Reactions most of all, but it rewrites too freely to accept without reading. It stays our best pick for writing, because its free checker did everything I asked of it; the 4.3 is about the AI layer rewriting meaning, not about a rival doing the job better. Start free, turn off training in your settings, and only pay, annually, if plagiarism or AI-detection checks are part of your job.