AI writing assistant for grammar, style, and tone improvements.
Writing
Grammarly is the writing assistant that made grammar checking a habit — a background utility that has quietly been catching typos in your Gmail since 2015 and, in 2026, still runs the deepest grammar and style engine on the market. Founded in 2009 by Alex Shevchenko, Max Lytvyn, and Dmytro Lider, it grew from a browser extension for students into a full writing platform now used by more than 30 million daily active users and 70,000+ teams. What started as an underline-the-typo tool has become a suite that includes generative rewrites, tone detection, brand voice enforcement, plagiarism checking, AI writing assistance, and — since the acquisition of Coda AI in 2024 — a document-first collaboration surface aiming squarely at Notion and Google Docs.
What Grammarly actually does, cleanly stated, is read everything you type on a computer and offer suggestions. You install the browser extension, the native macOS or Windows app, or the Word and Docs add-ins, and Grammarly runs on every text field — Gmail, LinkedIn, Slack, Twitter/X, Google Docs, Word, Notion, Outlook, WhatsApp Web, your CRM, your ticket system. Real-time underlines flag grammar, spelling, punctuation, and style issues. Tone detection reads your draft and tells you what it currently sounds like. Full-document rewrites — reworked on generative models in 2024 — handle "make this shorter," "rewrite for a technical audience," and "match our brand voice" without leaving the page.
The one-line positioning: Grammarly is the writing tool you do not think about — it is just there when you type, catching the mistakes you would rather nobody see. It is not a replacement for ChatGPT on original drafts. It is a replacement for proofreading yourself, for the copy editor you cannot afford, and for the mental overhead of remembering that "affect" is the verb and "effect" is the noun.
Grammarly's product surface has widened past pure grammar into a full writing platform. The features that earn the subscription are the grammar engine, tone detection, and generative rewrites. Everything else is bundled value.
Real-time grammar, spelling, and punctuation. The pillar. Grammarly's engine catches issues that other checkers do not: subtle article errors ("a" vs "an" in unusual contexts), register mismatches ("we're gonna" in a legal doc), passive voice patterns, wordy constructions, hedging signals, and dangling modifiers. In head-to-head testing, Grammarly consistently catches issues that Microsoft Editor, LanguageTool, and even ChatGPT's inline rewrites miss.
Style and clarity suggestions. Beyond correctness — is the sentence tight, is the word choice right, is the paragraph well-organized. Grammarly flags redundancy, unclear antecedents, and needlessly complex constructions with actionable rewrites.
Tone detection. Grammarly reads your draft and tells you what it currently sounds like — "confident, informal, and slightly disappointed" is feedback you did not know you needed until you got it once. Adjust the tone dial and Grammarly suggests rewrites that shift the register without changing meaning.
Generative rewrites and AI writing. Rewrite the paragraph, expand the idea, shorten the passage, adjust for audience, or generate from a prompt. Grammarly's generative layer is built on frontier models and is context-aware of your document. Not as strong as ChatGPT on blank-page drafting, meaningfully better at "improve what I already wrote."
Brand voice and style guides (Business+). Teams define brand voice attributes, banned words, required capitalizations, and style rules. Grammarly enforces them on every writer, catches deviations, and shows analytics on which teammates write the cleanest copy. This is the feature that turns Grammarly from personal productivity into a team standard.
Snippets. Reusable text templates — your legal boilerplate, your sales sign-off, your product tagline — inserted with a keyboard shortcut across every app. Sounds small; teams that adopt snippets stop rewriting the same paragraphs weekly.
Plagiarism checker (Premium). Runs your document against a database of billions of web pages and academic sources. Genuinely useful for content marketers checking that a repurposed post is not too close to the original, and for students avoiding accidental cross-contamination.
Grammarly Coda (2024+). After acquiring Coda in 2024, Grammarly is building a doc-first workspace layer — collaborative documents with the writing assistant native to the surface. Still rolling out, still early, but the direction is Notion-adjacent.
Coverage. Chrome, Safari, Edge, Firefox extensions; native macOS and Windows apps; Word and Google Docs add-ins; iOS and Android keyboards; Outlook, Gmail, Slack integrations. If you type on a computer, Grammarly probably reads it.
Grammarly is freemium. The free tier is deeper than most freemium writing tools — basic grammar, spelling, punctuation, and tone detection on every text field — and Premium unlocks the generative and advanced features.
| Plan | Monthly | Annual (per month) | Quarterly (per month) |
|---|---|---|---|
| Free | $0 | — | — |
| Premium | $30 | $12 | $20 |
| Business | $25/user | $15/user | — |
| Enterprise | Custom | Custom | — |
Free at $0 is the tier the majority of Grammarly's 30 million daily users sit on. It covers grammar, spelling, punctuation, and a light tone read across every extension and app. For casual writers — emails, LinkedIn posts, Slack messages — this tier is enough.
Premium at $12/month annual (or $30 monthly, priced deliberately to push you to annual) unlocks the full grammar engine — advanced style suggestions, tone detection with rewrite options, full-document rewrites, generative writing, the plagiarism checker, and the snippet library. The value shows up on any document longer than a paragraph — the difference in rewrite quality between Free and Premium is not marginal.
Business at $15/user/month annual (minimum 3 seats) adds brand voice profiles, style guides, team analytics, admin controls, priority support, and SSO on the higher tier of Business. This is the plan for marketing teams, agencies, sales orgs, and content operations where consistency across writers matters.
Enterprise is custom-priced and adds SCIM provisioning, custom data handling, extended audit logging, and account management. For companies above roughly 200 seats with a compliance review process.
The honest read: Premium at $12/month annual is one of the highest-value subscriptions in the writing category for anyone who spends more than an hour a day writing on a computer. Business at $15/user is the tier that starts to earn on team consistency alone.
Pros
Cons
Solo founders, freelancers, and knowledge workers writing English content all day. Grammarly Premium at $12/month annual earns the subscription in the first week of real writing — the grammar engine plus tone detection plus generative rewrites cover most of the writing feedback loop.
Sales and customer success teams sending high volumes of email. Free covers the basics; Business unlocks brand voice, snippets for common responses, and analytics on team writing quality.
Marketing teams and content operations. Brand voice profiles enforce your company's tone across every writer, style guides catch banned words and required capitalizations, and team analytics show which teammates write clear copy vs. dense copy. Business at $15/user/month.
Non-native English writers and ESL students. Grammarly's engine catches issues Word and Docs miss — article usage, prepositional errors, register — and the rewrite suggestions are calibrated for clarity.
Consultants and analysts producing client-facing documents. Tone detection plus full-document rewrites turn "does this sound right" into a five-second check.
Anyone who has been embarrassed by a typo in a public post. The single moment where you did not notice "there" vs "their" in a LinkedIn post is a strong argument for $12/month.
Grammarly's real competition splits four ways: dedicated grammar tools, generative writing assistants, translation-first tools, and the "AI can do this for free now" pressure.
QuillBot — the paraphrasing and summarizing specialist. Grammarly polishes; QuillBot rewrites and summarizes. Different jobs, and most working writers eventually pay for both — total around $20/month. See our full comparison: QuillBot vs Grammarly vs DeepL.
DeepL and DeepL Write — the translation-first alternative. DeepL Write is a strong English and German polish tool. If your work crosses a language border, DeepL wins there and Grammarly still wins on grammar depth for English-only work.
ProWritingAid — the "long-form writer's" alternative. Deeper reports on pacing, sentence length variation, sticky sentences, and repetitive word usage. Weaker at real-time browser correction. Worth a look for novelists and long-form nonfiction writers.
LanguageTool — the open-source, privacy-first alternative. Free tier is more generous than Grammarly's; paid Premium is cheaper at around $60/year. Weaker on style and tone, weaker generative layer, but excellent on core grammar and available on-premises for regulated teams.
Microsoft Editor — bundled with Microsoft 365. Free enough for casual users; genuinely weaker on style and tone than Grammarly. Fine if you already pay for Microsoft 365 and do not want another subscription.
ChatGPT or Claude — the "I could just paste it in" alternative. Free tiers can proofread. Losing coverage across every text field on your machine is the trade-off — Grammarly's habit is what makes it work.
For the head-to-head deep dive on when to pick which, read: QuillBot vs Grammarly vs DeepL: Best AI Writing Assistant in 2026. Short version: most content teams end up on two of the three.
Install the free extension at grammarly.com. Chrome, Safari, Edge, or Firefox. Sign up with an email — the free plan is honestly usable and does not require a card.
Add the native app. macOS and Windows both have native apps that catch text fields the browser extension misses — Slack desktop, Notion desktop, Microsoft Teams, and any other app that renders text outside the browser.
Add Grammarly to Word and Google Docs. The Word plugin and Docs add-on unlock the full document experience — Grammarly inside your writing tool of choice.
Use the free tier for a week. Write your normal emails, docs, LinkedIn posts, and Slack messages. Note how often you dismiss suggestions vs. accept them.
Upgrade to Premium if the tool sticks. At grammarly.com/premium — $12/month annual is the pick. Monthly at $30 exists to push you to annual.
If you run a team, evaluate Business. The brand voice profile and team style guide features are the ROI. Book a demo through grammarly.com/business for teams above roughly 20 seats.
Is Grammarly better than ChatGPT for writing? For catching typos, subtle grammar, and register mismatches across every app you type in — yes. For drafting from a blank page, no. The tools do different jobs; most writers end up using both.
Does Grammarly train on my writing? Grammarly states it does not use user content to train external models. Documents are processed by Grammarly's own systems. Business and Enterprise plans include stronger data-handling commitments. For sensitive drafts (legal, medical, financial), read the current privacy and terms and consult your compliance team.
Is Grammarly worth it if I already use Microsoft Editor? Yes, if you write a lot. The grammar engine is deeper, tone detection is stronger, and coverage across non-Office apps (Slack, Gmail, LinkedIn, Twitter, Notion) is meaningful. If you write mostly inside Word, Editor plus free Grammarly is a reasonable stack.
Can I use Grammarly for commercial writing? Yes. All Grammarly plans permit commercial use of the output. Grammarly does not claim rights over your writing.
How is Grammarly different from QuillBot? Grammarly polishes what you wrote; QuillBot rewrites what someone else wrote. Grammarly is stronger on subtle grammar and tone; QuillBot is stronger on paraphrasing and summarizing. Most working writers eventually use both.
Does Grammarly's plagiarism checker replace Turnitin? For personal use — checking a draft against the public web — yes. For institutional use with student submissions and larger databases — no. Turnitin still wins for schools and universities.
Grammarly Premium at $12/month annual is the highest-value subscription in the writing category for anyone who writes on a computer more than an hour a day. The grammar engine is the deepest on the market, tone detection is feedback you cannot easily get elsewhere, and coverage across every text field on your machine turns the tool into an unconscious habit — the mistake gets caught before you post it. There is a reason 30 million daily active users open the tool without thinking. It just works, everywhere.
Where Grammarly stops being the right answer: paraphrasing and summarizing (QuillBot wins), translation (DeepL wins), and blank-page original drafting (ChatGPT and Claude win). Grammarly does not claim to do those jobs, and pretending it can leads to bland outputs and disappointed users. For polish and consistency, though, nothing else is close.
The honest recommendation: install the free extension at grammarly.com, use it for a week on your real writing, and upgrade to Premium annual if you catch yourself accepting more suggestions than you dismiss. For teams above 20 writers, evaluate Business — the brand voice enforcement is a real capability nothing else in the writing space matches. And if you want the honest head-to-head against the other two writing-tool contenders, our full comparison is here: QuillBot vs Grammarly vs DeepL. Most working writers eventually pay for two of the three.