AI for Writing & Content

Grammarly AI — The Complete Guide

Grammarly is the world's most used AI writing assistant — 30 million daily users, works inside every app. Real-time grammar, clarity, tone detection and generative AI rewrites wherever you write. Free tier for grammar basics. Premium: $12/month.

AI Writing Assistant30M+ usersWorks everywhereFree tier availablePremium: $12/monthLast reviewed: April 2026

What is Grammarly?

Grammarly is the world's most widely used AI writing assistant, with over 30 million daily active users and 70,000 teams. It works inside almost every writing environment you already use — Gmail, Outlook, Google Docs, Microsoft Word, LinkedIn, Slack, WordPress, and 1 million other apps and websites via browser extension — checking your writing for grammar, spelling, punctuation, clarity, tone and style in real time.

In 2026, Grammarly goes significantly beyond grammar checking. Its generative AI features allow you to draft emails and messages from scratch, rewrite passages in different tones, summarise long documents, and get suggestions that transform weak writing into polished professional communication. The key is that it works everywhere — you do not need to copy text to a separate tool, then copy it back.

Grammarly's free tier covers basic grammar and spelling across all platforms, which is genuinely useful and more capable than the default spell-checker in most apps. Premium adds full AI writing assistance, sentence-level rewrites, tone adjustment, vocabulary enhancement and plagiarism detection.

What Grammarly does

Real-time grammar and spelling — Detects errors as you type across all connected apps. Goes beyond simple spell-check to catch complex grammatical issues, punctuation errors and awkward phrasing.

Clarity and conciseness suggestions — Identifies sentences that are wordy, overly complex or confusing. Suggests specific improvements. Particularly valuable for business writing where clear, concise communication matters.

Tone detection — Analyses the tone of your writing (confident, friendly, formal, assertive etc.) and suggests adjustments if the tone is off for the context. The tone detector is particularly useful for email — showing you whether your message might read as passive-aggressive, overly casual or unclear before you send it.

AI sentence rewrites — Highlights weak or problematic sentences and offers AI-generated rewrites. You review and accept or reject each suggestion. Faster than rewriting from scratch; better than leaving the weak sentence in.

Generative AI — Draft an entire email or response from a brief description. Rewrite a whole paragraph in a different tone. Summarise a long document. These features work inline in your writing environment.

Plagiarism detection — Checks your text against billions of web pages. Included on Premium. Useful for academic work, content marketing, and verifying that AI-generated text has not reproduced source material too closely.

Grammarly Business style guide — Teams can create a company-wide style guide that Grammarly enforces across all team members' writing — brand-specific terminology, formatting preferences, tone guidelines. Ensures every piece of external communication follows company standards.

Who Grammarly is for

Anyone who writes professionally in English and wants their writing to be clearer, more accurate and better-toned. This is genuinely a broad category: business professionals writing emails, marketing teams producing copy, students writing assignments, customer support agents, HR managers, sales reps, executives. Grammarly works best for professional and business writing — its grammar-first approach can be frustrating for creative writers where intentional rule-breaking is part of the style.

Is Grammarly free?

Yes. The free tier covers basic grammar and spelling across all connected platforms — this alone is better than most built-in spell-checkers and is genuinely useful. Premium is $12 per month billed annually and adds full AI writing assistance, style suggestions, plagiarism detection and tone adjustment. Business is $15 per user per month billed annually and adds team style guides, brand tone enforcement and centralised billing.

Getting started with Grammarly

Step 1 — Install the browser extension

The Grammarly browser extension is the fastest way to start. Install it from the Chrome, Firefox, Safari or Edge store. Once installed, Grammarly works automatically inside Gmail, Google Docs, LinkedIn, WordPress, Notion and any other web-based writing tool. No setup required beyond signing in.

Step 2 — Install desktop apps

Download the Grammarly desktop app for macOS or Windows. This extends coverage to Microsoft Word, Outlook desktop, Slack desktop, and text fields in applications that are not browser-based. Install, sign in — it runs in the background and checks writing automatically.

Step 3 — Configure your writing goals

In any Grammarly-checked document, click the Goals button. Set: audience (general / knowledgeable / expert), formality (informal / neutral / formal), domain (general / academic / business / technical / creative), intent (inform / describe / convince / tell a story). Grammarly tailors its suggestions to these goals, reducing irrelevant suggestions.

Step 4 — Use the tone detector

For any email before sending: check the tone detector on the right side of the Grammarly panel. It shows how your message will likely be perceived — if it reads as passive-aggressive, overly casual, or confusing, adjust before sending. This is one of the most practically useful Grammarly features for professional communication.

14 Grammarly use cases

Professional email

Rewrite a draft email for tone
Take this email draft and rewrite it to sound [more professional / warmer / more direct / less aggressive]. Keep the key message identical. Adjust: word choice, sentence structure, and tone markers. Do not add information that was not in the original. Target reader: [describe their role and relationship to you].
Draft a difficult email
Write a professional email: Situation: [describe the situation — declining a request, delivering bad news, giving critical feedback, pushing back on a decision]. Recipient: [describe their role]. Key points to include: [list]. Tone: direct but respectful. Length: under 150 words. Keep it clear, honest, and action-oriented.
Make an email more concise
Rewrite this email to be 30% shorter. Remove: filler phrases, redundant statements, unnecessary preamble. Keep: every piece of information the recipient needs to act. Make the primary ask or action clear in the first 2 sentences. [Paste email to rewrite]

Business writing

Rewrite for executive audience
Rewrite this [document / email / report section] for an executive audience. Prioritise: key takeaway in the first sentence, supporting evidence second, recommendations last. Remove: jargon, hedging language, unnecessary context. Target reading time: 2 minutes or less.
Improve clarity of technical writing
Rewrite this paragraph to be clearer for a non-technical audience. Replace jargon with plain language. Break complex sentences into shorter ones. Keep all the information, just make it accessible to someone without a [technical / industry] background. [Paste paragraph]
Formal to conversational
Rewrite this [formal / academic / technical] paragraph in a conversational tone. Keep the substance identical. Make it feel like you're explaining it to a smart colleague over coffee, not writing a report. Use contractions, shorter sentences, and more direct language.

Content quality checks

Pre-publication content review
Review this article/post for: factual claims without citation, statements that could be perceived as biased, sentences over 30 words that should be split, passive voice that should be active, overused words or phrases, and weak transitions between sections. Provide specific suggestions for each issue found.
Tone consistency check
Review this [article / email sequence / website copy] for tone consistency. Identify: any sections that shift from the established [professional / conversational / authoritative] tone, any words or phrases that feel off-brand, and any sentences that are significantly more formal or informal than the rest. Suggest corrections.
Summarise a long document
Summarise this [report / article / meeting notes / email thread] into: a 3-sentence executive summary (what happened, what matters, what to do next), 5 key takeaways as bullet points, and any action items with responsible parties. [Paste document]

Tips for Grammarly

Set Goals for each document type. A casual email and a formal business proposal should have different Grammarly settings. Take 30 seconds to set Goals when you open a new important document — you will get more relevant suggestions and fewer false positives that flag intentional stylistic choices.

Do not accept every suggestion. Grammarly's suggestions are recommendations, not rules. For professional business writing, accepting most suggestions improves clarity. For content with a distinctive voice or intentional stylistic choices, review each suggestion critically. Accept what improves communication; ignore what would flatten your voice.

Use the tone detector before sending difficult emails. The most practically valuable Grammarly feature for most professionals is the tone detector applied to emails about sensitive topics — performance issues, declined requests, complaints, disagreements. Reading the tone analysis before sending reduces misunderstandings that could have been avoided.

Technical background

Grammarly was founded in 2009 and is headquartered in San Francisco. Per Grammarly's official website, the platform serves over 30 million daily active users and 70,000 teams. It works across 1 million+ apps and websites via browser extension, with native integrations in Microsoft Office and Google Workspace.

How Grammarly checks writing

Grammarly uses a combination of rule-based grammar systems and neural language models to evaluate writing. The grammar and punctuation checks are rule-based — deterministic corrections against known grammatical patterns. Clarity suggestions, tone analysis and generative rewrites use neural language models that have been trained on professional writing corpora and fine-tuned with human feedback from Grammarly's editorial team.

Privacy and data

Per Grammarly's official privacy policy, Grammarly processes the text you write to provide suggestions. On the free and Premium plans, Grammarly may use anonymised data to improve its models unless users opt out in settings. Grammarly Business plans offer stronger enterprise data controls. For sensitive legal, financial or personal writing, review the current privacy settings.

Pricing (verified April 2026)

  • Free: Basic grammar and spelling, all platforms, unlimited text
  • Premium: $12/month (annual) — full AI suggestions, plagiarism detection, tone adjustment, sentence rewrites
  • Business: $15/user/month (annual, minimum 3 users) — team style guide, brand tone, centralised billing, admin controls
  • Enterprise: Custom — SSO, advanced security, custom contracts
Primary sources cited in this guide