Grammarly

What is Grammarly?

Grammarly is a writing assistant that checks grammar, spelling, punctuation, tone, and clarity as a person types, and it works inside browsers, word processors, email clients, and its own desktop and web apps rather than in one single place. The tool sits underneath whatever a person is writing and flags problems inline, then offers a one click fix or a short explanation of why the change helps.

How it works
Grammarly runs two kinds of checks. The first kind is rule based and catches spelling mistakes, subject verb agreement, punctuation errors, and repeated words. The second kind is a large language model layer that looks at tone, clarity, conciseness, and whether a sentence actually says what the writer meant. This second layer is what separates Grammarly from a basic spellchecker, since it can suggest a full rewrite of an awkward sentence rather than just underlining a single word.

The workflow
The workflow is mostly passive. A person installs the browser extension or the desktop app, and Grammarly then reads whatever they type in supported fields, whether that is a Gmail draft, a Google Doc, a Slack message, or a Word file. Suggestions appear as colored underlines, and clicking one shows the fix along with a short reason. For longer pieces, the built in editor gives a full report covering correctness, clarity, engagement, and delivery, each scored separately so a writer can see exactly where a document is weak.

AI writing and rewriting
Grammarly also includes a generative writing feature that can draft an email, rewrite a paragraph in a different tone, summarize a long document, or expand a short outline into full sentences. This sits alongside the correction features rather than replacing them, so a person can either fix their own writing or ask the tool to produce new text from a prompt.

Tone detection
Tone detection is one of the more distinctive parts of the product. Grammarly reads a piece of writing and labels the tone it is giving off, for example formal, friendly, or blunt, and flags cases where the tone does not match the apparent goal of the message, such as a customer support reply that reads as curt. This is useful for people writing in a second language or anyone who wants to double check how a message will land before sending it.

Built for teams
For teams, Grammarly Business adds a shared style guide, so a company can define preferred terminology, banned words, and formatting rules, and every team member's suggestions adjust to match that guide automatically. It also includes an analytics dashboard showing how consistently the team's writing follows the guide over time.

Pricing tiers
The free tier covers the core grammar and spelling checks plus a limited set of tone and clarity suggestions. The paid Premium tier unlocks full sentence rewrites, plagiarism detection, and more detailed tone coaching, while Business adds the style guide and admin controls. Grammarly does not require an internet connection for basic spellcheck in most integrations, but the advanced AI suggestions need a live connection since they run on Grammarly's servers rather than locally.