AI writing assistant checking grammar, style, tone, and plagiarism across every platform
Grammarly is the world's most widely used AI writing assistant, with over 30 million daily active users. It checks grammar, spelling, punctuation, clarity, conciseness, and tone across browser extensions, Microsoft Office, Google Docs, desktop apps, and a web editor — providing real-time suggestions wherever writing happens. Grammarly's generative AI features additionally draft, rewrite, and transform text on demand.
Grammarly is a strong fit if its core strengths match your workflow, budget, and support needs. Use the quick signals below before opening the full review.
Grammarly's dominance in the grammar checker category comes from a single product decision made early: go wherever the user writes rather than making the user come to the tool. Its browser extension installs once and then appears in Gmail, Slack, LinkedIn, CMS editors, form fields, and any web-based text input — providing real-time underlines and suggestions without opening a separate application.
Grammarly's suggestion engine identifies grammatical errors (subject-verb agreement, comma splices, article misuse), spelling mistakes, punctuation errors, and stylistic issues simultaneously. The colour-coding system distinguishes error types: red for correctness issues, blue for clarity suggestions, green for engagement and delivery improvements. Writers can accept, dismiss, or review each suggestion inline without breaking the writing flow.
Grammarly Premium's tone detection reads the entire document and identifies the overall emotional register — whether the writing comes across as confident, formal, direct, friendly, cautious, or apologetic. For professional writing where tone mismatch causes communication failures — an email that reads as passive-aggressive when it was intended as neutral, for example — this macro-level feedback catches what word-by-word grammar checking misses.
Grammarly's generative AI layer (Grammarly Go) drafts emails from bullet points, rewrites paragraphs for different tones, summarises long text, and responds to custom prompts — all accessible from the same interface as the grammar checker. For users who want AI writing assistance alongside correction, the combined tool eliminates the need for a separate ChatGPT tab.
Grammarly's free tier covers basic grammar and spelling correction — genuinely useful and sufficient for many casual writing needs. Premium adds clarity suggestions, tone detection, word choice improvements, plagiarism detection, and generative AI. At $12/month billed annually, Premium is best justified for professionals whose written output significantly impacts their work quality and reputation.
Score: 9.2/10 — Best all-round writing assistant with the widest platform coverage; some suggestions favour US English conventions.
Free
Free billed annually
$30/mo
$144/mo billed annually
$15/mo
$180/mo billed annually
Grammarly is best for Professionals and knowledge workers who write in many different tools daily and want real-time correction without context switching, Non-native English speakers who want immediate, in-context grammar and vocabulary guidance, Content teams and agencies who need plagiarism checking alongside grammar correction in one subscription.
Yes. Grammarly currently lists a free plan in ToolRankr data.
It has a free plan.
Grammarly is reviewed using ToolRankr's scoring model for ease of use, value, features, support, and overall quality. Affiliate links may earn a commission, but sponsored labels do not change editorial scoring.
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