Grammarly
WritingThe AI assistant that catches mistakes before you hit send.
Grammarly checks your writing for grammar, spelling, and tone as you type, then suggests full-sentence rewrites to make it clearer, right in your browser, email, or docs.
Visit GrammarlyWhat can Grammarly do?
Catch grammar and spelling mistakes: Flags errors in real time as you type, across your browser, email, and docs.
Rewrite full sentences in one click: Turns a clunky sentence into a clearer one instantly, no manual editing needed.
Adjust your tone: Flags how your writing reads, formal, friendly, or confident, and lets you shift it before sending.
Detect plagiarism and AI-generated text: Checks your draft against billions of web pages and flags AI-written passages on paid plans.
Works almost everywhere you write: Browser extension, desktop app, and integrations with Gmail, Docs, Slack, and Word.
Quick Facts
Free Plan?
Yes, core checks are free
Pricing
From $12/month
Launched
2009
Headquarters
San Francisco, USA
Pros
Catches mistakes most spellcheckers miss: Goes beyond typos to flag awkward phrasing, passive voice, and tone problems.
Works almost everywhere you type: The browser extension covers Gmail, Slack, Docs, and most websites, not just one app.
Generous free plan: Core grammar and spelling checks are free forever, not just a trial.
Fast, one-click rewrites: Full-sentence suggestions save time over manually rewriting yourself.
Cons
Billing and auto-renewal catch people out: The annual plan renews automatically at full price unless you cancel ahead of time, and that charge often comes as a surprise.
Support is slow when something goes wrong: Getting a billing or account issue resolved can take longer than it should.
AI content generation is an add-on, not the main event: The prompt-based generation is capped and fairly basic. Grammarly is still primarily an editor, not a content generator.
Pricing
Free: $0
Grammar and spelling checks, tone detection, and 100 AI prompts a month.
Pro: $12/month
Most popularUnlimited suggestions, full-sentence rewrites, plagiarism detection, and 2,000 AI prompts a month.
Enterprise: Custom
SSO, unlimited style guides and brand tones, and advanced security controls.
Pricing and features may have changed. Check Grammarly's website for the latest details.
Knowtably Rating
Knowtably's Take
Grammarly earns its reputation: it catches real mistakes, not just typos, almost everywhere you write. It's built to polish writing you've already drafted, with AI generation as a capped add-on rather than the core product.
We'd choose this if: You want your everyday writing, emails, docs, messages, checked for grammar, clarity, and tone without leaving the app you are already using.
We wouldn't choose this if: You need to generate blog posts or ad campaigns as your main task. Grammarly's AI generation is a limited add-on, not built for high-volume content creation.
Excellent
Knowtably Rating
Quick Facts
Free Plan?
Yes, core checks are free
Pricing
From $12/month
Launched
2009
Headquarters
San Francisco, USA