A practical comparison of Grammarly Free and Grammarly Pro for grammar checking, tone, clarity, rewrites, plagiarism detection, AI detection, AI prompts, academic writing, professional emails, and value for money.
A practical comparison of Grammarly Free and Grammarly Pro for grammar checking, tone, clarity, rewrites, plagiarism detection, AI detection, AI prompts, academic writing, professional emails, and value for money.
Best all-round free writing assistant with a strong paid upgrade
Anyone who wants free spelling, grammar and tone checking with an optional upgrade for deeper rewrites
4.5/5 Tool Verdict ratingBest for continuous writing support across many applications
Individuals and teams that write frequently across browsers, office software, email and business applications
4.3/5 Tool Verdict ratingBest for
Grammarly
Anyone who wants free spelling, grammar and tone checking with an optional upgrade for deeper rewrites
Grammarly Pro
Individuals and teams that write frequently across browsers, office software, email and business applications
Verdict
Grammarly
Best all-round free writing assistant with a strong paid upgrade
Grammarly Pro
Best for continuous writing support across many applications
Tool Verdict rating
Grammarly
4.5/5
Grammarly Pro
4.3/5
Pricing tiers
Grammarly
Spelling, grammar, basic tone detection, up to 100 AI prompts/month.
Full-sentence and tone rewrites, plagiarism/AI detection, up to 2,000 AI prompts/month.
SSO, security review and centralised admin.
Grammarly Pro
Grammar, spelling, tone visibility and 100 AI prompts per month at verification.
Advanced rewrites, tone adjustment, brand support and 2,000 AI prompts.
Same core Pro capability with monthly flexibility.
Advanced controls, provisioning, security and organisation features.
Free plan
Grammarly
Yes — Free covers spelling, grammar, basic tone detection and up to 100 AI prompts/month, no card required.
Grammarly Pro
Yes — Grammarly Free covers core correctness and limited AI assistance. Pro is the paid plan for advanced rewriting, tone, fluency, plagiarism and AI detection, brand controls and higher prompt limits.
Platforms
Grammarly
Web, Windows, macOS, iOS, Android, Chrome, Safari, Firefox, Edge, Microsoft Word, Google Docs
Grammarly Pro
Web, Windows, macOS, iOS, Android and extensions or integrations across supported applications
Main strengths
Grammarly
Best for Editing; Writers and professionals
Grammarly Pro
Works across a broad range of writing surfaces
Strong sentence-level rewriting and tone support
Individual and team features in the Pro plan
Clear free tier for testing the workflow
Watch-outs
Grammarly
Check current plan limits, usage caps, export rules, privacy settings, and whether the tool fits your exact workflow before committing.
Grammarly Pro
Monthly pricing is expensive compared with annual billing
Suggestions can flatten voice or introduce unintended meaning
Sensitive or regulated text needs policy review
AI detection should not be treated as definitive evidence
Integrations
Grammarly
Browser, web, desktop, mobile
Grammarly Pro
Browsers, Google Docs, Microsoft Word, Outlook, Gmail, Slack, Salesforce, Microsoft Teams and many supported desktop and web applications.
Summary
Grammarly
Grammarly is a free-to-start writing assistant covering spelling, grammar and basic tone, with a Pro tier from $12/month (billed annually) adding full-sentence rewrites, plagiarism/AI detection and a much larger AI prompt allowance.
Grammarly Pro
Grammarly Pro is valuable when writing quality is a repeated operational need rather than an occasional edit. Its main advantage is availability across many applications; buyers should still review factual claims, sensitive text and whether the annual saving justifies commitment.
Best overall choice
Grammarly
Better for casual users who mainly need spelling, grammar, basic tone feedback, and light writing support.
Grammarly Pro
Better for students, professionals, freelancers, marketers, and regular writers who need deeper suggestions, rewrites, plagiarism checks, AI detection, and stronger writing feedback.
Best for students
Grammarly
Good for basic essay checks, spelling, grammar, tone awareness, and avoiding obvious mistakes.
Grammarly Pro
Better for students who write regularly and need clarity improvements, rewrites, plagiarism checks, AI detection, fluency support, and more detailed writing help.
Best for professionals
Grammarly
Good for everyday emails, simple documents, quick typo checks, and basic writing confidence.
Grammarly Pro
Better for important emails, reports, applications, client communication, proposals, and writing where polish matters.
Best for casual writing
Grammarly
Usually enough for social posts, short emails, simple messages, and occasional documents.
Grammarly Pro
Often unnecessary unless casual writing still needs professional tone, rewrites, or advanced feedback.
Best for long-form writing
Grammarly
Useful for catching basic errors, but limited for deeper editing.
Grammarly Pro
Better for improving clarity, tone, fluency, structure, and originality across longer documents.
Should you pay for Grammarly Premium?
Choose Grammarly Free if you only need basic spelling, grammar, and tone checks. It is a strong free writing assistant for casual emails, simple documents, short messages, and occasional writing.
Choose Grammarly Pro if writing quality matters regularly. The paid plan is more useful for students, professionals, freelancers, marketers, non-native English speakers, and business users who need deeper clarity suggestions, tone adjustments, rewrites, plagiarism detection, AI detection, and more AI writing support.
For casual users, Grammarly Free is usually enough. For regular writers, Grammarly Pro is the better option and is easier to justify when it saves time, catches mistakes, and makes important writing sound clearer and more professional.