Meet Maggie, PCMag'sNo one's writing is perfect, so it's wise to use an error-checking tool at some point in your process. Grammarly does a great job of correcting your writing, working in the background as you type to identify grammar, punctuation, and spelling issues. Using a custom-built AI engine, the productivity app can even generate content such as blog posts, messages, and progress reports, as well as detect AI-generated and plagiarized prose. Of course, you shouldn't rely on Grammarly too much; its style suggestions can take the character out of your writing, and its AI-generated text sometimes sounds robotic. We nonetheless recommend Grammarly to both beginner and veteran writers because of its seamless ability to improve your grammar and tone.
Grammarly's owner is now called Superhuman. In addition to Grammarly, Superhuman offers three products that use its proprietary AI tech: Coda, Superhuman Go, and Superhuman Mail. Coda is an AI-powered workspace that provides integrated apps for corporate-level projects. Superhuman Go is an AI assistant that gives you suggestions about organizing meetings and answering questions across a wide range of web apps. Superhuman Mail works in Gmail or Outlook to organize your inbox, remind you of important messages, and draft replies or automatically write and send them. You can still subscribe to Grammarly separately, but Superhuman's subscription plans, which include all of the above apps, are available for the same price.
Grammarly offers three plans: Free, Premium, and Enterprise. The Free tier provides basic grammar and spelling corrections, as well as 100 AI generations per month. At this level, Grammarly will identify your writing tone, without providing suggestions on how to improve or tweak it. Although it's not technically part of the plan, Grammarly offers a free citation generator. Simply type in the publication details of a book or essay, and the app returns a correctly formatted citation.
The Premium plan ($12 per person per month, billed annually) unlocks the full suite of tone and style features (including rewriting suggestions), one style guide for your group, priority support, and snippets (easily reusable text strings). You also get 2,000 AI generations per month, in-text citation standardization tools, and the ability to detect AI-generated and plagiarized text. For this review, I tested a Premium subscription. A seven-day trial is available for this plan.
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Finally, the Enterprise level offers more in terms of AI capabilities, analytics, collaboration, support, and security.
Grammarly offers desktop (macOS and Windows) and mobile (Android and iOS) apps, extensions for every major browser, and a full-featured web app. The app operates differently on different platforms. For example, on mobile, Grammarly functions as a keyboard. On both macOS and Windows, it runs automatically in Microsoft 365 apps and works seamlessly with the systems' default apps.
On Windows, Grammarly supports an ever-growing number of third-party apps, including Discord, Facebook Messenger, Slack, Thunderbird, and WhatsApp. That said, it didn't work with every word processor I tried. On macOS, Grammarly appears to work with every app that uses the system's native text-editing features, but not with third-party apps like LibreOffice that have custom editing functions. For apps that Grammarly doesn't natively support, you can simply paste text into the service's browser-based editor to get corrections and suggestions.
Grammarly feels more reliable on macOS. You can access its features at any time from an unobtrusive tab on the left edge of the screen, and even open a window to chat with its AI. On Windows, you need to click on a floating status icon that appears in the lower right corner of a supported app window by default. Moreover, after working for several hours on my Windows PC, Grammarly sometimes suddenly reported that it was “temporarily unavailable” because it couldn’t connect to my security settings. The Microsoft Store version of the app appears to be more stable, but I still experienced intermittent issues.
Like on Windows, Grammarly appears on web text boxes as a floating status icon that shows the number of issues it detects. When you click on the icon, Grammarly opens a small window (or a sidebar) that guides you through each issue in turn, allowing you to accept or dismiss its suggestions. It uses colored underlines to flag problems in your writing: red for grammar, punctuation, and spelling; blue for clarity and conciseness; green for suggestions that make your writing more lively; and purple for adjusting the level of formality and friendliness. You can pause suggestions for a session—or forever—via the power button that appears when you hover over the floating status icon. It's also possible to turn off the underlines for corrections you don't want to see via Grammarly's settings.
The app does a good job of explaining its fixes in straightforward language. For example, it might tell you that it flagged a word as erroneous because you used a British spelling when the rest of your prose uses American spellings. It gives simple examples of correct grammar usage as well.
Grammarly’s browser-based editor lets you upload DOCX, ODT, RTF, or TXT files or start from scratch. When you open a document, a right-hand panel offers writing suggestions and (with the Premium version) the ability to check for AI-generated or plagiarized text. You can set writing goals related to audience, domain, formality, and intent, and Grammarly assigns an overall writing score based on language, readability, and word count. Finally, its AI-based Reader Reaction agent provides questions that readers or a lecture audience might ask. In my random sampling of documents, the suggested reactions seemed plausible enough to warrant consideration. Occasionally, I experienced an issue where the web interface indicated that AI features were temporarily unavailable.
I tested Grammarly's plagiarism detection tool by pasting paragraphs from my own publications to see if it could identify the original essays. Grammarly sometimes found the source in a few seconds, but it failed to identify it in one instance. Seemingly, the difference is that it didn't catch sources that were either behind a paywall or from a printed book. What that means is that you can likely trust positive results here, but that negative results don't necessarily mean that the text is original. Keep in mind that if the prose you’re checking includes quotations from published work, Grammarly will flag those as plagiarized.
If you pay for Grammarly's Premium plan, you can click on a menu button to get AI-based suggestions, including rewrites of whole sentences. When I asked it to write an introductory email with personal details, it produced something that sounded eerily like a scam message. The text began, “I hope this message finds you well,” and maintained a tone that was overly polite throughout. When I asked it to write an essay on the work of a well-known scholar, it hallucinated the title and contents of books that the scholar never wrote.
When I asked the same question to other AI chatbots, Google’s Gemini produced the most accurate answer; Microsoft Copilot was vague about the facts, but not hallucinatory; and ChatGPT included a lot of empty verbiage. Only Grammarly went whole-hog with hallucinations.
If you want to sound like someone who uses AI to write ordinary email messages, Grammarly will get the job done. Otherwise, you’re probably better off writing your own less well-polished (but more authentically human) prose.
The app (unfortunately) makes it easy for students to generate essays with AI. When I asked Grammarly to write essays about some famous books, it proceeded to create high-school-style book reports with few specifics. Their lack of structure, poor flow, and bubblingly enthusiastic tone easily give them away, however. The good news is that Grammarly will detect AI content you create with it.
If you’re already a skilled writer, Grammarly can catch trivial errors you might be too impatient to see. Some of its simple suggestions to change punctuation or word order can also be convenient. That said, you might find its real-time grammar and spelling checks distracting in Microsoft Word, Google Docs, and other apps for long-form writing, even if the same feature is helpful for emails and web forms.
If you write anything above high-school-level prose, Grammarly is likely to get in your way. It might suggest you write something entirely different from what you intend, prompt you to emphasize something you don't want to, or both. Of course, as mentioned, Grammarly lets you fine-tune its suggestions. If you want to start sentences with “And” or “But,” despite the stuffy rule books that tell you not to, you can prevent Grammarly from flagging those sentences for revision. Its ability to detect typos could still be useful, however.
If you’re doubtful about your writing skills, Grammarly can help in dozens of ways. It's reliable for checking punctuation and spelling, and it works significantly better than it did when I last tested it a few years ago. Back then, it made dozens of suggestions that would have changed my meaning without improving my style, but it has mostly stopped doing that. And now, it has an AI-powered Expert Review agent that provides suggestions based on subject matter experts, some of whom are living and some who are deceased. (A small-type warning explains that the experts aren't affiliated with Grammarly). Despite these improvements, Grammarly can still make you sound stuffy when you want to sound relaxed or deliberately vague. One minor example is that it didn’t want me to refer to some miscellaneous things as “stuff,” but, again, you can always ignore or overrule its suggestions.
I earn my living partly from writing and from helping other people learn to write, so when I started testing Grammarly, I didn’t expect it to do my job for me. After spending many days with Grammarly looking over my shoulder while I used a half-dozen apps on Windows and macOS, I have mixed reactions. I’m grateful to it for catching my typing errors, alerting me to words that I typed in the wrong order, and reminding me to add commas where necessary. I also like some of its suggestions to cut down the length of sentences.
You should know better than to accept Grammarly’s less competent suggestions, but you still might find it tempting to quickly accept its help to rewrite your prose. Be careful; it could change your words to say something you don't mean.
I don't expect Grammarly to improve the prose of great communicators like Winston Churchill, but you can get an idea of how the app thinks by asking it to review one of Churchill’s great speeches. When I uploaded one of those speeches, Grammarly gave it a writing quality score of 84 out of 100, and nudged his vivid prose toward something more generic, more bland, and more machine-like. It might make your writing slightly less awkward, but it won’t help you to write anything vibrant and convincing.
Final Thoughts
(Credit: Grammarly)
Grammarly
- 5.0 - Exemplary: Near perfection, ground-breaking
- 4.5 - Outstanding: Best in class, acts as a benchmark for measuring competitors
- 4.0 - Excellent: A performance, feature, or value leader in its class, with few shortfalls
- 3.5 - Good: Does what the product should do, and does so better than many competitors
- 3.0 - Average: Does what the product should do, and sits in the middle of the pack
- 2.5 - Fair: We have some reservations, buy with caution
- 2.0 - Subpar: We do not recommend, buy with extreme caution
- 1.5 - Poor: Do not buy this product
- 1.0 - Dismal: Don't even think about buying this product
Read Our Editorial Mission Statement and Testing Methodologies.
Grammarly is as good as any app we’ve tested at correcting straightforward grammar and spelling errors, and it provides useful explanations of its fixes. It's also available almost anywhere you might want to use it and features decent tools for detecting AI-generated and plagiarized work. If you want another pair of eyes to check on your writing as you go, Grammarly can be invaluable. Just keep in mind that it may not always accurately understand your intent or perfectly match your style with its AI-powered suggestions. At the very least, we recommend most writers try out its free version to take advantage of its basic corrections.
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About Our Expert
I've been writing about software and hardware for PCMag for more than 40 years, focusing on operating systems, office suites, and communication and utility apps. I've specialized in everything related to word and document processing, including format conversion, OCR, and PDF apps. In my spare time, I build apps for Macs and Windows PCs that make it easy to run legacy operating systems (such as old versions of macOS and Windows) and work with legacy documents.
I've also written about technology for non-technical publications, such as The New York Review of Books. Before joining PCMag, I reviewed music and sound equipment for audio magazines. In my other career, I'm the Lionel Trilling Professor in the Humanities at Columbia University and write books about modern literature.
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