Article updated on April 2, 2024 at 7:30 AM PDT

Grammarly Review: An AI Editing Gem With Flaws

Grammarly isn't your mother's spell checker. The AI-powered editing tool has a lot to offer.

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Katelyn Chedraoui
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Katelyn Chedraoui Associate Writer
Katelyn is an associate writer with CNET covering apps, software and online services. She graduated from the University of North Carolina at Chapel Hill with a degree in media and journalism. You can often find her with a paperback and an iced coffee during her time off.
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7.0/ 10


Buy at Grammarly


  • Holistic editing and grammar suggestions
  • Works with many services, including Microsoft and Google accounts
  • Paid features include plagiarism detection and generative AI tool
  • Can turn on and off certain grammar rules


  • Sometimes annoying or unnecessary suggestions
  • Detailed assessments are available only in web browser
  • Many helpful features are included only in paid plans

When you think about AI, Grammarly probably isn't the first service to pop to mind. You likely think of newer chatbots such as ChatGPT and Google's Gemini, or maybe Firefly, Adobe's newly upgraded AI image generator. But AI certainly isn't limited to only these spaces -- Grammarly's been using it for years to help you improve your writing.

I've been using Grammarly for several months now. I admit that in the beginning, I didn't think I needed an extra digital editing tool. Human editors, absolutely yes, but I was sure my built-in tools would cover my basic needs. But after my in-depth testing of Grammarly's services, it's clear I was wrong. Grammarly's catching errors in this review as I'm writing it. (Not to worry -- they'll be resolved by the time you're reading this.)

Grammarly rightfully touts itself as more than a simple spell checker. In its Basic plan, Grammarly monitors and analyzes your writing against a laundry list of grammar rules, giving you more comprehensive suggestions compared with built-in tools. The paid plans offer a variety of features that help you adjust the tone of your writing, scan for plagiarism and customize to your writing preferences. And not to be outdone by those aforementioned AI chatbots, Grammarly has a generative AI tool that helps you build outlines, brainstorm ideas and even generate text. 

My experience using Grammarly has been positive overall, but the service isn't perfect. As with any editing tool, it's up to you to decide what's right for your writing and decline wonky suggestions. Grammarly's free plan offers good, comprehensive help that's suitable for folks who want strong editing without breaking the bank. But if you're looking for more editing firepower, or you're writing in professional settings with stricter style and tone requirements, consider investing in a paid plan.

How CNET tests AI tools

CNET takes a practical approach to reviewing AI tools, with the goal of determining how good AI is at performing the task it promises to assist. These tests vary by tool, for example, evaluating the quality of summaries from Otter AI, a meeting assistant, and whether AI suggestions from Grammarly, the writing assistant we're reviewing here, help the process. We score the tool on a 10-point scale, which considers the overall usefulness of the tool and whether AI improves its effectiveness. See how we test AI for more.

What you'll get with Grammarly's basic editing service

Grammarly's free plan provides access to its basic editing service, which helps detect and correct errors in three main areas: spelling, grammar and punctuation. You'll also get suggestions for improving the clarity of your writing. Grammarly's recommendations will make your writing more concise, which I found super helpful as my sentences tend to run long. The last feature in the free plan is tone detection. However, suggestions about how to change your tone are limited to paid plans.

Grammarly offers two paid tiers: Premium (starting at $12 per month) and Business (starting at $15 per month). They offer almost identical editing features, but the Business plan allows for more streamlined team tools, including centralized billing and the ability to upload and manage style guides.

Grammarly is available on your laptop and smartphone through downloadable apps and browser extensions, allowing it to work with many different services. When you download the Grammarly desktop app in addition to the web browser extensions, it will automatically activate when you're writing in other places, like in your email, documents and messaging systems. The smooth integration across all my workspaces was a major plus. For folks who don't want to download yet another app, Grammarly works just fine in a web browser.

Overall, Grammarly caught many errors and improved my writing. However, there were instances where the edits it suggested were incorrect or would've changed my intended meaning. I would caution Grammarly users not to blindly accept all suggested edits -- take a minute to make sure they look right before accepting the changes.

Easy to customize to your writing preferences

Grammarly makes it easy to customize your suggestions and tone to what you want. It lists over 45 of the most common grammar rules that you can toggle on and off depending on your style guide, personal style or preferences. To see this, go into Account > Customize > Writing Preferences.

Grammarly's writing preferences were particularly helpful for me as a writer at CNET, where we don't use serial commas. The serial, or Oxford, comma was a common suggestion from Grammarly, and the notifications were annoying until I figured out how to turn them off. With the Business plan, your organization can upload its style guide and integrate its rules into the edits Grammarly suggestions, which is a great time-saver. I also appreciated Grammarly's rules around using inclusive language, which flag phrases or words that might be outdated, inaccurate or disrespectful -- particularly regarding gender and sexual orientation, ability, age and human rights.

The feature that most excited me was tone suggestions. With paid plans, Grammarly can recommend changes to your writing that give it a different tone. The edits I got most often adjusted my writing to sound more active and confident. I know from experience that my rough drafts tend to be too passive, so I appreciated how this tool helped me catch some of those spots early on in my writing process. 

One feature I would've liked is the ability to highlight a sentence and request that Grammarly give me suggestions about how to change the tone -- currently, you can get recommendations only for sentences Grammarly marks or by putting it in GrammarlyGo.

A good, not great, plagiarism scanner

One of Grammarly Premium's standout features is a plagiarism scanner. After playing around with it, I've found it's a nice perk, but it's not flawless.

Grammarly says that it checks your work "against billions of web pages." After it scans your text, it gives you a percentage of how similar your sections are to published work, along with a link to where existing text appears online. I tested it by creating a series of documents, some original and some containing intentionally plagiarized work, to see how much Grammarly would catch.

At first glance, it's a good general tool, if not always the most accurate. Below, Grammarly correctly flagged the plagiarized second and third paragraphs. The first paragraph has correct credit and citation, but Grammarly still added a flag to point out that some of the text -- the direct quote -- was similar.

screenshot of how Grammarly scans for plagiarism

In this example, I added proper citation at the beginning of the first paragraph. Grammarly correctly notes the second and third paragraphs are plagiarized from another CNET article (intentionally done for this test).

Grammarly/Screenshot by CNET

Sometimes, Grammarly didn't catch places where I added intentionally plagiarized sections. Grammarly's support page says there can be a lag for recently published work. 

To ensure that you're getting the most thorough scan, I recommend closing and reopening the document to get the software to reload or copying and pasting the final version of your work into a new document. Even then, if you're worried your work might be considered plagiarism, a good rule of thumb is to add a citation and clarify where the idea is from.

GrammarlyGo: Great for outlines and tone adjustments

GrammarlyGo is a generative AI-powered feature that generates text based on your suggestions and prompts. Grammarly introduced the feature in May 2023, following ChatGPT's explosion in popularity. GrammarlyGo is currently available only to premium users with a limit of 1,000 prompts per month. Business and enterprise users get unlimited prompts if your company doesn't disable the feature.

One of the best things you can do with GrammarlyGo is generate outlines or brainstorm ideas. When I tested the feature, it produced thorough outlines and many great headlines and section headings. Grammarly helped me create several generic outlines for several kinds of writing, including reviews, blog posts, breaking news stories and academic journal papers. I was pleasantly surprised by how thorough the outlines were, even when you asked for a specific prompt, like "Generate an outline for a blog post about a Costa Rica vacation." Using GrammarlyGo as a brainstorming tool is a great way to spark inspiration and create robust plans. 

screenshot of GrammarlyGo generating a story outline

GrammarlyGo is good for creating outlines and brainstorming ideas.

Grammarly/Screenshot by CNET

GrammarlyGo also allows you to generate whole passages of text by analyzing and rewriting your own work. To test these features, I took a wordy section from one of my other CNET stories to see what Grammarly would change. 

The first prompt I entered had GrammarlyGo identify any gaps in my writing, with little success. The one gap it identified was one I felt as though I had already addressed. I saw minor differences using the "Improve it" prompt. GrammarlyGo kept the section approximately the same length, and each sentence had only a word or two or changed or was given a new structure. When I asked to "Simplify it," Grammarly didn't change most of my sentences, just cut some out. All of these edits were good, but they weren't wielding the kind of editing firepower I was hoping for.

There are many different tones you can ask Grammarly to implement in your piece. "Make it academic" was particularly fun because it took my casual, second-person text and turned it into an overly complicated, third-person, 10-dollar-wordy, journal-style abstract -- in other words, it worked well.

screenshot of two GrammarlyGo prompts

Here, you can compare my original text with what GrammarlyGo came up with based on the prompt "Make it academic." Notice that even in Grammarly's own text there are suggestions waiting for my review.

Grammarly/Screenshot by CNET

The biggest pain was trying to keep track of all of the changes and different versions I was creating. It was difficult to tell what text Grammarly was using as its base to update -- after about four prompts, a row would pop up telling me what it was based on, but the few words in the preview still didn't help me understand what it was using. I would love for Grammarly to highlight or let me select which text passages it used as the basis for prompts. For now, I managed by labeling each section with the prompt before inserting it into the document.

Students, beware GrammarlyGo

Many Grammarly users are students, and I urge caution for students using GrammarlyGo, particularly for text generation. 

After ChatGPT took off, university professors, students and academic integrity offices struggled to define the line between acceptable AI use and what was considered plagiarism. Recently, this debacle led to one student at the University of North Georgia being accused of plagiarism for using Grammarly -- not for generating text, but for using Grammarly for spell check, tone improvements and other editing suggestions. Such suggestions aren't powered by generative AI, Grammarly said in a statement to Her Campus, after the student's TikTok videos about her case went viral. 

In response to the incident, Grammarly jumped on TikTok with a 4-minute-long video featuring its head of education, Jenny Maxwell, explaining how Grammarly's editing services and gen AI work. One feature Maxwell calls out is Grammarly's "one-click way" to cite how generative AI was used in content creation. When I tested it, it spat out a bulleted list, including the prompts I entered and the sections it changed. If you're writing a formal paper, this is likely insufficient to properly acknowledge your use of AI for generating text, as it isn't a formal citation, brief or paragraph to include in a paper.

screenshot of GrammarlyGo acknowledging AI use

This is what GrammarlyGo spits out when you use the prompt "Acknowledge Grammarly gen AI use." 

Grammarly/Screenshot by CNET

Don't get me wrong, this is a great idea, and I hope more AI companies implement citation-like features. But right now, Grammarly's citation tool falls short of what students need. Given the level of scrutiny placed on academic papers, I wouldn't recommend GrammarlyGo for students, especially if your school doesn't have a clearly outlined AI policy or if it regularly uses AI detection tools that may falsely flag your paper as AI-generated. 

TL;DR: Grammarly is impressive, but take it with a grain of salt

Language and its rules are constantly changing, which presents Grammarly and similar services with the monumental task of trying to keep up. Grammarly is a great tool for improving your writing, especially if you struggle with clarity and concision.

The free plan is more comprehensive than most of the built-in tools you might be using now, and it's a great first line of defense when writing. If you're looking for more hands-on suggestions, especially when writing in a specific style or tone, you're going to find the most value in Grammarly's advanced but paywalled features. The plagiarism scanner and gen AI text generator are nice additions, but they aren't flawless.

When you're using online or AI-powered editing services, it's important to remember that while these tools are helpful, they're not meant to be a replacement for human editors. The suggestions they provide are just that -- suggestions. It's up to you to parse through them to decide which of them are going to strengthen your writing and which might be irrelevant or just plain wrong. Grammarly is great for polishing up drafts, clarifying and condensing text, but it won't catch bigger problems with your writing like a human editor would.

Editor's note: CNET is using an AI engine to help create a handful of stories. Reviews of AI products like this, just like CNET's other hands-on reviews, are written by our human team of in-house experts. For more, see CNET's AI policy and how we test AI.