9 Best Grammar Checker Software & Tools (Updated 2026)

Are you a writer, student, or working professional who wants to ensure your writing is clear and error-free? Using a grammar checker is an excellent way to polish your work and avoid embarrassing typos and mistakes. But with so many grammar checking tools available, it can be hard to know which one to choose.

In this in-depth guide, we‘ll compare the features and accuracy of the best grammar checkers on the market. Whether you‘re working on a book, essay, blog post or important email, you‘ll learn how to select the ideal grammar checker to make your writing shine.

What to Look for in a Grammar Checker

The best grammar checkers go way beyond the basic spell checkers of the past. Here are the key features to consider:

Spelling and Grammar Checking – At a minimum, a good grammar checker should accurately flag spelling errors, even when the misspelling is still a valid word (e.g. using "there" instead of "their"). It should also catch common grammatical mistakes like subject-verb agreement, misused words, and punctuation problems.

Writing Style and Readability – More advanced checkers provide feedback on your writing style, not just technical mistakes. They suggest ways to make your writing clearer and more engaging, like using active voice, varying sentence length, and avoiding clichés and overused words. Some generate detailed reports on readability measures.

Plagiarism Detection – Plagiarism, whether intentional or accidental, can have serious consequences. Some grammar checkers will scan your text and check it against databases of web pages and published works to verify it‘s original and flag any duplication.

Platforms and Integrations – The best grammar checkers work where you do, with support for desktop and mobile devices and integration with popular apps. Compatibility with online platforms like Google Docs is a big plus.

Ease of Use – A grammar checker should make it simple and intuitive to review suggestions and make corrections. Good tools provide clear explanations of errors and quick fixes with a click.

With these criteria in mind, let‘s see how the top grammar checkers stack up.

Best Overall: Grammarly

Grammarly is our top pick for the best all-around grammar checker. It‘s the most polished and full-featured tool we tested, with outstanding accuracy in detecting errors. Helpful explanations and easy corrections make it a pleasure to use.

Grammarly‘s spelling and grammar checking is the best in the business. In our tests, it successfully flagged errors that other tools missed, like correctly distinguishing between similar words (e.g. affect vs effect) based on context. We felt confident that Grammarly would catch virtually all mistakes.

But Grammarly goes further, helping to improve the overall style and readability of your writing. It calls out wordy phrases, suggests livelier vocabulary, and helps trim unnecessary adverbs and qualifiers. You can even set goals for your writing, like audience and formality level, and get feedback tuned to those parameters.

Another standout feature is plagiarism detection. Grammarly can check your text against a huge database of web pages and ProQuest‘s academic databases. Unlike some other tools, plagiarism checking is included for unlimited use with a paid Grammarly subscription.

Grammarly offers the widest device and platform support of the tools we looked at. In addition to Windows and Mac desktop apps, there are mobile keyboards for iOS and Android, and a web editor. Browser extensions are available for Chrome, Safari, Firefox and Edge. It integrates with Microsoft Office on Windows and Mac. Google Docs support was recently added.

All this power doesn‘t come cheap. Grammarly Premium (needed to unlock all features) costs $139.95/year at full price, more than most competitors. But Grammarly frequently offers significant discounts and has a strong free plan. If you want the best possible automated proofreader in your corner, it‘s worth the price.

Best Runner-Up: ProWritingAid

ProWritingAid is a close rival to Grammarly with a robust set of features for a lower price. Its spelling and grammar checking is nearly as strong as Grammarly‘s. Like Grammarly, it provides comprehensive feedback on writing style and readability.

ProWritingAid distinguished itself in our testing with its detailed writing reports. You can analyze your document for a wide variety of stats: readability measures, overused and repeated words, diction, sticky sentences, cliches and more. The level of reporting goes beyond most competitors.

Another ProWritingAid strength is integrations. In addition to Google Docs, Microsoft Office, and Scrivener support, it offers a WordPress plugin and an API. The desktop app is a bit less polished than Grammarly‘s but capable.

A ProWritingAid Premium subscription costs $79/year, making it significantly more affordable than Grammarly. Plagiarism checking does cost extra but is reasonable if used in moderation. ProWritingAid offers less device support (no mobile keyboards or Safari extension), and its free plan is limited. But its powerful features and attractive price make it a strong alternative.

Other Grammar Checkers to Consider

A few other grammar tools offer compelling features for specific use cases:

Ginger is the best grammar checker with mobile apps for iOS and Android (most only offer mobile keyboards). However, its grammar checking was less reliable than Grammarly or ProWritingAid in our tests.

WhiteSmoke has a solid spelling and grammar checking engine at an affordable price. Its desktop apps feel somewhat dated, and some features like plagiarism detection are limited. But it provides good bang for the buck.

LanguageTool is a capable, multi-language grammar checker with an open source heritage. While not as feature-rich as some commercial tools, it supports over 20 languages, more than any other tool we looked at.

GradeProof (formerly Outwrite) offers just the basics – a Chrome extension and MS Office/Google Docs integration – but its grammar checking was solid in our tests. GradeProof tries to distinguish itself with customized student feedback but has some usability rough edges.

Free Grammar Checkers

If your needs are basic, free online grammar checkers can handle simple spelling and grammar checking. Tools like Scribens, Virtual Writing Tutor, and SpellCheckPlus provide solid results for no cost. For more comprehensive feedback, consider Hemingway Editor, a free web app for evaluating readability.

Your word processor‘s built-in checker may also suffice for basic use. Microsoft Editor in Word and Google Docs‘ spelling and grammar check have improved significantly. They‘re not as full-featured as premium tools but are suitable for casual writing.

Grammar Checker Testing Methodology

To evaluate each tool, we devised a set of test sentences containing intentional errors, including:

• Spelling mistakes like "errow"
• Correctly spelled words used incorrectly, like "less" vs "fewer"
• Subject-verb disagreement
• Punctuation errors
  We checked how many errors each tool successfully flagged.

We also ran several full documents through each checker to get real-world experience. We judged the tools on ease of use and helpfulness of feedback.

Finally, we inventoried each tool‘s supported platforms, integrations, and key features. We considered pricing and discounts to determine the overall value.

Final Thoughts

Running your writing through a grammar checker is one of the best ways to eliminate errors and communicate clearly. While no automated tool is perfect, the best grammar checkers can make a meaningful difference in your writing.

Our overall recommendation is Grammarly for its unmatched combination of accuracy, features, and polish. ProWritingAid is a strong alternative at a lower price. Writers and students on a budget should consider WhiteSmoke or GingerPro.

For additional insights on improving your writing, check out our other reviews of the best writing software, including the top writing apps and book writing software.

With the help of a trusty grammar checker and the right tools, you‘ll be able to express yourself masterfully in writing. Here‘s to mistake-free writing ahead!