How Google Docs grammar check compares to its alternatives

G Suite Basic, Business, and Enterprise users can now check grammar in Google Docs. Here's a quick look at how well the feature performs compared to alternatives.

G Suite: What is it, and how can it benefit businesses?

Google Docs offers grammar and spelling suggestions in G Suite Basic, Business, and Enterprise editions. When the features are enabled, a red line under a word indicates a possible spelling error, while a blue line below a word signals a potential grammar problem.

SEE: G Suite: Tips and tricks for business professionals (free PDF) (TechRepublic)

To enable the options for Google Docs in a browser, go to Tools | Spelling And Grammar and make sure there's a check next to Show Spelling Suggestions and/or Show Grammar Suggestions. Use the Tools | Spelling And Grammar | Spelling And Grammar Check option to review each suggestion made by the system (Figure A).

Figure A

Screenshot of Tools > Spelling and grammar check menus in Google Docs for G Suite

Grammar check in Google Docs is now available in G Suite Basic, Business, and Enterprise editions.

Once spelling and grammar check options have been enabled for a document, the system will display the red or blue line indicators within a Google Doc in a desktop/laptop Chrome browser or Google Docs mobile apps for Android or iOS.

Google has offered spelling suggestions in Google Docs for several years. When a word in your document doesn't correspond with any dictionary word, it may be flagged. You may add words to your own personal dictionary to prevent the system from marking a word as a problem; to do so, go to Tools | Spelling And Grammar | Personal Dictionary. You can add a company name, a product code, or other specialized language to your personal dictionary.

Google released grammar check for Google Docs in March 2019. The company's blog post announcing the feature said that the system would be "using machine translation techniques to help you catch tricky grammatical errors . . . with grammar suggestions in Docs."

To demonstrate, I've written six sentences that include seven errors, marked below. A quick count might reveal six errors--the seventh error is the lack of punctuation after the word "gooder" (Figure B).

The Chromebook are turned on.

Google Docs now checks speling and grammar.

This document contain errors.

It should get gooder

My tests indicate that the system does not yet perform as well as I would like it too work.

Grammar checking be difficult.

Figure B

Screenshot showing test text included in article, with handwritten proofreading markings that indicate corrections to the 7 errors in the text.

Note that these are short, simple sentences. Business documents, such as contracts and reports, might include longer sentences and contain more complex language. I intentionally kept this test simple.

I tested the above text using several different grammar check systems to see how they compared to the grammar check feature in Google Docs. Below are the results:

Google Docs grammar check

The Google Docs spelling and grammar check system suggested only two corrections: "Speling" to "spelling" and "contain" to "contains" (Figure C).

Figure C

Screenshot showing the word "speling" underlined in red (spelling error), and word "contain" underlined in blue (grammar error)

The Google Docs spelling and grammar check system only found two out of seven errors.


Grammarly identified issues with six of the seven errors (Figure D). The one it missed? The lack of punctuation at the end of the sentence "It should get gooder," which obviously needs a punctuation/termination mark, such as a period.

Figure D

Screenshot of with all sample errors underlined in red. But no error indicated at the end of the sentence missing a period.

Grammarly found six out of seven errors.

For this test, I used the paid version of Grammarly, which costs about $140 per year. The service offers a Chrome extension, a web-based app, and a keyboard app for Android and iOS devices.

Sapling also caught six of the seven problems--the only one it missed was the need for punctuation to terminate a sentence (Figure E).

Figure E

Screenshot of Chrome extension with errors indicated.

Sapling found six out of seven errors.

Sapling Assist is free and offers a Chrome extension and a Google Docs add-on. A pro version offers more suggestions and additional integrations for $25 per month, per person.


I pasted the tester text into Ginger's web-based grammar checker, and it located five of the seven errors. The tool missed the subject-verb agreement problem with "Chromebooks are" and also failed to identify the need for punctuation at the end of a sentence (Figure F).

Figure F

Screenshot of Ginger Writer, showing a mix of red and blue highlighted words to indicate errors.

Ginger found five out of seven errors.

The Google Chrome extension and web-based grammar checker are free. The company also offers mobile apps for Android ($6.49) and iOS ($4.99), among other options. The premium edition is $90 per year.


Scribens found four of the seven issues--it identified the need for punctuation but found the word "gooder" acceptable. It flagged "Chromebook" as a word not in the dictionary, but didn't identify that the phrase "Chromebook are" includes a singular subject with a plural verb (Figure G).

Figure G

Screenshot of Scribens, with errors indicated in red, green, and blue colors.

Scribens found four out of seven errors.

Scribens is a free service that works either with text you paste into the service's website, or with a Google Docs add-on.


LanguageTool caught three problems: The word "speling," the improper use of "contain," and "gooder," (Figure H).

Figure H

Screenshot of, showing errors indicate with red and yellow highlights.

LanguageTool found three out of seven errors.

The LanguageTool website service, Chrome extension, and Google Docs add-on are all free. The paid version offers enhanced detection for $59 per year.

Suggested system?

For Google Docs users, the addition of a grammar check system will no doubt help identify and correct errors. My tests indicate that the system--even with its touted use of "machine translation" and "AI"--does not yet perform as well as I would expect.

I recommend that every Google Docs user turn on both the spelling and grammar check features. As of early April 2019, third-party grammar check systems may deliver better suggestions, although access to some of those systems and analyses may come at an additional cost. [Author's note: Of course, the best system might be a human editor, but I may be biased.]

If you use G Suite Basic, Business, or Enterprise, how well does the Google Docs spelling and grammar check system work for you? If you use other automated proofreading systems, which ones perform best for your needs? Let me know what your experience with grammar checking systems has been, either in the comments below or on Twitter (@awolber).

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