Free Online Grammar Checker

Updated July 30, 2020

Can a grammar checker really help improve your writing? While they may sound like a wonderful idea, grammar checking programs have several limitations.

About Grammar Checkers

In theory, a computer-based grammar checker should work like a spell checker. It should identify errors and suggest alternatives for corrected text. However, spelling is fairly straightforward. In comparison, grammar is more much interpretive.

Despite recent advances in computer technology, it is very difficult for a machine to learn to properly understand the English language. In written English, there are a number of expressions that have multiple meanings and the context of a word's usage can directly affect the tone of a sentence. These subtleties are simply impossible for a machine to fully comprehend, thus leaving grammar checkers with three main flaws:

  • A grammar checker may miss important errors.
  • A grammar checker may accidentally suggest corrections that are inaccurate.
  • A grammar checker may flag grammatically correct text as incorrect.

There are many common grammar errors that computer software struggles to find. For example, one recent study comparing the effectiveness of common grammar checkers found that these programs will typically miss the following errors:

  • No comma after an introductory element in a sentence
  • Missing preposition
  • Comma splice
  • No comma in a compound sentence
  • Vague pronoun references
  • Tense shift
  • Incorrect use of the possessive apostrophe
  • Pronoun agreement error
  • Run-on sentence
  • Sentence fragment

If you're truly interested in learning to improve your grammar, it's best not to rely on software to catch your errors. Instead, brush up on basic grammar rules and common errors by visiting the grammar rules section here on Your Dictionary.


Free Online Grammar Checkers

While it's true that grammar checking software has many limitations, using a free online grammar checker can be useful in certain circumstances. For example, students who are learning English as a second language may find that online grammar checkers help them learn to more easily spot errors in their writing.

If you are looking for free online grammar checkers, consider one of the following resources:

  • lets you copy and paste text into an online tool to quickly identify spelling and grammar errors. An online thesaurus is also available for your convenience.
  • AbiWord is a free open source word processing program that includes a grammar checker. It is supported on all of the most common operating systems, including Linux, Mac OS X (PowerPC), and Microsoft Windows. The interface is similar to Microsoft Word, making this program very easy to use. Import and export filters let you convert documents to HTML, Rich Text Format, and OpenDocument for greater convenience.
  • LanguageTool is a free open source grammar checker that is designed to help users identify the most common grammatical mistakes in their text. Language Tool works to detect errors in English, German, Dutch, and Polish, but limited support is also available for French, Spanish and Italian.

Microsoft Word Grammar Checker

If you're looking for an online grammar checker, you may be surprised to learn that Microsoft Word's spell checker can also be used to find common grammatical mistakes. If you have this popular word processing program on your computer, check out the following links to learn how to take advantage of the grammar check feature:

Remember, a grammar checker is not a substitute for learning good is only a double check that you followed the correct grammar rules.