Learn about the Spell Checker

Many of the features in Visual Studio are designed to help you write the code you want, from making sure that your code compiles to helping you with code styling. Now, with the Spell Checker feature—introduced in version 17.5—Visual Studio can even make sure your spelling is accurate.

The Spell Checker is available for any C#, C++, or Markdown file. When the Spell Checker is enabled, Visual Studio marks any words that it detects as misspelled words. Visual Studio also suggests alternate spellings and helps correct them. The feature even does a contextual rename when those misspellings are identifiers so that your code still compiles.

You can turn the spell checker off or on by using the Toggle Spell Checker button on the main toolbar, or by selecting Edit > Advanced > Toggle Spell Checker command from the menu bar.

How do you use it?

When the caret is on a spelling error, the Quick Actions provide solutions for fixing the spelling mistakes. You can bring up the Quick Actions by using the keyboard shortcuts Ctrl+. or Alt+Enter. When the context menu comes up, Visual Studio displays three options to handle a spelling issue.

If any of the dictionaries provide spelling suggestions, Visual Studio displays them. If multiple dictionaries provide suggestions, Visual Studio groups its suggestions by dictionary. For strings and comments, choosing one of these suggestions results in a single, in-place replacement. For identifiers in a C++ or a C# document, accepting a suggestion results in a Refactor/Rename that updates all instances of the identifier to make sure the code compiles.

You can also choose to ignore the spelling issue. By choosing to ignore the issue, Visual Studio creates an exclusion.dic file in your AppData directory on your local machine. After you choose to ignore a word, the spelling checker ignores it across all instances of Visual Studio.

How does it work?

Because C#, C++, and Markdown all use English as the language for their keywords, Visual Studio typically uses the "English (United States)" or "en-us" dictionary for spell checking. Visual Studio checks the instance of Windows for the display language it's using, and if it's not "en-us", it uses that dictionary as well.

Note

C# and C++ also have additional dictionaries for keywords in those languages, which prevents words like ‘namespace’ or ‘alloc’ from being flagged as misspelled words.

Feedback from early users of this feature informed us that developers only want to know about errors in the document they are currently working with. In response to that feedback, the spell checker only scans the document(s) that are active in the editor. In direct response to this feedback, the spell checker scans documents that are open.

The following table shows some of the heuristics that the Spell Checker looks at when it scans a code document:

What's in the code	What Visual Studio checks	Why?
Hello	Hello, hello	Always check for both proper and common nouns
HelloWorld	Hello, hello, World, world	Medial capitals are used to mark word boundaries
Hello.World	Hello, hello, World, world	Punctuation is used as a word boundary
_Hello123	Hello, hello	Leading or trailing numbers or punctuation marks are stripped
Hello2World	Hello, hello, World, world	Medial numbers, like punctuation marks, are used as word boundary
btnWorld	World, world	Fragments of three characters or fewer are ignored
helloworld	Helloworld, helloworld	No indicator to identify word boundaries

If Visual Studio finds a match for the token in any of the dictionaries it's using, the token is considered acceptable and the scan carries on. Otherwise, the token is considered misspelled and Visual Studio flags it as a spelling error.

How to customize the Spell Checker

You can customize the spell checker so that it's optimized for a collaborative environment. As such, Visual Studio uses an EditorConfig file for configuration so that you can control the spell checker behavior in a repository.

By configuring an EditorConfig file, you can establish the coding standards that you expect everyone to follow, which allows you to maintain a coding consistency that might be difficult through other methods.

Here are some examples and use-case scenarios of the switches you can configure in an EditorConfig file:

• List the languages for Visual Studio to use. In this example, Visual Studio would only use the "en-us" and "fr-fr" dictionaries when checking for spelling issues.

  spelling_languages = _language_[,_language_]
(Example: = en-us,fr-fr)

  Note

  Make sure to install the language pack for any language you're using to prevent Visual Studio from incorrectly flagging words as spelling errors.

• Control what Visual Studio should check. In this example, Visual Studio would check identifiers and comments for misspelled words but wouldn’t check inside strings.

  spelling_checkable_types = strings,identifiers,comments
(Example: = identifiers,comments)

• Control the severity Visual Studio assigns to spelling errors in the error list. In this example, spelling errors are displayed as errors.

  spelling_error_severity = error OR warning OR information OR hint
(Example: = error)

• Create your own exclusion dictionary to specify words you consider to be correctly spelled. In this example, the first time the Spell Checker is run against any file in the solution, Visual Studio checks for an exclusion.dic file in the same directory as the .sln file (for a C# project) or in the root directory (for a C++ directory). If no exclusion.dic file exists, the Visual Studio creates one. Then, whenever the user chooses to ignore a word, Visual Studio adds it to this exclusion.dic file. Visual Studio considers any word that appears in this exclusion.dic file as a correctly spelled word.

  spelling_exclusion_path = absolute OR relative path to exclusion dictionary
(Example: = .\exclusion.dic)

  Note

  Visual Studio uses the exclusion dictionary specified by the spelling_exclusion_path switch in your .editorconfig file or an exclusion.dic file in your %localappdata%\Microsoft\VisualStudio\<Version> directory if a switch can’t be found.

• Control whether the language-specific exclusion dictionary so use. When set to false, any words specified in the exclusion dictionaries specific to C++ or C# won't be used. The default is true.

  spelling_use_default_exclusion_dictionary = true OR false
(Example: = spelling_use_default_exclusion_dictionary = false)

Special case handling

There are a few special behaviors in how Visual Studio checks code for spelling errors that are different from a traditional spell checker that's designed for written text. Some of these behaviors include:

• In a string that includes punctuation, for example, 'misc.", Visual Studio won't suggest a correction because punctuation in an identifier might result in code that won't compile.
• Backslashes in a string will omit the subsequent character from being spell-checked and treat the backslash and subsequent character as a word delimiter. For example, in the string hello\nworld, Visual Studio detects the backslash first. Visual Studio treats the \n as a word delimiter, which leaves "hello" and "world", each of which are checked individually.
• Strings that contain URLs such as https://... or mailto:.. won't be spell-checked over the entire string.

Related content

• Improving the Spell Checker