Spellchecking software can be helpful when copyediting Wikipedia articles. This page explains how to use it well and avoid conflicts with other editors.

General advice:

• Be sure to use the spelling for the correct dialect of a language (e.g., American English vs. British English).
• No spellchecker is completely accurate.
• Be extremely careful when editing pages written in languages in which you are not fluent.
• Grammar-checking tools can introduce more errors than they appear to fix.
• You are responsible for all spelling or grammar changes you make, even if the corrections were suggested by an error-checking tool.

Be careful about setting the language of the software to the correct variety of English. If the article's topic is not linked to a particular region, use the same variety as the first non-stub version of the article. Check the talk page before editing variety-specific spelling; many articles have a template such as {{Use Hiberno-English}} near the top of its talk page that indicates the spelling to be used.

Use the article's variant consistently throughout the article (except in direct quotations), and use terms that are common to all varieties of English (e.g., fixed-wing aircraft rather than airplane or aeroplane) whenever possible.

See Wikipedia:Manual of Style § National varieties of English for detailed advice, and Wikipedia:Manual of Style/Spelling for a table of spelling variants in different dialects.

Using a web browser[edit]

The easiest way to spellcheck a single article is to use the built-in spellcheck of your web browser.

• Mozilla Firefox has a built-in spellchecking engine. However, you should check that the right dictionary for your language is installed and selected. Right-click in an editing field, make sure that "Check spelling" is checked, then under "Languages" select the right language. There are separate dictionaries for "English / United States", "English / United Kingdom" etc.; if the right dictionary does not appear in the list, click "Add Dictionaries" and use the page that appears to install it (note that you will have to restart Firefox to enable it after installing).
• Google Chrome provides built-in spellchecking for each text field.^[1]
• Microsoft Edge also has a built-in spellchecker.
• Safari also provides spellchecking features on Mac.
• Opera has a spellchecker.^[2]

Browser extensions[edit]

• Grammarly is a free plugin for popular web browsers that checks not only spelling, but also grammar, usage and punctuation.
• LanguageTool is an open-source tool that checks grammar and spelling.

Using an external website[edit]

• SpellChecker.org is a free online spellchecker that requires no extension or add-on installation.
• WebSpellChecker is a multi-language spellchecking engine that can be integrated into a website or a web application.

Using word-processor software[edit]

Many office suites, such as Microsoft Office and LibreOffice, are equipped with spell and grammar checkers that are on by default. Open the Wikipedia article, select "edit" from the menu atop the page or section, select and copy the article source, paste it into a Word or Writer document, follow the red (spelling) and green (grammar) markers, and correct mistakes as necessary.

To enable spellchecking in Microsoft Word, go to the Tools menu and enable "Grammar and spellchecking". When satisfied, copy and paste the text into the text box in the browser window, check that any UTF-8 characters are still working as before by clicking "Show changes", and, if satisfied, click "Publish changes", as usual.

In LibreOffice Writer, go to the top menu, select "Tools" → "AutoCorrect", and select "while typing" to enable checking.

If you have installed the anti-vandal tool in your common.js, you can use the live spellcheck to identify misspellings as they happen (recent edits). This is not a comprehensive spellcheck — it points out only the most commonly misspelt words. And it will not spellcheck text that an editor is adding to an article (for that, see the web browsers section, above).

Wikipedia:Spellcheck dictionary is an editor-compiled list of English words, terms, abbreviations and acronyms commonly encountered on Wikipedia. You may copy it and add it to your software's spell-check dictionary.