Spellcast Style Checker is a formatting and style checker designed to automate the repetitive parts of proofreading directly inside Google Docs™. Standard spelling checkers catch spelling mistakes, but they do not address structural or typographic consistency. Spellcast brings style guide checks and glossary audits directly into your workspace.

The add-on runs entirely client-side inside your document sandbox, ensuring your document contents remain private. Spellcast handles formatting basics automatically: checking defined terms for styling consistency, flagging uncapitalised key terms, keeping punctuation formatting consistent, identifying unused glossary definitions, keeping headings and lists attached across page breaks, and highlighting bracketed placeholders, drafting marks, or numeric discrepancies.

The tool automatically reads your file's own formatting to detect document-wide style rules—such as smart versus straight quotes, or sentence versus title case headings—and surfaces the exceptions. You can also manually configure your own preferences to override the document's majority style. Review findings grouped by category in the sidebar, click cards to jump straight to the source, and apply fixes in seconds.