The Formatting Nightmare
Google Docs tries to maintain a consistent visual style throughout your document. If you have been typing in 11pt Arial, and you suddenly paste a paragraph of text copied from a website that uses 18pt Times New Roman, Docs will often insert the text exactly as it was formatted on the web. Worse, if you then click at the end of that pasted paragraph and hit Enter to continue typing, Docs will automatically change the font size of your new, original text to match the massive 18pt font you just pasted, forcing you to constantly stop and manually adjust the font drop-down menu.
Stripping the Styles
To maintain your intended layout and stop Google Docs from automatically changing the font size to match pasted content, you must change how you insert text or aggressively clear formatting.
The absolute best practice to prevent this issue is to stop using the standard Paste command. When copying text from an external source, return to Google Docs and press Ctrl+Shift+V (Windows/Linux) or Command+Shift+V (Mac). This command executes a “Paste without formatting.” It strips away the font size, color, and typeface of the original source, forcing the pasted text to instantly adapt to whatever font size your cursor was currently using. If the text is already in the document and the formatting is ruined, highlight the offending paragraph and navigate to the top menu bar. Click on Format and select Clear formatting (or press Ctrl+\). This instantly reverts the highlighted block to your document’s default ‘Normal text’ style.