Sharepoint Designer 2010 Today
For any new development, migrate to , SharePoint Framework (SPFx) , or Visual Studio 2012/2013 with SharePoint Add-ins .
Advanced users can customize master pages (e.g., v4.master ), page layouts, and CSS files. The tool provides a (Code + Design view), making it possible to tweak branding without needing Visual Studio. Note: Using SPD on production master pages requires caution, as errors can break site rendering. sharepoint designer 2010