GitHub’s built-in search is way better than most people realize. Just use the search bar and add qualifiers like filename:*.js your_search_term for JavaScript files only, or path:src/ your_pattern for specific directories. It even supports regex for pattern matching. I’ve used this for two years when auditing code - beats cloning repos every time. Works great on public repos and smaller private ones. For complex searches across multiple repos, try GitHub’s REST API with a quick script, but honestly the web search handles most stuff just fine.