If you're searching across a bunch of open-source repos, Grep.app can be super handy—it’s fast, supports regex well, and lets you filter by language and license. But if you’re focused on a specific GitHub repo, GitHub’s native search is probably better. It ties in with commit history, issues, and PRs, and the new symbol search is great for navigating large codebases. Basically, Grep.app is good for broad searches across projects, while GitHub search is stronger for digging deep into one project.