ripgrep author here. The main user-facing difference is that ripgrep will automatically skip searching certain files: files in your gitignore, hidden files, and binary files. grep will by default try to search everything.

The primary reason for this isn’t necessarily performance, although it does occasionally help with that. The primary reason is to improve the signal-to-noise ratio of results. Of course, ‘rg -uuu …‘ can be used, and this will disable all such “smart” filtering.

@Alvaro,

The main difference is that ripgrep is faster than grep and most of grep’s features are implemented in ripgrep. They include full Unicode support, color highlighting on search matches, multiple patterns searches, and search results context display.