Defined in header <Kokkos_Printf.hpp> which is included from <Kokkos_Core.hpp>

template <typename... Args>
KOKKOS_FUNCTION void printf(const char* format, Args... args);  // (since 4.2)

Prints the data specified in format and args... to stdout. The behavior is analogous to std::printf, but the return type is void to ensure a consistent behavior across backends.


#include <Kokkos_Core.hpp>

int main(int argc, char* argv[]) {
    Kokkos::initialize(argc, argv);
    Kokkos::parallel_for(4, KOKKOS_LAMBDA(int i) {
        Kokkos::printf("hello world from thread %d\n", i);


  • The Kokkos::printf() function was added in release 4.2

  • Calling Kokkos::printf() from a kernel may affect register usage and affect performance.