Benchmark: running regex, substring for at least 2 CPU seconds... regex: 1 wallclock secs ( 2.09 usr + 0.00 sys = 2.09 CPU) @ 14030.14/s (n=29323) substring: 3 wallclock secs ( 2.14 usr + 0.00 sys = 2.14 CPU) @ 23225.70/s (n=49703) Rate regex substring regex 14030/s -- -40% substring 23226/s 66% --