pino
Super fast, all natural json logger
...Over time, logged messages tend to pile up. This can lead to some negative effects on applications, such as reduced requests per second. This is why pino is an ideal choice for logging. pino is a very fast Node.js logger with very low overhead. It is in many cases 5x faster than alternatives, based on benchmarks.
pino offers not just speed but a number of great features as well, such as a browser API, child loggers, transports, and pretty printing, which "prettifies" your logs.