Pino Logger

Pino is a very low overhead Node.js logger designed for maximum performance in high-throughput production environments, consistently ranking as the fastest logging library in the Node.js ecosystem across independent benchmarks. The core design philosophy separates log generation from log processing by writing newline-delimited JSON to the destination stream synchronously in a single write call, then deferring all expensive formatting, transport, and filtering work to worker threads or separate processes. This approach achieves throughput rates exceeding 50,000 log lines per second on commodity hardware while adding less than 10 percent overhead to request latency compared to applications with no logging at all. The logger produces structured JSON output with configurable log levels of fatal, error, warn, info, debug, and trace, supporting child loggers with bound context for request-scoped tracing across microservices. The transport architecture supports multiple destinations through pino transports including file rotation, HTTP streaming to log aggregation services, Kafka publishing, Elasticsearch indexing, Sentry error forwarding, and custom transport modules running in worker threads. The pretty-print transport provides human-readable colorized output for development with configurable timestamp formats and message formatting. The extreme mode bypasses Node.js streams entirely by using direct file system writes with fs.writeSync for maximum throughput at the cost of buffering safety. Built-in serializers handle common Node.js objects including HTTP request and response objects, error objects with stack traces, and process information. The browser variant provides the same API for isomorphic applications with console output and batching. Integration with frameworks including Express, Fastify, Hapi, and Nest.js is documented with best practices. Created by Matteo Collina and maintained by the Pino.js organization. MIT licensed. Copyright 2016-2026 Pino Contributors.