Pino
Extremely fast Node.js JSON logger — benchmarks show 5-10x faster than Winston and Bunyan. Uses a worker thread for serialization to minimize impact on application code. Outputs newline-delimited JSON (NDJSON) optimized for log aggregation systems. Default logger for Fastify framework. Supports child loggers with bound metadata, log levels, and a rich plugin ecosystem (pino-pretty for development, pino-http for HTTP logging).
Score Breakdown
⚙ Agent Friendliness
🔒 Security
MIT licensed. Redaction support via redact option: pino({ redact: ['req.headers.authorization'] }) — built-in PII/secret redaction in log output.
⚡ Reliability
Best When
You're building high-performance Node.js services (especially with Fastify) that need structured JSON logging with minimal overhead.
Avoid When
You need multiple simultaneous transports, complex in-process formatting, or are building applications where logging API ergonomics matter more than throughput.
Use Cases
- • High-throughput agent API logging where logging overhead must be minimized for maximum request throughput
- • Structured JSON logging in Fastify-based agent services with request ID correlation via pino-http
- • Kubernetes/cloud-native logging pipeline where NDJSON output feeds directly into Fluentd or log aggregators
- • Child logger per request for automatic metadata binding (requestId, userId, traceId) in agent microservices
- • Production logging with pino-pretty for human-readable development output and raw NDJSON for production
Not For
- • Browser logging — pino is Node.js only (pino-browser exists but limited)
- • Multiple simultaneous log destinations — pino writes to a single stream; use pino-multi-stream or a log aggregator for multiple sinks
- • Complex custom log formatting in-process — pino's philosophy is minimal in-process work; formatting is done by downstream tools
Interface
Authentication
Local library — no authentication required. MIT licensed.
Pricing
MIT licensed. Zero cost.
Agent Metadata
Known Gotchas
- ⚠ Pino v7+ uses async transports via worker threads — transport configuration changed; use transport option instead of stream piping for v7+ transports
- ⚠ pino-pretty should NOT be used in production — it's 3-5x slower; use it for development only via NODE_ENV check or CLI pipe: node app.js | pino-pretty
- ⚠ Child loggers are the recommended pattern for request-scoped metadata: const reqLogger = logger.child({ requestId: req.id }) — create per-request, don't modify parent logger
- ⚠ Circular reference detection is off by default for performance — objects with circular references will throw; use serializers to handle complex objects: logger.child({ serializers: pino.stdSerializers })
- ⚠ Log level filtering: pino only logs at and above the configured level — debug level logs are zero-cost when level is 'info' (not even serialized)
- ⚠ pino's output is NDJSON with epoch millisecond timestamps — pino-pretty or log aggregators handle display; epoch timestamps require conversion for human reading
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for Pino.
Scores are editorial opinions as of 2026-03-06.