Pino vs Bunyan

Pino and Bunyan take two different approaches to logging in Node.js. Each library handles application logs and debugging information differently in production environments.

Bunyan offers structured logging with lots of features. It uses JSON-based logging with comprehensive tools that many developers use in enterprise applications.

Pino focuses on speed and performance. It keeps the structured logging that made Bunyan popular but runs much faster.

This guide explains how these libraries differ, how they perform, and when you should use each one for your Node.js projects.

What is Bunyan?

Bunyan creates structured logs with rich features. It makes JSON-based log records that you can easily parse and analyze. Trent Mick created it to handle complex objects, errors, and HTTP requests automatically.

The library uses hierarchical loggers with different output destinations. You can send logs to various systems and route different log levels to different places. This helps you maintain context across distributed systems.

Bunyan focuses on making developers productive with built-in tools. It includes a command-line interface for parsing and formatting logs. Its mature ecosystem and detailed documentation make it a solid choice when you need robust logging.

What is Pino?

Pino puts performance first in structured logging. Matteo Collina and the Node.js community built it to minimize the overhead that usually comes with comprehensive logging solutions.

The library's main innovation is asynchronous logging. It separates log writing from formatting, so your application keeps running while log data gets processed separately. This design puts minimal runtime impact over immediate log formatting.

Pino's ecosystem includes specialized tools for processing and analyzing logs. These tools work together to give you comprehensive observability without slowing down your application. Its modular design lets you customize the logging pipeline while keeping it fast.

Pino vs. Bunyan: a quick comparison

The main difference between these libraries is how they balance performance against features and how they handle log processing.

You need to understand these differences to make good architectural decisions:

Architecture and design philosophy

Pino and Bunyan use different approaches to logging system design. This affects everything from how fast they run to how complex they are to operate.

Bunyan uses a synchronous logging model. It processes logs immediately within your application thread. This gives you immediate feedback and comprehensive formatting:

const bunyan = require('bunyan');

const logger = bunyan.createLogger({
  name: 'myapp',
  streams: [
    { level: 'info', stream: process.stdout },
    { level: 'error', path: '/var/log/error.log' }
  ]
});

logger.info({ userId: 123 }, 'User logged in');

This synchronous approach formats logs immediately but can slow down your application during heavy logging.

Pino uses asynchronous logging architecture. It reduces application thread blocking by handling formatting in separate workers:

const pino = require('pino');

const transport = pino.transport({
  target: 'pino/file',
  options: { destination: '/var/log/app.log' }
});

const logger = pino({}, transport);
logger.info({ userId: 123 }, 'User logged in');

Pino separates log generation from processing. Your application stays fast while comprehensive analysis happens in background processes.

Performance characteristics

Performance differences between these libraries can significantly impact how fast your application runs, especially when you log frequently.

Bunyan's synchronous processing gives you predictable performance with consistent overhead for each log operation:

const bunyan = require('bunyan');
const logger = bunyan.createLogger({ name: 'benchmark' });

console.time('bunyan-logs');
for (let i = 0; i < 1000; i++) {
  logger.info({ iteration: i }, 'Log entry');
}
console.timeEnd('bunyan-logs');
// Typical result: ~45ms

Pino's asynchronous architecture gives you better performance by spending less time in your application thread:

const pino = require('pino');
const logger = pino({}, pino.destination('/dev/null'));

console.time('pino-logs');
for (let i = 0; i < 1000; i++) {
  logger.info({ iteration: i }, 'Log entry');
}
console.timeEnd('pino-logs');
// Typical result: ~8ms

Pino consistently runs 3-5x faster than Bunyan in throughput benchmarks. This makes it good for situations where you log frequently.

Feature comparison and capabilities

These libraries have different feature sets that reflect their design philosophies. Bunyan emphasizes built-in capabilities while Pino focuses on extensible performance.

Bunyan gives you extensive built-in functionality without needing additional dependencies:

const bunyan = require('bunyan');

const logger = bunyan.createLogger({
  name: 'app',
  serializers: bunyan.stdSerializers,
  streams: [
    { level: 'info', stream: process.stdout },
    { 
      level: 'error', 
      type: 'rotating-file',
      path: '/var/log/app.log',
      period: '1d'
    }
  ]
});

logger.error({ err: new Error('Failed') }, 'Error occurred');

Pino achieves similar functionality through modular plugins and transport systems:

const pino = require('pino');

const transport = pino.transport({
  targets: [
    { target: 'pino/file', options: { destination: 1 } },
    { target: 'pino/file', options: { destination: '/var/log/app.log' } }
  ]
});

const logger = pino({ serializers: pino.stdSerializers }, transport);
logger.error({ err: new Error('Failed') }, 'Error occurred');

Pino's modular approach keeps performance high while giving you comprehensive features through external tools.

Development experience and tooling

The development experience differs between these libraries based on their architectural approaches and target use cases.

Bunyan gives you integrated tooling that works right after you install it:

# Pretty-print logs
node app.js | bunyan

# Filter by level
node app.js | bunyan -l warn

# Search logs
node app.js | bunyan -c 'this.user'

Pino's development experience focuses on performance in production while giving you excellent debugging through specialized tools:

# Development with pretty printing
node app.js | pino-pretty

# Production logging with post-processing
node app.js > app.log
cat app.log | pino-pretty --colorize

Pino's tooling ecosystem separates runtime performance from log analysis. This lets you get optimal performance in production while keeping debugging capabilities.

Production deployment considerations

Deployment characteristics and operational requirements differ between these logging approaches. This affects performance monitoring and troubleshooting capabilities.

Bunyan's synchronous model gives you immediate log availability but you need to consider performance impact in high-traffic applications:

const logger = bunyan.createLogger({
  name: 'production-app',
  level: process.env.LOG_LEVEL || 'info',
  streams: [
    { level: 'info', stream: process.stdout },
    { level: 'error', path: '/var/log/error.log' }
  ]
});

Pino's asynchronous architecture optimizes for production performance while maintaining comprehensive logging through background processing:

const transport = pino.transport({
  targets: [
    { target: 'pino/file', options: { destination: 1 } },
    { target: 'pino/file', options: { destination: '/var/log/error.log', level: 'error' } }
  ]
});

const logger = pino({ level: process.env.LOG_LEVEL || 'info' }, transport);

Pino's architecture minimizes impact on your application while ensuring comprehensive log data reaches monitoring systems.

Final thoughts

This comprehensive analysis of Pino and Bunyan shows you two mature approaches to structured logging in Node.js applications.

If you're undecided, Pino is the better choice for most modern applications due to its superior performance and flexible architecture that adapts well to current development practices and deployment environments.

Got an article suggestion? Let us know

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.