Logging for TypeScript: Best Solutions

Logging is a critical component of any production application. For the TypeScript ecosystem, there are many libraries, each offering a unique set of features. In this article, we will look at five best solutions: Winston, Pino, Bunyan, Log4js, and TSLog. You will learn their strengths, configuration specifics, and get ready-made code examples.

1. Winston — The Universal Standard

Winston is the most popular logging library for Node.js with full TypeScript support. It provides a powerful system of transports (where to send logs) and formatting.

import winston from 'winston';

const logger = winston.createLogger({  level: 'info',  format: winston.format.combine(    winston.format.timestamp(),    winston.format.json()  ),  transports: [    new winston.transports.Console(),    new winston.transports.File({ filename: 'error.log', level: 'error' })  ]});

logger.info('Application started', { service: 'user-service' });logger.error('Database connection error', { error: err.message });

Advantages:

Flexible transport system (files, console, HTTP, MongoDB, Elasticsearch)
Built-in log rotation support via winston-daily-rotate-file
Excellent TypeScript integration — full typing
Compatibility with profilers and APM systems

2. Pino — Ultra-Fast Logger

Pino is performance-oriented — it is 5-10 times faster than Winston. An ideal choice for high-load systems and microservices.

import pino from 'pino';

const logger = pino({  level: process.env.LOG_LEVEL || 'info',  transport: {    target: 'pino-pretty',    options: { colorize: true }  }});

logger.info({ user: { id: 123 } }, 'User authorized');

Key Features:

Minimal CPU and memory consumption
Native support for Node.js streams
Efficient object serialization
Support for child loggers for contextual logging

3. Bunyan — Structured Logging from Joyent

Bunyan was created for working with microservice architecture. All logs are output in JSON format, simplifying their parsing and analysis.

import bunyan from 'bunyan';

const logger = bunyan.createLogger({  name: 'myapp',  level: 'info',  serializers: {    req: bunyan.stdSerializers.req,    err: bunyan.stdSerializers.err  }});

logger.info({ req: request }, 'Incoming request');

Features:

Built-in serializers for HTTP requests and errors
Support for ringbuffer to store the last N records
Bunyan CLI utility for formatted console output
Easy integration with the ELK stack

4. Log4js — Familiar Approach from Java

Log4js is a port of the popular Java framework Log4j. It offers familiar configuration through levels and appenders.

import log4js from 'log4js';

log4js.configure({  appenders: {    out: { type: 'stdout' },    app: { type: 'file', filename: 'application.log' }  },  categories: {    default: { appenders: ['out', 'app'], level: 'debug' }  }});

const logger = log4js.getLogger();logger.debug('Connection debugging');logger.error('Critical error');

Strengths: