Winston Has a Free API — Here's How to Build Production Logging in Node.js

Winston is the most popular logging library for Node.js. It supports multiple transports, log levels, formatting, and structured logging for production applications.

Installation

npm install winston

Basic Setup

import winston from "winston";

const logger = winston.createLogger({
  level: "info",
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.errors({ stack: true }),
    winston.format.json()
  ),
  defaultMeta: { service: "my-api" },
  transports: [
    new winston.transports.File({ filename: "error.log", level: "error" }),
    new winston.transports.File({ filename: "combined.log" })
  ]
});

// Console in development
if (process.env.NODE_ENV !== "production") {
  logger.add(new winston.transports.Console({
    format: winston.format.combine(
      winston.format.colorize(),
      winston.format.simple()
    )
  }));
}

export default logger;

Logging

logger.info("Server started", { port: 3000 });
logger.warn("Slow query detected", { query: "SELECT...", duration: 2500 });
logger.error("Database connection failed", { host: "db.example.com", error: err.message });

try {
  await riskyOperation();
} catch (err) {
  logger.error("Operation failed", { error: err });
}

Custom Formats

const myFormat = winston.format.printf(({ level, message, timestamp, ...meta }) => {
  return `${timestamp} [${level}]: ${message} ${Object.keys(meta).length ? JSON.stringify(meta) : ""}`;
});

const logger = winston.createLogger({
  format: winston.format.combine(
    winston.format.timestamp({ format: "YYYY-MM-DD HH:mm:ss" }),
    myFormat
  )
});

Child Loggers

function handleRequest(req) {
  const requestLogger = logger.child({ requestId: req.id, userId: req.user?.id });
  requestLogger.info("Processing request", { path: req.url });
  requestLogger.info("Request completed", { status: 200, duration: 150 });
}

Multiple Transports

const logger = winston.createLogger({
  transports: [
    new winston.transports.Console(),
    new winston.transports.File({ filename: "app.log", maxsize: 5242880, maxFiles: 5 }),
    new winston.transports.Http({ host: "log-server.example.com", port: 8080 })
  ]
});

---

Need to extract or automate web content at scale? Check out my web scraping tools on Apify — no coding required. Or email me at [e-mail] for custom solutions.