Adding timestamps to all console messages

The module log-timestamp works for me.

npm install log-timestamp 

It's simple to use:

console.log('Before log-timestamp'); require('log-timestamp'); console.log('After log-timestamp'); 

Before log-timestamp [2012-08-23T20:08:32.000Z] After log-timestamp 

Create a file with the following:

var log = console.log; console.log = function(){ log.apply(console, [Date.now()].concat(arguments)); }; 

Require it in your app before you log anything. Do the same for console.error if needed.

Note that this solution will destroy variable insertion (console.log("he%s", "y") // "hey") if you're using that. If you need that, just log the timestamp first:

log.call(console, Date.now()); log.apply(console, arguments); 

If you want a solution without another external dependency but you want to keep the full functionalities of console.log (multiple parameters, variable insertion) you can use the following code:

var log = console.log; console.log = function () { var first_parameter = arguments[0]; var other_parameters = Array.prototype.slice.call(arguments, 1); function formatConsoleDate (date) { var hour = date.getHours(); var minutes = date.getMinutes(); var seconds = date.getSeconds(); var milliseconds = date.getMilliseconds(); return '[' + ((hour < 10) ? '0' + hour: hour) + ':' + ((minutes < 10) ? '0' + minutes: minutes) + ':' + ((seconds < 10) ? '0' + seconds: seconds) + '.' + ('00' + milliseconds).slice(-3) + '] '; } log.apply(console, [formatConsoleDate(new Date()) + first_parameter].concat(other_parameters)); }; 

You can modify the formatConsoleDate function to format the date how you want.

This code needs to be written only once on top of your main JavaScript file.

console.log("he%s", "y") will print something like this:

[12:22:55.053] hey 

You could also use the log-timestamp package. It's quite straightforward, and customizable as well.

This implementation is simple, supports original functionality of console.log (passing a single object, and variable substitution), doesn't use external modules and prints everything in a single call to console.log:

var origlog = console.log; console.log = function( obj, ...placeholders ){ if ( typeof obj === 'string' ) placeholders.unshift( Date.now() + " " + obj ); else { // This handles console.log( object ) placeholders.unshift( obj ); placeholders.unshift( Date.now() + " %j" ); } origlog.apply( this, placeholders ); }; 

If you wish, you may create a custom logger for your application by extending the Node's build in "Console" class. Kindly refer to the following implementation

"use strict"; const moment = require('moment'); const util = require('util'); const Console = require('console').Console; class Logger extends Console { constructor(stdout, stderr, ...otherArgs) { super(stdout, stderr, ...otherArgs); } log(...args) { super.log(moment().format('D MMM HH:mm:ss'), '-', util.format(...args)); } error(...args) { super.error(moment().format('D MMM HH:mm:ss'), '-', util.format(...args)); } } module.exports = (function() { return new Logger(process.stdout, process.stderr); }());

After that, you may use it in your code as :

const logger = require('./logger'); logger.log('hello world', 123456); logger.error('some error occurred', err);

A more rudimentary approach, to avoid installing external modules, could be implementing a simple function such as:

function timeStamp(message){ console.log ( '[' + new Date().toISOString().substring(11,23) + '] -', message ) } 

and then I simply call it in this way:

timeStamp('this is my logline!!'); 

the result will be:

 LOG [15:22:30.682] - this is my logline!! 

of course you can format the date in the best format you need and expand the function to console.error, debug, etc.

An answer suitable for 2022

const log = console.log; console.log = function(){ log.apply(console, [new Date(), ...arguments]); }; 

This isn't a direct answer, but have you looked into winston.js? It has a ton more logging options including logging to a json file or database. These always have timestamps by default. Just a thought.

app.use(morgan('[:date[web]] :method :url :status :res[content-length] - :remote-addr - :response-time ms')) 

You can use a function util.log from https://nodejs.org/api/util.html.

Be aware that it was deprecated since version 6.0.0.

For higher versions you should "Use a third party module instead."

I'm trying overwriting the console object - seems to be working well. To use, save the code below in a file, and then import to overwrite the proxy object, and then use as normal.

(Note this requires babel transpilation and won't work in environments that don't support the JavaScript Proxy constructor such as IE 11).

import console from './console-shadow.js' console.log(...) console.warn(...) console.error(...) 

// console-shadow.js // Only these functions are shadowed by default const overwrites = ['log', 'warn', 'info', 'error'] export default new Proxy( // Proxy (overwrite console methods here) {}, // Handler { get: (obj, prop) => prop in obj ? obj[prop] : overwrites.includes(prop) ? (...args) => console[prop].call(console, new Date(), ...args) : console[prop], } ) 

Basically I overwrite the console object with a JavaScript proxy object. When you call .log, .warn, etc. the overwritten console will check if what you are calling is a function, if so it will inject a date into the log statement as the first parameter, followed by all your parameters.

I think the console object actually does a lot, and I don't fully understand it. So I only intercept console.log, console.info, console.warn, console.error calls.

I really like @AndreasHultgren's solution but it did not accept arguments so I expanded on it.

let warnLog = console.warn; console.warn = (...strings) => { let firstFormat = strings.shift(); let dateFormat = '[' + date.format(new Date(), 'YYYY-MM-DD HH:mm:ss') + '] WARN: ' + firstFormat; strings.unshift(dateFormat); warnLog(...strings); }; let errorLog = console.error; console.error = (...strings) => { let firstFormat = strings.shift(); let dateFormat = '[' + date.format(new Date(), 'YYYY-MM-DD HH:mm:ss') + '] ERROR: ' + firstFormat; strings.unshift(dateFormat); errorLog(...strings); }; 

Far off in another part of my NodeJS project.

console.error('settings being read by %s and %s', 'steve', 'tom'); console.warn('Your %s wears %s', 'mother', 'army boots'); 

Many have answered before - no need for packages, you can prepend all console output with the date (and loglevel info) by wrapping the global object (and even retain access to the "native" methods while doing so).

The goal here is to (temporarily?) also catch all pre-existing logging (even from modules) without changing call-signatures (and at the same time e.g. get rid of multiline stacktraces).

['debug','log','info','warn','error'].forEach((method, level)=>{ const type = method.toUpperCase(), native = console[method]; console[method] = Object.assign( function(...args){ native((new Date).toISOString(), type+':', args.join(' ').replace(/(\r\n|\r|\n)/g, '\t')); }, { native } ); }); 

• existing logging will now be timestamped and normalized
• logging that should not have timestamps can call console.log.native(...)

You can allways use log4j, as its written in doku to use third party tools.

I can recommend using the log4j. It does gives more than time but this is a good entry for the future impovements as well.

Please find below example implementation

var log4js = require('log4js'); var logger = log4js.getLogger(); logger.level = 'info'; logger.log('your log message'); 

Example output

[2023-05-01T15:24:12.948] [INFO] default - your log message

Use event listener like this,

process.on('error', function() { console.log('Error Occurred.'); var d = Date(Date.now()).toString(); console.log.call(console, d); // Wed Aug 07 2019 23:40:07 GMT+0100 (GMT+01:00) }); 

happy coding :)