Rainbowed console logs for chrome in development

npm install bows
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Colors Safe, production happy, colourful logging for chrome - makes reading your logs much easier.

(Rain)bows makes logging debug messages in your apps much nicer.

  • It allows you to create custom loggers for each module in your app, that prefix all log messages with the name of the app, so that you can scan the messages more easily.
  • It colors the prefix differently and distinctly for each logger/module so that it's even easier to read.
  • It can be safely used in production, where logging will be disabled by default, so that you can leave log messages in your code.
  • Loggers safely wrap console.log, to maintain the line number from where they are called in the console output.

Example Output


If you are using browserify, you'll want something like:

npm install bows --save

If you aren't using browserify, download either bows.js or bows.min.js.


  • Easily create prefixes for your logs, so that you can distinguish between logs from different parts of your app easily.
  • In chrome prefixes will be color coded for even easier identification.
  • Can be safely used in production, as logs will be disabled for your users, but can be enabled by you with a local storage flag.
  • Greppable logs by setting localStorage.debug = /Foo/ to only display logs for modules matching the regex to help you focus in development.


  • Works great in browserify and the browser.
  • Creating a new logger:
    • Browserify: var log = require('bows')("My Module Name")
    • Browser: var log = bows("My Module Name")
  • Then using it is easy:
    • log("Module loaded") //-> "My Module Name | Module Loaded"
    • log("Did something") //-> "My Module Name | Did something"
  • Typically each seperate module/view/etc in your app would create it's own logger. It will be assigned it's own color to make it easy to spot logs from different modules.
  • Logging is disabled by default. To enable logging, set localStorage.debug = true in your console and refresh the page.
  • You can leave the code in in production, and log() will just safely no-op unless localStorage.debug is set.


  //Should be set in your console to see messages
  localStorage.debug = true
  //Configure the max length of module names (optional)
  bows.config({ padLength: 10 })

  var logger1 = bows('Module 1')
  var logger2 = bows('Module 2')
  var logger3 = bows('Module 3')

  logger1("We started up")
  logger2("We did something too")
  logger3("I'm here")
  logger3("I'm still here")
  logger2("I'm tired")
  logger1("We're done here")


Example Output

License & Credits


Copyright @Philip_Roberts

Bows depends on andlog, a nice little logging module by @HenrikJoreteg.


Please feel free to raise issues, or make contributions:

git clone
cd bows
npm install #install dependencies
#edit bows.js
node build.js #build dist/bows.js and dist/bows.min.js
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