logging logo full

Easier Logging for Firebase

Firebase Logging is a free open source tool that we built for the Firebase community. We are regular users of Firebase and this solves a real "logging" need for us. We hope it helps you too.

Check it out on GitHub or npm.

photo_2020-05-04 15.36.36

Why Firebase Logging

Firebase's CLI (command line interface) logging requires you to re-run the tool just to see new data. That becomes a lot of up 'arrow key' and 'enter' pressing.

Firebase Logging gives you (mostly) real-time logging by continually running the Firebase CLI logging command and printing to the console new entires. You can output the logs to the console and a file.

Log enhancements include:

  • Colored Logs: timestamp blue, function name green, warning yellow, and error red. Default.
  • Locally Formatted Timestamp: format from UTC timestamp to your local time. Use --ft parameter to format.


Things to Note
The default polling occurs every 2 seconds. You can set the frequency of polling with the -freq parameter from a minimum of 1500 milliseconds, which is the most Firebase will allow, to an infinite maximum. You might want to increase the frequency if you find the polling is taking too much system resources.

The default pull is 250 lines, so if you have more than 250 lines logs per the polling frequency, some logs will be missed. Increase the number of log lines pulled with the --n parameter to capture more logs (1-1000).

Installing Firebase Logging

npm i -g firebase-logging


  • firebase-tools globally installed.
  • A Firebase project id you want to see the logs of.


firebase-logging --project=[Firebase projectId]


Start the logging to the console for project myFirerun, only for the sendReport function, save to the savelog.txt file, and format the time to local.

firebase-logging --project=myFirerun --func=sendReport --file=savelog.txt --ft



--project [projectId] of Firebase project


--h Help info
--file [File Name] to write the logs
--colorOff Turn off coloring of logs
--func [Function Name] of specific function to view logs
--n [Number] of log lines to pull (1-1000)
-ft Format timestamp to local date and time
--freq [Milliseconds] to poll for new logs

Run using the GitHub code

node firebase-logging.js --project=[Firebase projectId]