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A Node.js application profiling tool.

Project Info
License: Apache-2.0
Build: make
Issue tracker:
Engines: Node.js 4.x, 6.x, 7.x

This is a simple Node.js profiling tool. Use it like this. First add it to your project.


$ npm install genet -S


Then start profiling. Put this somewhere in your app. Probably near the start.

const Genet = require('genet');
const profile = new Genet();


When requiring the genet module, the module exports the Genet object's constructor function.

// Genet is a constructor function 
const Genet = require('genet');
var profile = new Genet();

new Genet(options)

Creates a new profiler. Several options are allowed.

  • options.profileName {string} - The profile name provided to v8-profiler. Defaults to 'genet'.
  • options.outputFile {string} - The output file name. Defaults to ./prof-${}.cpuprofile.
  • options.duration {Number} - The number of milliseconds to run the profiler. Defaults to 5000.
  • options.verbose {boolean} - Determines how much log output you'll see. Defaults to false.
  • {boolean} - Whether or not to generate report output. Defaults to true.
  • options.flamegraph {boolean} - Determines whether to generate a flamegraph .svg file. Defaults to false.
  • options.filter {RegExp|String} - An inclusive filter which determines what functions to include in the reports based on comparison with the path and filename for a given function.


Begins profiling the application. The profiler will run until options.duration milliseconds have elapsed, and then generate reports.


Stops profiling the application. If the profiler has already been stopped, this function does nothing. If the profiler is still running, it cancels the timeout set by options.duration and then stops the profiler. This function returns a promise that resolves when the profiler has stopped.


By default, genet will generate a report to the console, and to a file. Using the flamegraph option, you can also generate a flamegraph as an .svg file.

Console output will look something like this.

alt example

The flamegraph SVG might look something like this.

alt flamegraph


Please read the contributing guide