NPM version


Rethinking of CPU profile (collected in Node.js or Chromium browsers) analysis.

STATUS: MVP / proof of concept

The project is at an early stage of development. Some things have yet to be added and polished. Feel free to create an issue if you found a bug or have an idea.



Scenario #1 – A viewer for .cpuprofile files

Head to the viewer on GitHub pages, open a .cpuprofile file or drop it on the page.

Viewer welcome page

Scenario #2 – CLI

Install cpupro globally using npm install -g cpupro or use npx cpupro:

  • cpupro – open viewer without embedded data in default browser
  • cpupro - <test.cpuprofile or cat test.cpuprofile | cpupro - – open viewer with test.cpuprofile data embedded
  • cpupro -h – get usage information:


    cpupro [path-to-cpuprofile] [options]


    -f, --filename <filename>    Specify a filename for a report; should ends with .htm or .html,
                                 otherwise .html will be added
    -h, --help                   Output usage information
    -n, --no-open                Prevent open a report in browser, the report will be written to file
    -o, --output-dir <path>      Specify an output path for a report (current working dir by default)
    -v, --version                Output version

Scenario #3 – A library for Node.js program

Main cpupro API is similar to console.profile() / console.stopProfile() with an exception that the profileEnd() method does nothing but return a profile, the result of profilging with methods for saving data to a file and generating a report:

const profiler = require('cpupro');


// ... do something

const profile = record.profileEnd('profileName');

// write data to .cpuprofile file
// or write a report (the viewer with embedded data) to file'report.html');
// or just open the report in a browser;

It is allowed to have several profiles being collected at once. It’s possible to use a reference to profile record API instead of a profile name:

const profiler = require('cpupro');

const profile = profiler.profile();

// ... do something

// end profiling and open a report in a browser

Scenario #4 – A preload module for Node.js scripts

Collect data, generate report and open it in a browser:

node --require cpupro path/to/script.js

Collect data, generate report and write into a file:

node --require cpupro/file path/to/script.js
# or
node --require cpupro/file/report path/to/script.js

Collect data and write it into .cpuprofile file:

node --require cpupro/file/data path/to/script.js




View Github