Profiling Node.js apps with Chrome DevTools profiler

Published July 5, 2024・Last updated July 5, 2024・1 min read

Profiling refers to analyzing and measuring an application's performance characteristics.

Profiling helps identify performance bottlenecks in a Node.js app, such as CPU-intensive tasks like cryptographic operations, image processing, or complex calculations.

This post covers running a profiler for various Node.js apps in Chrome DevTools.

Prerequisites

Google Chrome installed
Node.js app bootstrapped

Setup

Run node --inspect app.js to start the debugger.
Open chrome://inspect, click Open dedicated DevTools for Node and then navigate to the Performance tab. Start recording.
Run load testing via autocannon package using the following command format npx autocannon <COMMAND>.
Stop recording in Chrome DevTools.

Profiling

On Perfomance tab in Chrome DevTools open Bottom-Up subtab to identify which functions consume the most time.

Look for potential performance bottlenecks, such as synchronous functions for hashing (pbkdf2Sync) or file system operations (readFileSync).