Add Observability to Lightning Web Components with lightning/logger

Learn how to use the lightning/logger instrumentation API to add observability to your custom Lightning Web Components. Includes setup steps, a minimal example, and best practices.

What is lightning/logger?

lightning/logger is a lightweight instrumentation API provided by Salesforce that lets developers log structured events from Lightning Web Components (LWC) to the Lightning Logger Event Type in Event Monitoring. It helps teams capture user interactions and component behavior without noisy console logs, and integrates with Salesforce Event Monitoring for centralized observability.

Prerequisites

Before using lightning/logger you must:

• Use Lightning Experience (lightning/logger is not available in Salesforce mobile app).
• Enable Event Monitoring in your org.
• From Setup, open Event Monitoring Settings and toggle Enable Lightning Logger Events to On.

Quick example

Import the API and log structured messages from your LWC. The API accepts strings or objects and automatically stringifies objects.

// instrumentationAPI.js
import { LightningElement } from 'lwc';
import { log } from 'lightning/logger';

export default class InstrumentationAPI extends LightningElement {
    handleClick() {
        let msg = {
            type: 'Click',
            action: 'Approve'
        };
        log(msg);
        console.log(JSON.stringify(msg));
    }
}

Usage notes and best practices

• Keep messages concise — the maximum string length is 4096 characters.
• Prefer structured objects over freeform strings so downstream analytics can parse fields.
• Use meaningful event types and actions (e.g., {type: ‘Form’, action: ‘Submit’}).
• Don’t log sensitive data (PII) to Lightning Logger events.
• Instrument critical UI flows: form submissions, approval clicks, navigation events.

Where this helps

Using lightning/logger helps admins and developers debug issues in production-like environments, create audit trails for user interactions, and feed observability pipelines (SIEM, analytics). It’s particularly useful for complex LWCs where behavior depends on asynchronous data and user actions.

Actionable steps

• Enable Event Monitoring Settings > Enable Lightning Logger Events.
• Add log() calls to key LWC event handlers.
• Verify events appear in Event Monitoring (and configure retention/forwarding as needed).

Conclusion

Instrumenting your Lightning Web Components with lightning/logger is a low-effort, high-value way to add observability. It provides structured event logging that plays nicely with Salesforce Event Monitoring and downstream analytics tools — helping teams find and fix issues faster.

Why this matters: Salesforce admins and developers gain clearer insights into user behavior and component failures without polluting the browser console or relying solely on manual debugging. Business users benefit from faster resolutions and more reliable apps.