JavaScript quick start guide

Where do you want to collect your JavaScript logs from?

• Node.js backend only
• Browser only
• Both browser and Node.js backend

Logging from Node.js

Collect logs from the backend code of your application.

1. Install

Install Logtail Node NPM package:

npm install @logtail/node

2. Setup

Set up Logtail client:

const { Logtail } = require("@logtail/node");
const logtail = new Logtail("$SOURCE_TOKEN");

3. Start logging 🎉

logtail.error("Something bad happend.");
logtail.info("Log message with structured data.", {
    item: "Orange Soda",
    price: 100.00
});

// Ensure that all logs are sent to Logtail
logtail.flush()

You should see your logs in Logtail -> Live tail.

Node.js version 12 or higher is required.

Logging from browser

Collect logs from your frontend code.

1. Install

Install Logtail Browser NPM package:

npm install @logtail/browser

2. Setup

Set up Logtail client:

import { Logtail } from "@logtail/browser";
const logtail = new Logtail("$SOURCE_TOKEN");

Prefer using a Content Delivery Network?
Add Logtail import to your HTML page:

<script src="https://cdnjs.cloudflare.com/ajax/libs/logtail-browser/0.3.0/dist/umd/logtail.js" integrity="sha512-j7t6vlvFm1ANrX6dGt+NFtZqOjWeeNlPmAWCkf8mf1n7CMjZVubwUBEvNiVT0RE7voXE7ojiQBNWsAreLg00CA==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>

3. Start logging 🎉

logtail.error("Something bad happend.");
logtail.info("Log message with structured data.", {
    item: "Orange Soda",
    price: 100.00
});

// Ensure that all logs are sent to Logtail
logtail.flush()

You should see your logs in Logtail -> Live tail.

Logging from browser and Node.js

Collect logs from both backend and frontend code of your Node.js application.

1. Install

Install Logtail JavaScript NPM package:

npm install @logtail/js

2. Setup

Set up Logtail client in backend and frontend code:

const { Node: Logtail } = require("@logtail/js");
const logtail = new Logtail("$SOURCE_TOKEN");

import { Browser as Logtail } from "@logtail/js";
const logtail = new Logtail("$SOURCE_TOKEN");

3. Start logging 🎉

Log the same way in backend and frontend:

logtail.error("Something bad happend.");
logtail.info("Log message with structured data.", {
    item: "Orange Soda",
    price: 100.00
});

// Ensure that all logs are sent to Logtail
logtail.flush()

You should see your logs in Logtail -> Live tail.

Node.js version 12 or higher is required.

Need help?

Please let us know at hello@betterstack.com.
We're happy to help! 🙏

Additional information

• Want to learning more about log levels and middleware in Node.js?
  Continue to the Advanced usage of Logtail JavaScript client.

• New to logging? See the Intro guide to Node.js logging and the Best practices for logging in Node.js.

NPM packages

Package @logtail/js provides a convenient way to install and manage both @logtail/node and @logtail/browser NPM packages. You can install the packages separately if you wish to.