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 Better Stack → Live tail.

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/0.4.19/dist/umd/logtail.min.js" integrity="sha512-EYdnWL7Lrn+96R4BDaOxCgCWWOoZQiMSsfy+3NKYSJxK/CAt6y7cPLvGHRWONYO8Y0SsGuk5Y+lC1w3up7f7OA==" 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 Better Stack → 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 Better Stack → Live tail.

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 Better Stack JavaScript client.

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

• Logging from browser? Some browsers (e.g. Brave, or some browser extensions) may block your logs from being sent. If you need to work around this issue, see possible workarounds on Github.

• Using Bun runtime? No worries, our logging packages are tested in Bun as well as Node.

• Using helper function for logging in Node.js? You can fix the logged context.runtime info by passing stackContextHint to the logger. See the usage in example project to learn more.

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.