JavaScript

Prerequisites

• You need a Sentry account and project

Install

Sentry captures data by using an SDK within your application’s runtime.

In order to get started using the Sentry JavaScript SDK, add the following code to the top of your application, before all other scripts:

<script
  src="https://js.sentry-cdn.com/examplePublicKey.min.js"
  crossorigin="anonymous"
></script>

The Loader Script allows you to configure some SDK features from the Sentry UI, without having to redeploy your application. The Loader Script documentation shows more information about how to use it.

Alternatively, you can also install the SDK via a package manager:

npm install @sentry/browser --save

If you're updating your Sentry SDK to the latest version, check out our migration guide to learn more about breaking changes.

If you are using our previous Browser Javascript SDK, you can access the legacy SDK documentation, until further notice.

Configure

Configuration should happen as early as possible in your application's lifecycle.

Once this is done, Sentry's JavaScript SDK will capture all unhandled exceptions, transactions, and Session Replays, based on the sample rates set.

Note, that configuration differs slightly depending on how you installed the Sentry SDK. Make sure to follow the instructions in the correct tab, depending on if you installed the Sentry SDK via NPM, using the Loader Script, or via CDN.

import * as Sentry from "@sentry/browser";

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",

  // Alternatively, use `process.env.npm_package_version` for a dynamic release version
  // if your build tool supports it.
  release: "my-project-name@2.3.12",
  integrations: [
    Sentry.browserTracingIntegration(),
    Sentry.replayIntegration(),
  ],

  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for tracing.
  // We recommend adjusting this value in production
  // Learn more at
  // https://docs.sentry.io/platforms/javascript/configuration/options/#traces-sample-rate
  tracesSampleRate: 1.0,

  // Set `tracePropagationTargets` to control for which URLs trace propagation should be enabled
  tracePropagationTargets: ["localhost", /^https:\/\/yourserver\.io\/api/],

  // Capture Replay for 10% of all sessions,
  // plus for 100% of sessions with an error
  // Learn more at
  // https://docs.sentry.io/platforms/javascript/session-replay/configuration/#general-integration-configuration
  replaysSessionSampleRate: 0.1,
  replaysOnErrorSampleRate: 1.0,
});

Add Readable Stack Traces to Errors

Depending on how you've set up your project, the stack traces in your Sentry errors probably won't look like your actual code.

To fix this, upload your source maps to Sentry. The easiest way to do this is by using the Sentry Wizard:

npx @sentry/wizard@latest -i sourcemaps

The wizard will guide you through the following steps:

• Logging into Sentry and selecting a project
• Installing the necessary Sentry packages
• Configuring your build tool to generate and upload source maps
• Configuring your CI to upload source maps

For more information on source maps or for more options to upload them, head over to our Source Maps documentation.

Verify

This snippet includes an intentional error, so you can test that everything is working as soon as you set it up.

setTimeout(() => {
  throw new Error("Sentry Test Error");
});

To view and resolve the recorded error, log into sentry.io and select your project. Clicking on the error's title will open a page where you can see detailed information and mark it as resolved.