Svelte

Sentry's Svelte SDK enables automatic reporting of errors and exceptions, as well as tracing for your client-side Svelte apps.

We have recently released v8 of the JavaScript SDKs. If you're using version 7.x, we recommend upgrading to the latest version. Check out the Migration docs to learn how to update your code to be compatible with v8.

Don't already have an account and Sentry project established? Head over to sentry.io, then return to this page.

In addition to capturing errors, you can monitor interactions between multiple services or applications by enabling tracing. You can also get to the root of an error or performance issue faster, by watching a video-like reproduction of a user session with session replay.

Select which Sentry features you'd like to install in addition to Error Monitoring to get the corresponding installation and configuration instructions below.

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

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npm install @sentry/svelte --save

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

To use the SDK, initialize it in your Svelte entry point before bootstrapping your app. In a typical Svelte project, that is your main.js or main.ts file.

main.js
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import "./app.css";
import App from "./App.svelte";

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

// Initialize the Sentry SDK here
Sentry.init({
  dsn: "<Sentry DSN>",
  integrations: [
    Sentry.browserTracingIntegration(),
    Sentry.replayIntegration(),
  ],

  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for tracing.
  // We recommend adjusting this value in production
  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 100% of sessions with an error
  replaysSessionSampleRate: 0.1,
  replaysOnErrorSampleRate: 1.0,
});

const app = new App({
  target: document.getElementById("app"),
});

export default app;

Once you've done this, the SDK will automatically capture unhandled errors and promise rejections, and monitor performance in the client. You can also manually capture errors.

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

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

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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.

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

SomeCmponent.svelte
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<button
  type="button"
  on:click={() => {
    throw new Error("Sentry Frontend Error");
  }}
>
  Throw error
</button>;

This snippet adds a button that throws an error in a Svelte component.

Learn more about manually capturing an error or message in our Usage documentation.

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

Help improve this content
Our documentation is open source and available on GitHub. Your contributions are welcome, whether fixing a typo (drat!) or suggesting an update ("yeah, this would be better").