Svelte

Learn how to manually set up Sentry in your Svelte app and capture your first errors.

Agent-Assisted Setup
Use curl to download, read and follow: https://skills.sentry.dev/sentry-svelte-sdk/SKILL.md
Your agent will set up Sentry in your Svelte app automatically. Works with Cursor, Claude Code, Codex, and more.View docs ↗
Install the full skills package

Run this in your project to add Sentry agent skills. See the installation docs for more details.

Copied
npx @sentry/dotagents add getsentry/sentry-for-ai --name sentry-svelte-sdk

You need:

Run the command for your preferred package manager to add the Sentry SDK to your application:

Copied
npm install @sentry/svelte --save

Choose the features you want to configure, and this guide will show you how:

Want to learn more about these features?
  • Issues (always enabled): Sentry's core error monitoring product that automatically reports errors, uncaught exceptions, and unhandled rejections. If you have something that looks like an exception, Sentry can capture it.
  • Tracing: Track software performance while seeing the impact of errors across multiple systems. For example, distributed tracing allows you to follow a request from the frontend to the backend and back.
  • Session Replay: Get to the root cause of an issue faster by viewing a video-like reproduction of what was happening in the user's browser before, during, and after the problem.
  • Logs: Centralize and analyze your application logs to correlate them with errors and performance issues. Search, filter, and visualize log data to understand what's happening in your applications.
  • User Feedback: Collect feedback directly from users when they encounter errors, allowing them to describe what happened and provide context that helps you understand and resolve issues faster.

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
Copied
import { mount } from "svelte";
import "./app.css";
import App from "./App.svelte";

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

// Initialize the Sentry SDK here
Sentry.init({
  dsn: "___PUBLIC_DSN___",

  // Adds request headers and IP for users, for more info visit:
  // https://docs.sentry.io/platforms/javascript/guides/svelte/configuration/options/#sendDefaultPii
  sendDefaultPii: true,

    // ___PRODUCT_OPTION_START___ performance
    Sentry.browserTracingIntegration(),
    // ___PRODUCT_OPTION_END___ performance
    // ___PRODUCT_OPTION_START___ session-replay
    Sentry.replayIntegration(),
    // ___PRODUCT_OPTION_END___ session-replay
    // ___PRODUCT_OPTION_START___ user-feedback
    Sentry.feedbackIntegration({
      // Additional SDK configuration goes in here, for example:
      colorScheme: "system",
    }),
    // ___PRODUCT_OPTION_END___ user-feedback
  // ___PRODUCT_OPTION_START___ logs

  // Enable logs to be sent to Sentry
  enableLogs: true,
  // ___PRODUCT_OPTION_END___ logs

  // ___PRODUCT_OPTION_START___ performance
  // 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/],
  // ___PRODUCT_OPTION_END___ performance
  // ___PRODUCT_OPTION_START___ session-replay

  // Capture Replay for 10% of all sessions,
  // plus 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,
  // ___PRODUCT_OPTION_END___ session-replay
});

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

export default app;

The stack traces in your Sentry errors probably won't look like your actual code without unminifying them. To fix this, upload your source maps to Sentry. The easiest way to do this is by using the Sentry Wizard.

Alternatively, take a look at our Uploading Source Maps documentation.

Copied
npx @sentry/wizard@latest -i sourcemaps

You can prevent ad blockers from blocking Sentry events using tunneling. Use the tunnel option in Sentry.init to add an API endpoint in your application that forwards Sentry events to Sentry servers.

This will send all events to the tunnel endpoint. However, the events need to be parsed and redirected to Sentry, so you'll need to do additional configuration on the server. You can find a detailed explanation on how to do this on our Troubleshooting page.

Copied
Sentry.init({
  dsn: "___PUBLIC_DSN___",

  tunnel: "/tunnel",

});

Let's test your setup and confirm that Sentry is working correctly and sending data to your Sentry project.

To verify that Sentry captures errors and creates issues in your Sentry project, add the following test button to one of your pages, which will trigger an error that Sentry will capture when you click it.

SomeComponent.svelte
Copied
<button
  type="button"
  onclick={() => {
    throw new Error("Sentry Frontend Error");
  }}
>
  Throw error
</button>;

To test your tracing configuration, update the previous code snippet to start a performance trace to measure the time it takes for the execution of your code.

Then, open the page in a browser and click the button to trigger a frontend error and performance trace.

SomeComponent.svelte
Copied
<button
  type="button"
  onClick={() => {
    Sentry.startSpan({ op: "test", name: "Example Frontend Span" }, () => {
      setTimeout(() => {
        throw new Error("Sentry Frontend Error");
      }, 99);
    });
  }}
>
  Throw error
</button>;

To verify that Sentry catches your logs, add some log statements to your application:

Copied
Sentry.logger.info("User example action completed");

Sentry.logger.warn("Slow operation detected", {
  operation: "data_fetch",
  duration: 3500,
});

Sentry.logger.error("Validation failed", {
  field: "email",
  reason: "Invalid email",
});

Now, head over to your project on Sentry.io to view the collected data (it takes a couple of moments for the data to appear).

Need help locating the captured errors in your Sentry project?
  • Open the Issues page and select an error from the issues list to view the full details and context of this error. For more details, see this interactive walkthrough.
  • Open the Traces page and select a trace to reveal more information about each span, its duration, and any errors. For an interactive UI walkthrough, click here.
  • Open the Replays page and select an entry from the list to get a detailed view where you can replay the interaction and get more information to help you troubleshoot.
  • Open the Logs page and filter by service, environment, or search keywords to view log entries from your application. For an interactive UI walkthrough, click here.
  • Open the User Feedback page and click on individual feedback to see more details all in one view. For more information, click here.

At this point, you should have integrated Sentry into your Svelte application and should already be sending data to your Sentry project.

Now's a good time to customize your setup and look into more advanced topics. Our next recommended steps for you are:

Are you having problems setting up the SDK?
Previous
Welcome to Sentry
Next
Capturing Errors
Was this helpful?
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").