Svelte Surveys installation

Install the package

Required

Install the PostHog JavaScript library using your package manager:

npm install posthog-js
yarn add posthog-js
pnpm add posthog-js

Initialize PostHog

Required

If you haven't created a root layout already, create a new file called +layout.js in your src/routes folder. Check the environment is the browser, and initialize PostHog if so:

src/routes/+layout.js
import posthog from 'posthog-js'
import { browser } from '$app/environment';
import { onMount } from 'svelte';

export const load = async () => {
  if (browser) {
    posthog.init(
      '<ph_project_token>',
      {
        api_host: 'https://us.i.posthog.com',
        defaults: '2026-01-30'
      }
    )
  }

  return
};

SvelteKit layout

Learn more about SvelteKit layouts in the official documentation.

Server-side setup

Optional

Install posthog-node using your package manager:

npm install posthog-node --save
yarn add posthog-node
pnpm add posthog-node
bun add posthog-node

Then, initialize the PostHog Node client where you'd like to use it on the server side. For example, in a load function:

routes/+page.server.js
import { PostHog } from 'posthog-node';

export async function load() {
  const posthog = new PostHog('<ph_project_token>', { host: 'https://us.i.posthog.com' });

  posthog.capture({
    distinctId: 'distinct_id_of_the_user',
    event: 'event_name',
  })

  await posthog.shutdown()
}

Note

Make sure to always call posthog.shutdown() after capturing events from the server-side. PostHog queues events into larger batches, and this call forces all batched events to be flushed immediately.

Send events

Click around and view a couple pages to generate some events. PostHog automatically captures pageviews, clicks, and other interactions for you.

If you'd like, you can also manually capture custom events:

JavaScript
posthog.capture('my_custom_event', { property: 'value' })

Next steps

Recommended

After installing the PostHog SDK, you can create your first survey.

Resource	Description
Creating surveys	Learn how to build and customize your surveys
Targeting surveys	Show surveys to specific users based on properties, events, or feature flags
How to create custom surveys	Build advanced survey experiences with custom code
Framework guides	Setup guides for React, Next.js, Vue, and other frameworks
More tutorials	Other real-world examples and use cases

You should also identify users and capture events with PostHog to control who and when to show surveys to your users.

Not all survey features are available on every SDK. See the SDK feature support matrix for a full comparison.