You can use a web pixel app extension to collect behavioral data for marketing campaign optimization and analytics. This guide provides the reference documentation for the web pixel app extension.

## Reference documentation

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  <a class="resource-card" href="/docs/api/web-pixels-api" data-theme-mode="">
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    <h3 class="resource-card__title">
      Web pixel extension API
    </h3>
    <p class="resource-card__description">Learn about the sandboxing modes for web pixels, and the API references that are available for the sandbox.</p>
  </a>
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  <a class="resource-card" href="/docs/api/web-pixels-api/standard-events" data-theme-mode="">
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    <h3 class="resource-card__title">
      Standard Events Reference
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    <p class="resource-card__description">Learn about the ways of tracking and sending events with web pixels.</p>
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## Next steps

- Learn how you can [use web pixels](/docs/apps/build/marketing-analytics/pixels) on an online store to collect behavioral data for marketing campaign optimization and analytics.
- [Create a web pixel app extension](/docs/apps/build/marketing-analytics/build-web-pixels) and subscribe to all events emitted by Shopify.