> For the complete documentation index, see [llms.txt](https://help.littledata.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.littledata.io/get-started/how-server-side-tracking-works.md).

# How server-side tracking works

### Browser (client-side) tracking

During the automatic [installation process](https://help.littledata.io/integrations/shopify-to-google-analytics/littledata-shopify-install-guide), Littledata adds a data layer and a tracking script to every page of your store.

* A `LittledataLayer` JavaScript object is added to every page. You can also use it with [Google Tag Manager (GTM)](https://help.littledata.io/integrations/shopify-to-google-analytics/google-tag-manager-faq).
* A small tracking script loads through Littledata's [app embed](https://help.littledata.io/advanced/developer/littledata-app-embed-how-it-works) in your Shopify theme.
* Each marketing platform's own tracking library then loads on the page.
* The script sends cookie identifiers to Littledata's servers, so the shopper's journey stays connected.

### Server-side tracking

During setup, Littledata also adds a set of webhooks to your Shopify store. Each time a shopper takes an action, like updating a cart or placing an order, Shopify notifies Littledata. Littledata's servers then send that event to your marketing platforms.

This approach has several benefits:

* A smaller script in the browser, so pages load faster.
* Complete tracking of the checkout, including orders, post-purchase upsells, refunds and returns.
* No missed or double-counted orders from the order status page.
* More accurate marketing attribution, because sessions are stitched together across checkout types.
* A consistent identity for each shopper over time.
* Less spam, because only Littledata's servers send these events to your destinations.

## Why use server-side tracking

* **Ad blockers and browser limits:** when ad blockers or iOS and Safari restrictions block a platform's own script, Littledata can still send events to that platform's servers.
* **Richer data:** Littledata adds extra product and customer data from Shopify to each event.
* **Custom events:** you can customize events before Littledata sends them.

## Destinations that support server-side tracking

All our major destinations support server-side tracking, including:

* [Google Analytics](/integrations/shopify-to-google-analytics/how-it-works-shopify-to-ga4.md)
* [Google Ads](/integrations/google-ads/google-ads-how-it-works.md)
* [Meta Ads](/integrations/facebook-capi/how-it-works-shopify-to-meta-conversions-api.md)
* [TikTok Ads](/integrations/tiktok/how-it-works.md)
* [Pinterest](/integrations/shopify-to-pinterest/how-it-works.md)
* [Microsoft Ads](https://help.littledata.io/integrations/microsoft-ads)
* [Klaviyo](/integrations/shopify-klaviyo/how-it-works-shopify-to-klaviyo.md)
* [Attentive](/integrations/attentive/how-it-works-shopify-to-attentive.md)
* [Segment](https://help.littledata.io/integrations/shopify-to-segment/how-it-works)

## Supported identifiers

Our advanced tracking script automatically fetches and passes to Littledata servers the following identifiers:

| Identifier              | Description                 |
| ----------------------- | --------------------------- |
| \_ga                    | Google Analytics client ID  |
| \_ga\_\<Measurement ID> | Google Analytics session ID |
| \_gcl\_aw               | Google Ads click identifier |
| \_gcl\_ag               | Google Ads gbraid           |
| \_gcl\_gb               | Google Ads wbraid           |
| \_epik                  | Pinterest click ID          |
| \_ttp                   | Tiktok client ID            |
| ttclid                  | TikTok click ID             |
| fbp                     | Meta client ID              |
| fbc                     | Meta click ID               |
| ajs\_anonymous\_id      | Segment anonymous ID        |

To see which customer details Littledata sends to each destination, see [Shopify data security](https://help.littledata.io/advanced/developer/shopify-data-security).

Need help? Email <help@littledata.io>.

### Related articles

* [Littledata's app embed](https://help.littledata.io/advanced/developer/littledata-app-embed-how-it-works)
* [Known limitations of Littledata's Shopify tracking](https://help.littledata.io/advanced/developer/known-limitations-of-littledatas-shopify-tracking)
* [Shopify data security](https://help.littledata.io/advanced/developer/shopify-data-security)