Implementing upixel and RT conversion events together
The Trade Desk provides two complementary real-time conversion tracking mechanisms: universal pixel (upixel) and Real-Time Conversion Events API (RT CAPI). This page explains how they relate to each other and how to implement them together using different methods.
Upixel vs. real-time conversion events
The two mechanisms are complementary. You can run both at the same time: the upixel establishes a persistent visitor pool, and real-time conversion events add granular action-level signals on top of that.
The following table outlines the differences.
| Aspect | Universal pixel | Real-time conversion events |
|---|---|---|
| What it does | Tracks all page visits; powers URL-based site-visit attribution and segments | Tracks specific user actions (purchase, add to cart, sign-up, and so on). Powers event-based attribution and segments. |
| When it fires | On every page load | Only on designated conversion actions (potentially multiple actions per page) |
| Primary use | URL-based attribution and audience building | Conversion event-based attribution, product-level data for attribution and audience building |
| Identifier required | Upixel ID | Event tracker ID |
Implementation quickstarts
Use the following table to identify the right implementation for your environment and the corresponding quickstart guide.
| Environment | Google Tag Manager | No GTM |
|---|---|---|
| Client-side (web) | GTM (client-side) | JS SDK |
| Client-side (in-app) | N/A | RT CAPI |
| Server-side | GTM (server-side) | RT CAPI |
Each quickstart explains how to pass your upixel ID and event tracker ID together in a single call, so you don't need a separate upixel implementation.
Full user guides
For field-level reference and advanced configuration beyond what the quickstarts cover, see the following guides:
Shopify
/doc/DataShopifySummaryOpenTTD
Track site and checkout events directly from your Shopify store, with or without GTM.
Real-Time Conversion Events API
/doc/DataConversionEventsApi
Complete API reference, including all supported ID types, event mapping, URL mapping, and FAQs.
Item-level event tracking tag
/doc/TrackingTagsEvents
Complete reference for the JS tag implementation, including GTM, predefined events, custom metadata, and verification.
FAQs
Do I need a separate upixel implementation if I'm already using the RT CAPI?
No. If you pass your upixel ID alongside your event tracker ID in the pixelIds or pixel_ids array (or the GTM pixel IDs field), the upixel receives the signal without a separate implementation.
What ID do I need to use with a upixel?
Use your advertiser ID for combined upixel and RT CAPI implementations. If you are a commerce advertiser with only a merchant ID and need to use the upixel, contact your Technical Account Manager to confirm the correct setup.
Can I send multiple different conversion event types in the same integration?
Yes. Fire an event at each conversion point on your site (for example, addtocart when a user adds to the cart, purchase on the confirmation page). You can map one page view and one user-interaction event to the same user per call, but not two of the same type.
What happens if I pass only the upixel ID and no event tracker ID?
Events are captured for audience and URL-based attribution tied to the upixel, but you will not have conversion event measurement for specific user actions.