> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upstackdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Server Dedupe Coverage: Conversions API Deduplication

> Track what percentage of your server-side Conversions API events include a deduplication key. Higher coverage ensures accurate deduplication against browser pixel events.

<Tip>
  Server Dedupe Coverage measures the percentage of server-side Conversions API events that include a deduplication key, enabling accurate deduplication against browser pixel events.
</Tip>

## Formula

<Info>
  **Server Dedupe Coverage** = **Server Events with Dedupe Key** ÷ **Total Server Events** × 100
</Info>

### Formula Components

| Metric                            | Definition                                                         |
| --------------------------------- | ------------------------------------------------------------------ |
| **Server Events with Dedupe Key** | Conversions API events that include an event\_id for deduplication |
| **Total Server Events**           | All server-side Conversions API events sent to Meta                |

| Metadata        |                                   |
| --------------- | --------------------------------- |
| **Type**        | Percentage                        |
| **Data Source** | [Meta Ads](/sources/facebook-ads) |
| **Aggregation** | Average                           |

***

## Example

A brand's Conversions API sends **8,920 server events** in January. **8,654** include a deduplication key.

| Metric                        | Value     |
| ----------------------------- | --------- |
| Server Events with Dedupe Key | 8,654     |
| Total Server Events           | 8,920     |
| **Server Dedupe Coverage**    | **97.0%** |

***

## How It Works

When you send events via the Conversions API, Meta needs a deduplication key (event\_id) to match them against browser pixel events and avoid double-counting. Server Dedupe Coverage shows how many of your server events include this key. Higher coverage means Meta can accurately deduplicate overlapping browser and server events, improving attribution accuracy.

***

## When to Use

| Scenario                        | Action                                                                     |
| ------------------------------- | -------------------------------------------------------------------------- |
| Coverage below 95%              | Verify your Conversions API implementation sends event\_id with all events |
| Conversion counts seem inflated | Check both server and browser dedupe coverage for mismatches               |
| Implementing Conversions API    | Ensure event\_ids match between browser pixel and server events            |
| Optimizing EMQ Score            | Improve server dedupe coverage to enable accurate deduplication            |

***

## Related Metrics

| Metric                                                                                   | Relationship                                                           |
| ---------------------------------------------------------------------------------------- | ---------------------------------------------------------------------- |
| [Browser Dedupe Coverage](/reference/metrics/data-quality/emq/browser-dedupe-coverage)   | Browser-side equivalent—both should be high for accurate deduplication |
| [Overall Browser Coverage](/reference/metrics/data-quality/emq/overall-browser-coverage) | Combined deduplication effectiveness across all browser events         |

[See all EMQ metrics →](/reference/metrics/data-quality/emq)