# Understanding data absence

96% of US IOS users opt-out of tracking...

And millions use cookie blockers, ad blockers\
\
When they do, the Pixel is literally helpless

{% hint style="info" %}
**Pixel limitation:** Pixel is a bit vulnerable because it’s easily shut down entirely by anything in the browsers that **don’t allow third-party Javascript to load.**
{% endhint %}

Then, Conversion API came in to save the day

{% hint style="info" %}
**CAPI to the rescue:** CAPI will be fully active no matter the weather, sending data from a server to Facebook’s server. So it’s strong, cool, calm, and collected.
{% endhint %}

But there is always a **trade-off.** CAPI is very tech-demanding, while there are tons of one-click Pixel installations for you to choose from.

If you’re a bit technical then here goes the bonus flow:

<figure><img src="/files/D48p0tAnh29DUp9lOvtt" alt=""><figcaption></figcaption></figure>

**TL;DR?** CAPI ensures no data loss, *Facebook is happy because it gets the full picture of what’s happening.* Think of it as the big brother protecting its little brother - Pixel.

{% hint style="info" %}
📝How to know if a Conversion API tool is good or bad? Check out this blog [Facebook Conversion API simplest explanation & how to look for good server-side solution](https://www.omegatheme.com/blog/456-facebook-conversion-api-simplest-explanation-how-to-look-for-good-server-side-solution)&#x20;
{% endhint %}

{% content-ref url="/pages/clQHbFtcKvLML67Ar62F" %}
[Level up your data with CAPI](/getting-started/level-up-your-data-with-capi.md)
{% endcontent-ref %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.twoowls.io/hot-topics/facebook-attribution/understanding-data-absence.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.