> For the complete documentation index, see [llms.txt](https://docs.twoowls.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.twoowls.io/hot-topics/facebook-attribution/understanding-data-absence.md).

# 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 %}


---

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