# meta-externalads

> meta-externalads is Meta's ad-landing-page crawler. When an advertiser submits a destination URL for an ad placed on Facebook, Instagram, Messenger, or Audience Network, this bot fetches the landing page to assess policy compliance, brand safety, and to render preview thumbnails.

Source: https://docs.centinelanalytica.com/crawlers/meta-externalads

## At a glance

- Operator: [Meta](https://developers.facebook.com/docs/sharing/webmasters/crawler/)
- Type: Advertising

## How Centinel checks it

- **User agent**: The request calls itself this crawler. Anyone can send the same string.
- **IP ranges**: The operator publishes the addresses it crawls from, and Centinel checks the client address against that list.

A request that passes one of these checks is meta-externalads itself. One that only matches the user agent is reported as unverified. The match tokens, verification domains, and address feeds are not published here.

## Allowing or blocking it

The [crawler object](https://docs.centinelanalytica.com/api/crawlers.md) in the `/validate` response sets `access_allowed` to `true` only for a verified source that your tenant allowlists. A [policy rule](https://docs.centinelanalytica.com/admin/policy.md) can allow or block this crawler by its category, `Advertising`.

[Back to the crawler catalog](https://docs.centinelanalytica.com/concepts/crawler-catalog.md)

[Crawlers with a source check](https://docs.centinelanalytica.com/crawlers.md)