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

# Lookalike audiences

> Ask Meta to find new people who resemble one of your synced audiences, and use the result to target prospecting campaigns.

A lookalike audience is built by Meta from a **seed**: one of your Meta Custom Audiences. Meta looks for people in a chosen country who resemble the seed. Use a lookalike to reach new prospects who look like your best customers.

<Note>
  Lookalikes are available for **Meta Ads** only. Google Ads doesn't offer lookalike audiences to third-party tools. Only **Owners** and **Admins** can create them.
</Note>

## Before you start

* Meta Ads is connected and the ad account has accepted Meta's Custom Audience Terms.
* You have a Meta audience that is **linked to a segment** or filled by a journey. See [Sync audiences](/guides/ads/audiences).
* The seed has **at least 100 people Meta has matched**. Meta refuses smaller seeds, and its message is shown when you try to create the lookalike.

## Create a lookalike

<Steps>
  <Step title="Find the seed audience">
    Go to **Advertising → Audiences** and find the Meta audience to use as the seed.
  </Step>

  <Step title="Open the lookalike dialog">
    Click the sparkle icon (**Create lookalike**) on that row. It appears only on Meta audiences that aren't lookalikes themselves.
  </Step>

  <Step title="Fill in the details">
    * **Audience name**: the name shown in your Meta ad account.
    * **Country**: the population the lookalike is drawn from.
    * **Size**: 1% to 20% of that country's population. 1% is the closest match, and larger sizes reach more people who resemble the seed less.
    * **Optimise for**: **Similarity** or **Reach**.
  </Step>

  <Step title="Create it">
    Click **Create lookalike**. You'll see "Lookalike created — Meta is populating it".
  </Step>
</Steps>

## Watch it populate

Meta takes about **1 to 6 hours** to build a lookalike. In the audience table, a lookalike carries a **Lookalike** badge, the line "Seeded from …", and its size, country and type. Its status reads:

| Status          | Meaning                                              |
| --------------- | ---------------------------------------------------- |
| **NOT CHECKED** | Nobody has asked Meta about it yet.                  |
| **POPULATING**  | Meta is still building it.                           |
| **READY**       | Meta has finished and the lookalike can be targeted. |

Click **Check with the platform** (the magnifier icon) to refresh the status and approximate size.

## What you can and can't do with a lookalike

* **Nothing is uploaded to it.** Meta decides who is in a lookalike, so it has no **Sync now** or **Auto-sync**. The tooltip reads "Lookalikes are modelled by the platform — there is nothing to sync".
* **Use it in a campaign.** Lookalikes appear under **Include audiences** and **Exclude audiences** on the **Audience** step of a Meta campaign, marked **Lookalike**. See [Create an ad campaign](/guides/ads/create-campaign).
* **The seed can be deleted.** If you delete the seed audience's mapping, the lookalike stays, and Meta keeps modelling it from what it already has. Its row then reads "Seeded from a deleted audience".
* **Deleting the lookalike's mapping** removes it from InstantCampaign only. The audience stays in your Meta ad account.

## Troubleshooting

| What you see                                                      | What to do                                                                                                     |
| ----------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| Creating fails with a Meta message about the source audience size | The seed has fewer than 100 matched people. Grow the segment, sync it, wait for Meta to match, then try again. |
| No sparkle icon on an audience                                    | The audience is on Google Ads, is itself a lookalike, or you aren't an Owner or Admin.                         |
| The status stays **POPULATING** for more than 6 hours             | Click **Check with the platform**. If it still isn't ready, check the audience in Meta Ads Manager.            |