Lookalike Audience Builder: Create Meta Lookalikes That Actually Convert
A lookalike audience asks Meta to find new people who resemble a group you already trust — usually your customers. It’s how you turn your best buyers into a prospecting audience instead of guessing at interests. Here’s how to build one the current way, how to choose the source and size, and how Kelpi’s agent can create one for you as part of a campaign.
Building one in Ads Manager.
- 1
Open Audiences in Ads Manager.
In Meta Ads Manager, open the Audiences section (or find it under Business Manager). This is where every custom and lookalike audience for your ad account lives.
- 2
Create a lookalike audience.
Choose Create audience → Lookalike audience. A lookalike asks Meta to find new people who resemble a source group you already trust.
- 3
Pick a strong source.
Point it at your best first-party data — a customer list, purchasers, or a pixel-based audience. The source needs a minimum of about 100 people from a single country, but quality beats size: a clean list of buyers outranks a big list of casual page-followers.
- 4
Set the location and size.
Choose the country you want to reach, then a size from 1% (the closest match to your source) up to 10% (the broadest reach). Start at 1% for the tightest resemblance.
- 5
Create, then let it populate.
Meta builds the audience over roughly 6–24 hours and refreshes it every few days. In 2026 the strongest move is to add this lookalike as an audience suggestion inside an Advantage+ campaign — it gives the AI a strong starting signal while letting it expand beyond the lookalike when it finds better-performing people.
1%, 3–5%, or 10%?
1% — precision
The tightest resemblance to your source. Best when your source is high-quality (purchasers, high-LTV customers) and you want match quality over reach. The right default to start with.
3–5% — scaling
Widen the net once a 1% lookalike has proven it can convert. You trade a little resemblance for more reach, which matters when the 1% audience gets too small or fatigues.
10% — reach
The broadest option, closer to interest-free prospecting. Useful for large markets or as an Advantage+ signal, but expect looser resemblance — pair it with creative that qualifies the click.
One honest caveat: these are sizing principles, not promises. No audience setting locks in a result — the source quality and the creative do most of the work.
The agent can create the lookalike for you.
The toolset Kelpi’s agent operates includes lookalike audience creation (create_lookalike_audience), so when a campaign plan calls for one, the agent can create it as part of the build rather than leaving you to set it up by hand. To be clear about how this works: this is a capability in the agent’s toolkit, not a self-running service — you stay in control of what runs.
- How do I create a lookalike audience on Facebook?
- In Meta Ads Manager, open Audiences, choose Create audience → Lookalike audience, pick a source (a customer list, purchasers, or a pixel-based audience with at least about 100 people from one country), set the target country and a size from 1% to 10%, and create it. Meta builds the audience over roughly 6–24 hours and refreshes it every few days. In 2026 many advertisers then add that lookalike as an audience suggestion inside an Advantage+ campaign rather than running it as a fixed audience.
- What source audience works best for lookalikes?
- Your highest-intent first-party data. A clean list of actual purchasers or high-value customers produces a far better lookalike than a broad list of page-followers or all-site-visitors, because Meta models whatever signal you feed it. Aim for a source that is both reasonably sized (comfortably above the ~100-person minimum) and genuinely representative of the customer you want more of. Quality of the source matters more than its raw size.
- What size lookalike should I use?
- Start at 1%. That is the closest match to your source and usually the best place to begin. Once a 1% lookalike has proven it converts, you can widen to 3–5% to scale reach, accepting slightly looser resemblance. The 10% option is the broadest and behaves more like open prospecting — useful for big markets or as an Advantage+ signal, but pair it with creative that filters for the right click.
- Do lookalike audiences still work?
- Yes, though their role has shifted. With Advantage+ and broader automated targeting, Meta increasingly treats your audiences as signals rather than hard boundaries, so a lookalike now works best as a strong suggestion that points the AI at the right kind of person while letting it expand. Fed a high-quality source and used to seed an Advantage+ campaign, lookalikes remain one of the most reliable ways to turn your best customers into a prospecting audience.
Already running several audiences? Make sure they aren’t competing — check for audience overlap across your ad sets first. Then see how the AI marketing agent puts audiences, creative, and budget into one plan, or start with a free account audit.