Similar Segments
By the AdFlint research team · Last reviewed July 2026
Google's retired audience expansion feature, which generated lookalike-style segments from a seed list before being removed in 2023 in favor of automated targeting.
Similar segments once derived a resembling audience automatically from a remarketing or Customer Match seed, and Google sunset them so campaign-level automation could do that expansion instead. Your seed lists remain valuable as signals feeding optimized targeting and Smart Bidding rather than as sources for a derived list. Advertisers still hunting for the setting almost always want optimized targeting or Customer Match.
Key takeaways
- Similar segments were retired by Google in 2023 and cannot be recreated or re-enabled; there is no setting to find because the feature no longer exists.
- Optimized Targeting is the functional replacement, but it runs as continuous, unlisted expansion rather than a static, inspectable lookalike list.
- Seed lists (remarketing, Customer Match) are still valuable - attach them as audience signals to feed optimized targeting and Smart Bidding rather than looking for a way to spawn a derived audience from them.
- When auditing an older account, check that seed lists formerly feeding a similar segment are still attached as signals somewhere, since a straight removal without re-attachment silently loses targeting value.
In practice.
Similar segments existed as a Google Ads audience type that took a seed source - a remarketing list, a Customer Match list, or another first-party audience - and automatically generated a new segment of users who shared enough behavioral and demographic signal with that seed to be considered lookalikes. Google discontinued the feature in an audience-targeting cleanup that finished in mid-2023, folding its function into automation that now runs at the campaign level rather than as a discrete audience you selected. It survives in this glossary mainly because advertisers who worked in Google Ads before 2023, or who are reading older guides, still go looking for the setting and cannot find it, and the confusion is worth resolving directly rather than leaving unexplained.
What replaced it mechanically is Optimized Targeting, which works from inside the ad group rather than as a separate segment you add. Instead of generating a static lookalike list you could inspect, name, and reuse across campaigns, optimized targeting continuously expands delivery beyond your stated audience signals in real time, using live conversion data rather than a one-time similarity calculation. The tradeoff is transparency for responsiveness: a similar segment was a fixed list you could audit and reuse, while optimized targeting is a live behavior baked into how the campaign spends that adjusts as your conversion signal accumulates, and you cannot inspect or export who is actually in the expanded pool.
The practical consequence for account structure is that your seed lists - remarketing lists and Customer Match lists especially - did not become useless when similar segments retired, they changed job. Under the old system, a seed's value was in spawning a derived lookalike audience. Now, that same seed's value is as a signal you attach directly to a Performance Max asset group or a standard campaign, feeding Smart Bidding and optimized targeting so the algorithm has a stronger starting point for who resembles your best customers. The list itself is still worth building and maintaining carefully; what changed is that you are no longer choosing a discrete lookalike product built from it.
This matters most for anyone auditing an older account that still shows historical similar segments performance in reporting, or anyone following a pre-2023 setup guide that references adding a similar audience to an ad group - that step no longer exists and should be read as "add the seed list as an audience signal and let optimized targeting handle expansion." It matters less for anyone building a new account from scratch today, since there is no migration decision to make; optimized targeting and Customer Match already sit in the default workflow without any similar-segments-shaped gap to notice.
In reporting, historical similar segments rows in an old account's audience reports are frozen artifacts from before the sunset and will not accumulate new data - they are not something to troubleshoot or reactivate. If a client or teammate asks where the lookalike audiences went, the honest answer is that Google absorbed the mechanism into campaign-level automation, and the actionable move is checking that Customer Match and remarketing lists are still attached as audience signals wherever they used to feed a similar segment, since a migration that only removed the old segment without re-attaching the seed as a signal quietly loses some of that targeting value.
Migrating an old similar-segments setup
Suppose an advertiser inherits a Google Ads account last actively managed in 2022, and the setup notes describe an ad group targeting "a similar audience built from our top 5% purchaser remarketing list," alongside performance showing that audience once drove a notably lower cost-per-acquisition than broad Display targeting.
That similar segment no longer exists in the account and cannot be recreated by name. The correct move is to locate the original top-5%-purchaser remarketing list, confirm it is still populating with recent purchasers, and attach it as an audience signal to the relevant ad group or Performance Max asset group, then let optimized targeting run its own live expansion from that seed rather than trying to replicate the old static lookalike. Performance afterward won't be directly comparable to the 2022 numbers, since the underlying mechanism generating expanded reach is now different, but the seed list's value as a signal carries forward.
Similar Segments compared with
The settings this gets confused with, and how to tell them apart.
- Similar Segments vs In-Market Audiences
- Similar Segments vs Affinity Audiences
- Similar Segments vs Custom Segments
- Similar Segments vs Customer Match
- Similar Segments vs Remarketing Lists
- Similar Segments vs Demographic Targeting
- Similar Segments vs Optimized Targeting
- Similar Segments vs Placement Targeting
- Similar Segments vs Content Keyword Targeting
Common questions.
Where did similar segments go in Google Ads?
Google discontinued similar segments in 2023 as part of a broader audience-targeting cleanup; the option no longer exists anywhere in the interface. Its function was absorbed into Optimized Targeting, which runs automatically at the campaign or ad group level instead of as a selectable audience.
How do I create a lookalike audience in Google Ads now?
There is no direct equivalent - attach your best seed list (a remarketing list or a Customer Match list) as an audience signal to a Performance Max asset group or standard campaign, and Optimized Targeting will expand delivery beyond that signal automatically using live conversion data rather than a one-time similarity calculation.
Will my old similar segments data still be in my reports?
Historical rows from before the 2023 sunset remain visible in audience reports for reference, but they are frozen and will not accumulate new impressions or conversions. Treat them as an archived record, not something to troubleshoot.
Should I rebuild my similar segments strategy using Customer Match instead?
Customer Match is the right tool for uploading a first-party seed list, but the lookalike expansion itself now happens through Optimized Targeting once that list is attached as a signal, not through a separate lookalike-building step. The two work together rather than one replacing the other.
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