How Google Ads match types decide which searches trigger your ads

The keyword match type sets how closely a person's search has to relate to a keyword before the ad can be considered for the auction.

Google's Help documentation describes three match types, a priority order for when several keywords fit one search, a separate set of rules for negative keywords, and, for campaigns that switch on AI Max, a further layer that changes how keywords are prioritised. This article sets out how those parts fit together and which to check first.

What broad, phrase and exact match each allow

Broad match is the default for every keyword. Its syntax is simply the keyword typed with no symbols. Google's Help page says ads can show on related searches, including ones that do not contain the keyword's direct meaning. The page also says broad match may take into account a user's recent searches, the content of landing pages and assets, and other keywords in the ad group.

Phrase match uses quotation marks, for example "tennis shoes". Ads can show on searches that include the keyword's meaning, including more specific versions of it. It reaches more searches than exact match and fewer than broad match.

Exact match uses square brackets, for example [red shoe]. Ads can show on searches with the same meaning or intent as the keyword. Google describes it as the option with the most control and the fewest searches.

The types nest. Broad match captures the queries that phrase and exact match would, plus related searches beyond them. Moving from exact to broad therefore adds reach and does not swap one set of searches for another.

Which keyword is used when several match one search

A single search can fit more than one keyword, sometimes in different ad groups. Google's Help page sets out an order for choosing between them.

First, an exact match keyword that is identical to the search term is prioritised over broad or phrase keywords and over Performance Max. Second, phrase and broad match keywords share priority with an identical Performance Max search theme. Third, if a search could match several ad groups, only the most relevant ones are considered. Fourth, when keywords share equal priority, the ad or asset group that generates the ad with the highest Ad Rank is prioritised.

Duplicates are handled the same way. Google treats the broad match keywords 'red car' and 'car red' as duplicates and uses the one with the higher Ad Rank.

For an account, this means an identical exact match keyword takes priority over broad or phrase keywords for that same search.

Why Google ties broad match to Smart Bidding

Google's documentation is direct on this point: "It's critical to use Smart Bidding with broad match." The reasoning given is that Smart Bidding sets a bid for each query using signals available at auction time, so that each query's bid reflects its own contextual signals.

The same page recommends Smart Bidding with all match types, so that bidding is optimised for the stated performance objective.

Google says Smart Bidding works best with broad match because the wide set of searches allows it to learn what works best for you.

How negative keywords differ from positive ones

Negative keywords block searches, and they use their own matching rules. In Search campaigns, a broad negative blocks the ad only when a search contains all the negative terms, in any order. Google's example is the negative "running shoes": the search "blue running shoes" is blocked, but "running shoe" is not.

A phrase negative blocks the ad when the terms appear together in the same order, with extra words allowed. "Blue running shoes" is blocked; "shoes running" is not. An exact negative blocks only a search that is exactly those terms, so "blue running shoes" gets through.

Negatives do not stretch. Google states that negative keywords will not match close variants or other expansions, so singular and plural forms and synonyms have to be added separately. Google also notes that negatives after the 16th word of a long search phrase are not applied.

In Display and Video campaigns the logic changes: negatives exclude content on a topic strongly related to the terms, and a maximum of 1,000 negative keywords is considered at the account level.

Negatives do not stretch: singular and plural forms and synonyms have to be added separately.

What AI Max changes about keywords

AI Max is a setting on existing Search campaigns and not a new campaign type. Turning it on also turns on search term matching, which Google says uses broad match, asset-based and landing page-based technology to find searches beyond the keyword list, building on the campaign's keywords, creatives and URLs. Search term matching can be switched off in ad group settings.

Keyword prioritisation changes under AI Max. Google's page says broad keywords are not treated as exact match keywords in prioritisation when the broad match campaign setting is turned off or the campaign moves to AI Max. To keep the earlier behaviour, advertisers can add copies of their exact match keywords to the AI Max campaign. Google adds that converting broad keywords to exact removes their historical keyword statistics.

Control over where ads land and appear sits in separate settings. Brand inclusions can be set at campaign and ad group level, while brand exclusions are campaign-level only. URL inclusions are set per ad group and URL exclusions per campaign. Google also says AI Max won't be effective when a campaign is limited by budget, and an alert appears in that case.

What to check first in the search terms report

The search terms report shows the searches that triggered ads and drew impressions and clicks. It lists terms used by a significant number of people, and Google omits low-volume queries for data privacy reasons, so the report does not account for every search.

Its match type column shows how closely each search relates to the keyword that triggered it, and labels close variants, meaning searches with the same meaning and intent. Under AI Max, the same report shows an "AI Max" match type and a source column that says whether a match came from broad match expansion or from keywordless matching.

Search terms insights group searches into themes and subthemes. Google says the labels come from the last 56 days of data, so they can include terms that are no longer serving or are excluded, and conversion counts can differ slightly from the report because of conversion lag.

Google suggests reading the report for irrelevant searches and adding them as negative keywords. Singular, plural and synonym versions must be added separately, and the match type of existing keywords can be edited.