AI Search

What Triggers AI Overviews? 86 Factors and 146 Million SERPs Analyzed

Ryan Law
Ryan Law is the Director of Content Marketing at Ahrefs. Ryan has 13 years experience as a writer, content strategist, team lead, marketing director, VP, CMO, and agency founder. He's helped dozens of companies improve their content marketing and SEO, including Google, Zapier, GoDaddy, Clearbit, and Algolia. He's also a novelist and the creator of two content marketing courses.
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What triggers an AI Overview? What types of queries are most likely to generate an AIO, and which are relatively safe? Can we predict where AIOs will appear, and even target SERPs without them?

To answer these questions, we analyzed our database of 146 million SERPs and explored how often AI Overviews appeared for 86 different keyword traits, from YMYL to CPC to query length.

Across our data set, AI Overviews appear for 21% of keywords. But looking at specific keyword categories, some categories have as high as a 60% chance of triggering an AI Overview, and others as low as 1%.

  • AIOs appear on 21% of all keywords.
  • 99.9% of AIOs appear on Informational intent keywords
  • AIOs are 1.9x more common for non-branded keywords than branded keywords
  • AIOs appear on 46% of 7+ word queries
  • AIOs appear for 57.9% of all question queries
  • 44.1% of Medical YMYL queries trigger an AI Overview
  • Only 6% of news queries trigger an AI Overview
  • The categories with highest AIO share are Science (43.6%), Health (43.0%), Pets & Animals (36.8%), and People & Society (35.3%).
  • The categories with lowest AIO share are Shopping (3.2%), Real Estate (5.8%), Sports (14.8%), and News (15.1%).
  • Only 4% of NSFW queries trigger AIOs
  • Only 7.9% of local searches trigger an AI Overview
About this data

All data is from September 2025. Keyword categories are derived from our internal keyword categorization systems.

If you’re an Ahrefs user, you can access this data yourself. Just head to Keywords Explorer and use the SERP features filter to see all keywords that trigger an AI Overview, and filter by dozens of variables like intent, volume, and growth rate:

You can also analyze any brand, website, or product’s visibility in AI Overviews using Brand Radar.

Just enter your brand to analyze your mentions, citations, estimated impressions, and even share of voice across millions of AI Overviews:

AI Overviews appear on 20.5% of all SERPs (29,991,998 out of 146,122,391).

Put another way, most websites can expect to compete with a Google-branded, AI-generated blog post for 1 in every 5 of the keywords they target.

We can use this rate as a baseline to see whether different keyword characteristics—like intent, length, or CPC—make it more or less likely for AI Overviews to trigger.

Here’s a chart summarising our findings. Query types with a positive difference from the baseline (i.e. bars on the right of the mid-line) are more likely to trigger an AI Overview; those with a negative difference (bars on the left) are less likely to trigger an AI Overview.

99.9% of keywords that trigger AI Overviews are Informational in intent. 5.5% of AIO keywords are considered Commercial, 1.2% Transactional, and just 0.1% Navigational.

Sidenote.
Keywords can have multiple intent classifications, hence the total summing to greater than 100%.
IntentCountPercentage
Informational29,959,54299.9%
Navigational26,4130.1%
Commercial1,657,5605.5%
Transactional366,4001.2%

Relative to the baseline rate of 20.5%, we can see that AIOs are slightly more likely to appear for Informational keywords, but vastly less likely to appear for other intent types, especially Navigational. Just 0.09% of Navigational keywords trigger an AI Overview:

IntentAIO SERPsTotal SERPsPercentage
Informational2995954214028729021.4%
Navigational2641329099890.9%
Commercial1657560381174654.3%
Transactional366400178064002.1%

76.3% of keywords that trigger AIOs are considered non-branded (e.g. seo tools), with the remaining 23.7% categorised as branded searches ( e.g. Ahrefs).

LabelCountPercentage
Branded7,095,16023.7%
Non-branded22,896,83876.3%

AIOs are 1.9x more likely to appear on non-branded queries, triggering on 13.1% of all branded queries and 24.9% of non-branded queries in our SERP database.

LabelAIO SERPsTotal SERPsPercentage
Branded70951605415052413.1%
Non-branded228968389197186724.9%

Compared to the baseline, AI Overviews rarely appear for 1-3 word queries, but often trigger for 5-7+ word queries.

It seems that the longer the search query, the greater the chance an AI Overview will appear. AIOs appear on just 9.5% of single-word queries, but that figure jumps to 46.4% of all queries with seven or more words.

Query lengthAIO SERPsAll SERPsPercent
147169149645889.50%
22537067255947779.90%
357402614093153714.00%
463151783236581419.50%
553214581930320627.60%
639356721075323336.60%
7+56706711220923646.40%

66.5% of keywords that trigger AIOs are categorized as questions.

LabelCountPercentage
Question10,045,91333.5%
Not question19,946,08566.5%

In total, AIOs appear on 57.9% of all question queries, while non-question queries show a lower rate of AI Overviews compared with the baseline, at 15.5%.

LabelAIO SERPsAll SERPsPercent
Question100459131736145157.90%
Not question1994608512876094015.50%

There seems to be little obvious correlation between keyword CPC buckets and AI Overview appearance, with most hovering within a couple of percentage points of our 20.5% baseline:

CPC (USD)AIO SERPsAll SERPsPercent
0.00-0.102427764878781827.6%
0.10-0.20847079457322818.5%
0.20-0.5017408081405733712.4%
0.50-1.5024352721355027618%
1.50-5.001511232770948919.6%
5.00-20.00302047157672319.2%
20.00+2094313285215.8%

Almost a third (32.3%) of the keywords that trigger AI Overviews are categorised as YMYL (Your Money or Your Life) queries.

Given that YMYL queries are—according to Google themselves—deserving of extra care and attention, it seems surprising to see AI-generated answers so prevalent.

In fact, AI Overviews are more common for YMYL queries than normal queries. 34.3% of all YMYL queries trigger an AI Overview, far higher than our 20.5% baseline. Non-YMYL queries are less likely to trigger AIOs, at just 17.2%:

LabelAIO SERPsAll SERPsPercent
Not YMYL2029137211784346417.2%
YMYL97006262827892734.3%

All YMYL categories—Medical, Financial, Safety, Legal, and Other—show an increased occurrence of AI Overviews.

This is especially true for Medical YMYL queries, with 44.1% of medical queries triggering an AI Overview—more than double the frequency at which AI overviews appear across all keywords.

CategoryAIO SERPsAll SERPsPercent
Not YMYL2029137211784346417.2%
Medical59248661343026344.1%
Financial2027902885939722.9%
Safety1215129392297731%
Legal354573149985523.6%
Other17815656643531.5%

This has not gone unnoticed by SEOs in the healthcare industry:

If we categorise keywords by the industry they belong to, we can see that AI Overviews have hit some industries harder than others.

Compared to our baseline of 20.5%, the hardest hit categories are:

  1. Science (43.6%)
  2. Health (43.0%)
  3. Pets & Animals (36.8%)
  4. People & Society (35.3%)
  5. Internet & Telecom (30.3%)
  6. Reference (30.1%)
  7. Computers & Electronics (28.6%)

At the other end of the spectrum, AI Overviews seem unlikely to trigger for other industries, especially those related to commerce and news content:

  1. Shopping (3.2%)
  2. Real Estate (5.8%)
  3. Sports (14.8%)
  4. News (15.1%)
CategoryAIO SERPsAll SERPsPercent
Adult4410635993111.2%
Arts_and_Entertainment18827951400977413.4%
Autos_and_Vehicles1269893676238018.8%
Beauty_and_Fitness859603467915718.4%
Books_and_Literature317298152653920.8%
Business_and_Industrial936352575741216.3%
Computers_and_Electronics1675947586296428.6%
Finance1355373545199324.9%
Food_and_Drink1804833968018218.6%
Games736028536207013.7%
Health66381821543692743%
Hobbies_and_Leisure303138225679313.4%
Home_and_Garden1755813954044618.4%
Internet_and_Telecom377053124450130.3%
Jobs_and_Education1092337607531918%
Law_and_Government898760388973923.1%
News746414494873515.1%
Online_Communities218816107130620.4%
People_and_Society1665904472262335.3%
Pets_and_Animals1179593320371736.8%
Real_Estate17019929162115.8%
Reference1140509378683430.1%
Science1281223293942743.6%
Sensitive_Subjects131358124259810.6%
Shopping555271173434823.2%
Sports964484651923114.8%
Travel_and_Transportation1050155667509115.7%

Almost all keywords that trigger AI Overviews fall into the not newsy category, with just 0.2% of keywords categorised as very newsy.

CategoryCountPercentage
Not newsy28,256,71694.2%
Somewhat newsy1,714,8655.7%
Very newsy20,4170.07%

Relative to the 20.5% overall AIO rate, very newsy keywords are significantly less likely to trigger an AI Overview, suggesting that AIOs concentrate on evergreen queries, not current news.

CategoryAIO SERPsAll SERPsPercent
not_newsy2825671613618164220.7%
somewhat_newsy1714865961892617.8%
very_newsy204173218236.3%

As part of a bug bounty, Mark Williams-Cook found a series of query classifiers used by Google as part of their search systems. (Learn more here.)

All but one of these categories (other) are much more likely than average to trigger an AI Overview. At the extreme, 59.8% of all reason queries trigger an AI Overview, the greatest percentage of any category in this research.

CategoryAIO SERPsAll SERPsPercent
other6999483919324247.6%
short_fact64621551570031341.2%
definition52088951100113147.3%
reason4603040769696259.8%
instruction43943321252150735.1%
comparison1292772494256726.2%
bool772554134663057.4%
consequence21977047043446.7%

AI Overviews generally don’t trigger for NSFW queries. 99.1% of the queries that trigger AIOs are classified as not NSFW:

Only 4% of NSFW queries trigger an AI Overview, far lower than our baseline occurrence:

CategoryAIO SERPsAll SERPsPercent
Not NSFW2973235613963677721.4%
NSFW25964264856144%

Relative to the 20.5% overall AIO rate, all NSFW categories show a significantly lower incidence of AI Overviews. Within NSFW, the highest AIO rates are observed for drug queries (12.6%) and scam queries (11.3%), though both remain well below the baseline.

CategoryAIO SERPsAll SERPsPercent
not_nsfw2973235613963677721.3%
drugs9277173581412.6%
adult5645037417041.5%
violence428055544577.7%
weapons188983544545.3%
vulgar181371928529.4%
illegal97061903875.1%
gambling84125822591.4%
scams66835935711.3%
hate3243413377.8%
self_harm2537329937.7%

AI Overviews seem unlikely to trigger for local searches (e.g. dentist near me).

AIOs appear for just 7.9% of queries categorised as local searches, well below the base rate of 20.5% across all keywords, and for 22.8% of non-local queries, slightly above the base rate.

CategoryAIO SERPsAll SERPsPercent
local1757205223581477.9%
non_local2823479312376424422.8%

Google acknowledges four types of user intent in its Search Quality Evaluator Guidelines:

  • Know query, some of which are Know Simple queries
  • Do query, when the user is trying to accomplish a goal or engage in an activity
  • Website query, when the user is looking for a specific website or webpage
  • Visit-in-person query, some of which are looking for a specific business or organization, some of which are looking for a category of businesses

99.9% of the keywords that trigger AIOs fall into the “Know” category, suggesting strong overlap between Know keywords and our definition of Informational keywords (which also account for 99.9% of AIO triggering keywords). Google seems unlikely to trigger AIOs for other intent types.

CategoryCountPercentage
know29,959,54999.9%
do2,755,5189.2%
visit_in_person628,1882.1%
website26,4110.1%

Do, Visit-in-person, and Website all trigger AIOs less frequently than the base rate, with Website queries returning them less than 1% of the time.

The Visit in person AIO rate is virtually on par with our Local queries category (7.1% and 7.9% AIO rate respectively); and the Website AIO rate is identical to our Navigational classification from earlier (both returning an AIO rate of 0.9%).

CategoryAIO SERPsAll SERPsPercent
know2995954914028727421.4%
do27555182116898613%
visit_in_person62818888137997.1%
website2641129099830.9%

Final thoughts

It seems crystal clear that AI Overviews are designed to trigger for informational queries, particularly questions and long queries. They are unlikely to trigger for news queries, local searches, and NSFW queries.

But more surprising: AI Overviews trigger very frequently for YMYL queries, and especially medical YMYL queries. Despite obvious risks of hallucination, Google seems perfectly happy answering crucial medical queries with an AI-generated snippet.

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