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%.

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:

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%:
| Label | AIO SERPs | All SERPs | Percent |
|---|---|---|---|
| Not YMYL | 20291372 | 117843464 | 17.2% |
| YMYL | 9700626 | 28278927 | 34.3% |

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.
| Category | AIO SERPs | All SERPs | Percent |
|---|---|---|---|
| Not YMYL | 20291372 | 117843464 | 17.2% |
| Medical | 5924866 | 13430263 | 44.1% |
| Financial | 2027902 | 8859397 | 22.9% |
| Safety | 1215129 | 3922977 | 31% |
| Legal | 354573 | 1499855 | 23.6% |
| Other | 178156 | 566435 | 31.5% |

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

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.
| Category | AIO SERPs | All SERPs | Percent |
|---|---|---|---|
| other | 6999483 | 91932424 | 7.6% |
| short_fact | 6462155 | 15700313 | 41.2% |
| definition | 5208895 | 11001131 | 47.3% |
| reason | 4603040 | 7696962 | 59.8% |
| instruction | 4394332 | 12521507 | 35.1% |
| comparison | 1292772 | 4942567 | 26.2% |
| bool | 772554 | 1346630 | 57.4% |
| consequence | 219770 | 470434 | 46.7% |

- 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.
| Category | Count | Percentage |
|---|---|---|
| know | 29,959,549 | 99.9% |
| do | 2,755,518 | 9.2% |
| visit_in_person | 628,188 | 2.1% |
| website | 26,411 | 0.1% |

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%).
| Category | AIO SERPs | All SERPs | Percent |
|---|---|---|---|
| know | 29959549 | 140287274 | 21.4% |
| do | 2755518 | 21168986 | 13% |
| visit_in_person | 628188 | 8813799 | 7.1% |
| website | 26411 | 2909983 | 0.9% |

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.
Further reading
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