There is no noai directive — nosnippet is the real AI lever
There is no noai directive in Google's documentation. The tag that controls what AI Overviews and AI Mode may quote is max-snippet, and Google names those surfaces explicitly.
RULE CHANGE · 2026-08-15 · Google documentation
There is no noai directive. The nosnippet AI control — nosnippet and its sibling max-snippet — is what actually governs what AI surfaces may quote from your page, and Google says so in writing. Its documentation for max-snippet states the limit "applies to all forms of search results (such as Google web search, Google Images, Discover, Assistant, AI Overviews, AI Mode)". That single sentence names the lever most site owners have never touched.
What we checked, and what does not exist
We read Google's robots meta tag documentation on 15 August 2026 and listed every directive it supports: noindex, nofollow, none, nosnippet, indexifembedded, max-snippet, max-image-preview, max-video-preview, notranslate, noimageindex, unavailable_after, and all.
noai is not among them. Neither is noimageai. Those two circulate widely as if they were standard, and Google's documentation does not mention them at all.
What the nosnippet AI control actually does
Google's wording: "Do not show a text snippet or video preview in the search results for this page. A static image thumbnail (if available) may still be visible, when it results in a better user experience."
And max-snippet: "Use a maximum of [number] characters as a textual snippet for this search result... This applies to all forms of search results (such as Google web search, Google Images, Discover, Assistant, AI Overviews, AI Mode)."
Read that list again — and note that this sits alongside, not inside, the robots.txt tokens covered in robots.txt for AI crawlers. AI Overviews and AI Mode are named explicitly. This is a documented control over what Google's AI surfaces may show from your page, and it lives in a tag that predates any of them.
The three levers, and what each one governs
Site owners routinely reach for the wrong one. These are different mechanisms with different scopes.
| Lever | Where it lives | What it governs |
|---|---|---|
Google-Extended | robots.txt | Gemini model training. Not Search inclusion, not ranking. |
nosnippet / max-snippet | meta tag or X-Robots-Tag header | How much text may be shown — including in AI Overviews and AI Mode. |
noindex | meta tag or header | Whether the page is in the index at all. The blunt instrument. |
noai | — | Does not exist in Google's documentation. |
Why this ordering matters
Someone who wants less of their content appearing verbatim in AI answers, but still wants the traffic, has been reaching for robots.txt — where the available tokens govern training, not display. The lever that governs display was in the meta tag the whole time.
And it is granular. max-snippet:50 is a different position from nosnippet: it permits a short excerpt while preventing a long one. Nothing in robots.txt offers that gradient.
The header version, for files you cannot edit
The same directives work as an HTTP header, which is the only option for PDFs and other non-HTML files.
# In the page head
<meta name="robots" content="max-snippet:120">
# Or as a response header, for any file type
X-Robots-Tag: max-snippet:120The header form is also how you apply a rule across a whole directory without touching each document.
What we cannot tell you
Whether other engines honour these directives. Google documents its own behaviour; ChatGPT, Perplexity and Claude do not publish a mapping between these tags and their citation behaviour, and we have not tested it. Treat this as a Google-side control until someone shows otherwise.
We also have not measured the traffic effect of setting max-snippet low. There is an obvious tension — a shorter snippet may mean fewer answers built from you and more clicks, or simply less visibility — and we are not going to guess which dominates.
Common questions
How did you verify this?
By reading Google's robots meta tag documentation on 15 August 2026 and quoting the directive list and the two definitions directly. We did not test the behaviour on live pages; the claim here is about what is documented, not about what we observed.
Should I set nosnippet?
Probably not, and certainly not by default. Snippets are how people decide to click. The reason to know about it is that it exists and is specific — not because most sites should use it.
Does noindex remove me from AI answers?
It removes the page from Google's index, which is what AI Overviews are built on. It is also the most expensive possible way to achieve that, because it removes you from ordinary search at the same time.
Where did noai come from then?
It has been proposed in various places and some platforms honour their own variants. What we can say is narrow and checkable: it is not in Google's documented directive list, so writing it and expecting Google to act on it is a mistake.
The one line to take away
If you want to control how much of your page an AI answer may quote, the documented lever is max-snippet, not anything in robots.txt — and the tag has governed AI Overviews all along. Deciding that, shipping it and pushing it for indexing is the part that changes what shows up.
