We Tracked 1,885 Pages Adding Schema. AI Citations Barely Moved.

AI cited pages were almost three times more likely to have JSON-LD than non-cited pages.

That's a big gap, and the kind of stat that gets shared in LinkedIn carousels and conference slides as proof that schema is an AI visibility lever.

But we weren’t satisfied with the data since it could easily have been correlation, not cause.

Schema markup tends to live on better-maintained, more technically sophisticated sites, and those same sites publish stronger content, build more authority, earn more links, and do all the other things that get pages cited.

Schema could be doing real work, but it could also just be riding the wave of every other signal.

So we couldn't actually answer the question SEOs really care about: if I add schema to my page, will I get cited more by AI?

To find out, we ran a second study designed to isolate the effect of adding schema.

Here's what we found.

We tracked 1,885 web pages that added JSON-LD schema between August 2025 and March 2026, matched them against 4,000 control pages, and measured citation changes across Google AI Overviews, AI Mode, and ChatGPT.

Adding schema produced no major uplift in citations on any platform.

These percentages come from our most reliable analysis (a matched difference-in-differences [DiD] test).

In this test, both AI Mode and ChatGPT treated pages performed slightly better than control pages on average, but the differences are small enough that they could easily be random noise across thousands of URLs.

AI Overviews showed a 4.6% decline, which is small but statistically significant relative to matched control pages.

But that isn't quite the full story—we'll get into that in the next section.

So, overall, we can't tell whether the schema did a tiny bit of good or nothing at all.

AI Overview citations on treated pages fell by 4.6% relative to control pages, and the result is "statistically significant" (the odds of seeing a gap this large by pure chance are about 1 in 2,500).

But before anyone reads this as "adding schema hurts your AI Overview citations", there are two things you need to bear in mind.

That said, if adding schema had no effect on citations either way, we'd expect treated pages and matched controls to decline together at the same rate (which is broadly what we see for AI Mode and ChatGPT).

The fact that treated pages declined slightly more suggests schema had a small negative effect—but it could also reflect other factors.

We can't tell which one it is from this data alone.

Using Brand Radar, Xibeijia pulled a few million URLs cited in AI Overviews.

She then retrieved the HTML history from our crawler database, labeled whether each URL contained <script type="application/ld+json">, and spotted the date that schema presence transitioned from "False" to "True".

This left her with 1,885 pages that introduced JSON-LD between August 2025 and March 2026.

Finally, to analyze all of that data, she used Agent A, our new AI marketing agent.

For each page Xibieijia knew two key dates:

The day a page added JSON-LD is its treatment date.

Xibeijia measured how many times each page was cited by Google AIO, Google AI Mode, and ChatGPT in the 30 days before and 30 days after the treatment date.

The tricky part of any study like this is seeing past noisy data.

Citations across all of AI search were moving during this period; AI Overviews were contracting, AI Mode was exploding.

If Xibeija had just done a simple before-and-after comparison, it would have been measuring the platform trend, not the schema effect.

So for each treated URL she picked 3 control URLs (from different domains, with similar pre-period citation levels) that had never added JSON-LD.

Comparing two groups of pages that were getting cited at the same rate before—where the only main difference was that one group added schema—made it easier to isolate what schema actually did.

We looked at the data four different ways to make sure any conclusion held up under scrutiny.

In each test, we asked a slightly different version of the question: "did schema do anything?"

You only really believe a finding when several of them agree and, in this case, they do.

Test 1: Compared average citation changes between treated and control pages (a two-sample t-test).

Test 2: Ran a difference-in-differences (DiD) analysis to strip out platform-wide trends. This is the test we trust most, and the source of the findings in this article.

Test 3: Plotted citations week-by-week to check whether treated and control pages were already drifting apart before schema was added (an event study).

Test 4: Re-ran the difference-in-differences (DiD) with a symmetrical window that excluded the recrawling period, to make sure the result wasn't sensitive to how we defined "before" and “after."

All four tests told the same story: no citation growth in AI Mode, no citation growth in ChatGPT, and a small AI Overview decline that's real but small enough that we can't definitively pin it on schema.

The most consistent finding is that not much really changed—schema had no clear positive or negative effect.

Want to know whether schema works for your site specifically? Run a smaller version of this study yourself. Brand Radar can help when it comes to tracking the course of AI citations:

If both groups moved by similar amounts, that's more to do with the platform trend than the schema.

But if treated pages outperformed controls, that's a sign schema is having a positive impact on citations.

If you run this on your own pages and get a different result to ours, let us know.

For pages already getting cited by AI, adding JSON-LD schema didn't boost citations on Google AI Mode or ChatGPT, and showed only a small decline in AI Overviews that we can't clearly attribute to schema.

So why are 53% of AI-cited pages running schema?

Because the sites that add structured data tend to also invest in technical SEO, publish authoritative content, build links, maintain their pages, and rank well in regular search.

AI systems are more likely to retrieve this kind of content, so cited pages over-index on all of those signals at once. Strip schema out and it’s very likely the rest of the signals still carry the page through to citation.

If you're already doing the rest of the SEO work well, JSON-LD isn't going to be the unlock.

There are still, of course, many good reasons to use JSON-LD schema (rich results, voice assistants, knowledge graphs, downstream entity recognition).

But if the only reason you're adding it is to get more AI citations on pages that are already visible, our data doesn't support that bet.