SEO expert testimony is the written report, the deposition and the trial testimony an expert gives about search engine optimization (SEO) evidence: what happened to a website’s rankings and traffic, when it happened, why, and what the surviving data can prove. I am Bill Hartzer, and I provide that testimony as an SEO expert witness. I write expert reports and rebuttal reports, sit for deposition, and testify at trial and in arbitration, for plaintiffs and for defendants.
This page covers the three stages of SEO expert testimony in the order counsel meets them, and then the part most attorneys come here for: the cross-examination questions an SEO expert should be ready to answer, and why each one is asked. The standards the testimony has to meet, including Federal Rule of Evidence 702 and Federal Rule of Civil Procedure 26, are covered in detail on the SEO expert witness page.
What an SEO expert witness report contains
In federal court, a retained expert’s report is governed by Federal Rule of Civil Procedure 26(a)(2)(B). It must contain a complete statement of every opinion and the basis and reasons for it, the facts or data considered, the exhibits that will summarize or support the opinions, the expert’s qualifications and publications from the previous ten years, every case in which the expert testified at trial or by deposition in the previous four years, and the compensation being paid. State courts vary, and some require far less, but a report written to the federal standard survives anywhere.
For an SEO report, those requirements translate into specific content:
- The question being answered, stated narrowly: causation, standard of care, reconstruction of what a page or search result looked like on a date, or valuation of search visibility.
- Every data source, with its date range and how it was obtained: Google Search Console exports, Google Analytics 4 (GA4) data, raw server and CDN logs, crawls, archive captures, and any third-party tool data.
- A clear separation between first-party measurement (Search Console, analytics, logs) and modeled estimates from tools such as Semrush, Ahrefs and Majestic, with a statement of what each estimate can and cannot support.
- The method, described so that another competent analyst could re-run it and reach the same result: date ranges, exclusions, controls for algorithm updates and seasonality, and the comparison used.
- The opinions, each tied to the evidence that supports it, and a statement of what the expert is deliberately not opining on.
- Exhibits built as summaries of admissible data rather than illustrations, so they can be offered under Federal Rule of Evidence 1006.
A report that cannot be reproduced from its own stated inputs is the report most likely to be excluded. That is the standard I write to.
Rebuttal reports against another SEO expert
A rebuttal report answers the opposing expert’s opinions rather than the underlying dispute. In federal court it is ordinarily due within 30 days of the other side’s expert disclosure under Rule 26(a)(2)(D)(ii), unless the court sets a different schedule, which makes the timeline tight.
Most SEO rebuttal work comes down to a short list of recurring faults in the other report:
- Treating rank-tracker positions or tool traffic estimates as measured fact when first-party data existed and was not used.
- Comparing a before period to an after period without controlling for Google core updates, seasonality or changes in search demand.
- Choosing a date window that produces the desired answer and would not survive a shift of a few weeks in either direction.
- Ignoring the growth of AI Overviews and zero-click searches when comparing traffic across 2023 to the present.
- Offering an opinion on standard of care measured against today’s practices rather than the practices that existed on the date of the conduct.
- Converting a traffic estimate into dollars without the economic analysis that conversion requires.
A good rebuttal report does not merely disagree. It re-runs the opposing analysis with the missing controls and shows what changes.
Deposition of an SEO expert witness
The deposition is where the report is tested. In federal court it is limited by default to one day of seven hours under Rule 30(d)(1), and under Rule 26(b)(4)(E) the party taking the deposition ordinarily pays the expert’s reasonable fee for the time spent. Opposing counsel uses the deposition to lock in the limits of each opinion, to find data the expert did not review, and to collect admissions for a motion to exclude.
Preparation for an SEO deposition is mostly preparation of the record: knowing exactly which exports, crawls and logs were considered, being able to explain why each date range was chosen, and having re-checked every figure in the report against its source. Rule 26(a)(2)(B) requires disclosure of the facts or data considered, not merely relied upon, so I keep an ordered work log of every query, crawl and export and produce it.
Trial testimony
At trial the audience changes from opposing counsel to the judge or jury, and the task changes from defending the record to explaining it. Search evidence is unfamiliar to most jurors, so the testimony has to define terms such as organic search, indexing, canonical tags and backlinks in plain language before using them, and it has to rest on exhibits that show the data rather than characterize it.
I have testified at trial and been deposed in state, federal and international matters, including United States Federal District Court and the Grand Court of the Cayman Islands. The current list of matters in which I testified at trial or by deposition in the previous four years is provided on retention, as Rule 26 requires.
Cross-examination questions for an SEO expert witness
These are the questions an SEO expert witness should expect on cross-examination, grouped by what they are designed to establish. Counsel cross-examining an SEO expert can use them as a starting outline. Counsel retaining one can use them to test a candidate before the other side does.
Qualifications and current practice
- When did you last perform SEO work for a client who was not a party to litigation? Experience that ended years ago is experience in a different search engine.
- What portion of your income comes from expert witness work? A witness who no longer practices is easier to portray as a professional testifier.
- Have you ever been excluded or had an opinion limited by a court? The answer must be accurate, because it is checkable.
- Which of your own articles, posts or presentations from the last ten years discuss this subject? Prior public statements are a primary source of impeachment, and Federal Rule of Evidence 803(18) allows statements from reliable published authorities to be read into the record.
Data and sufficiency
- Did you review the party’s own Google Search Console data, analytics and server logs? If not, why not? Under Rule 702(b) an opinion must rest on sufficient facts or data.
- Which figures in your report are measured, and which are estimates produced by a third-party tool? Can you explain how that tool produces its estimate?
- What data did you request that you did not receive, and how did its absence affect your opinions?
- Who selected the date ranges in your analysis, and what happens to your conclusion if each range moves by thirty days?
- Did counsel provide any facts or assumptions that you relied on? Those communications are discoverable under Rule 26(b)(4)(C).
Method and reliability
- Can another analyst reproduce your results from the data and steps described in your report?
- What is the error rate of your method, and how did you measure it?
- Is your method generally accepted among SEO practitioners, and where is it published?
- How did you account for Google core updates released during the period you analyzed?
- How did you account for seasonality, changes in search demand, and the growth of AI Overviews and zero-click results?
Causation
- Is the timing of the traffic decline your only evidence that the defendant caused it?
- Did you compare the affected pages with unaffected pages on the same site, or with competitors over the same period?
- Did any other channel, such as direct, email or paid traffic, decline at the same time? If so, how does that fit your explanation?
- What alternative causes did you consider and rule out, and what evidence did you use to rule each one out?
- Are you offering an opinion on the dollar value of the loss, and are you qualified to perform that calculation?
Standard of care
- What written standard defines competent SEO practice on the date of the conduct?
- Is Google’s published guidance a standard of care, or a set of recommendations from one search engine?
- Would the practices you criticize have been considered acceptable at the time they were performed?
- Have you used any of the practices you criticize in your own client work?
Exhibits and authentication
- How was each screenshot created, by whom, and on what date? Can you show that it has not been altered?
- For each Internet Archive capture, what is the exact capture date, and does it show the page as it appeared to users or as the archive’s crawler retrieved it?
- Is this chart a summary of admissible data, or an illustration of your argument?
An expert who can answer every question in this list without hesitation, and with a document to point to, is an expert whose opinions are likely to reach the jury. An expert who cannot is a candidate for a motion to exclude.
Related expert testimony
SEO testimony often sits alongside other disciplines in the same matter. Damages testimony on lost organic traffic is covered on the SEO damages expert page. Paid search disputes are covered on the Google Ads expert witness page and broader advertising disputes on the online advertising expert witness page. Analytics evidence is covered on the web analytics expert witness page, and past engagements are listed under retained cases.
Frequently asked questions
What is SEO expert testimony?
SEO expert testimony is opinion evidence from a qualified expert about search engine optimization: why a website’s rankings or traffic changed, whether SEO work met the standard of care at the time, what a website or search result looked like on a given date, or what search visibility was worth. It is delivered through a written report, a deposition and, if the case is tried, testimony at trial.
What should an SEO expert witness report include?
In federal court, the report must meet Rule 26(a)(2)(B): every opinion with its basis and reasons, the facts or data considered, supporting exhibits, the expert’s qualifications and ten-year publication list, a four-year list of prior testimony, and the compensation paid. For SEO work it should also separate first-party data from third-party estimates and describe the method well enough to be reproduced.
What questions are asked when cross-examining an SEO expert?
Cross-examination of an SEO expert usually targets current practice, whether the party’s own Search Console and analytics data was used, whether figures are measured or estimated, how algorithm updates and seasonality were controlled, whether timing is the only evidence of causation, and how each exhibit was created and authenticated. The full list is in the cross-examination section above.
Can an SEO expert calculate damages?
An SEO expert can establish whether the conduct caused a loss of traffic or visibility and estimate the size of that loss. Converting lost traffic into dollars, including margins, mitigation and present value, is normally the work of an economist or accountant who takes the traffic analysis as an input. Keeping the two opinions separate makes both harder to attack.
Do you testify for plaintiffs or defendants?
Both. I take plaintiff and defense engagements and write rebuttal reports against other experts in this field.
How do I engage you for SEO expert testimony?
The first call is a conflict check and a short conversation about what the dispute turns on, at no charge. Engagements usually begin on a consulting basis, so the data can be examined before anyone commits to a testifying designation. Call 214-236-4378 or use the contact page.