When Performance Claims Become a Legal Question
Core Web Vitals — Google's set of metrics measuring loading performance, interactivity, and visual stability — have become a standard reference point in web development and hosting contracts. Disputes arise when a vendor guarantees specific performance outcomes, or when a platform migration or redesign degrades performance in a way that measurably affects search visibility and revenue.
These disputes often involve a straightforward before-and-after comparison, but establishing what the site's performance actually was before a change requires historical data that not every business thinks to preserve. Where that data exists in Google Search Console or a comparable monitoring tool, it is usually decisive.
Analysis Approach
Performance disputes are, at bottom, data disputes: the question is almost always whether the historical record actually supports the specific performance claim being made, on either side, rather than a purely technical question about how a website was built.
- Historical Core Web Vitals data from Google Search Console and CrUX (Chrome User Experience Report)
- Before-and-after comparisons tied to specific platform changes or migrations
- Contractual performance guarantees against actual, measured outcomes
- Correlation between performance changes and organic traffic or ranking movement
Because Core Web Vitals are one input into ranking among many, Bill's reports are careful to state how much of a given traffic change performance issues can plausibly explain, rather than treating every drop in scores as automatic proof of measurable harm.