Website Change Lab
What does a website change actually mean? Start with a small, controlled example. Each case below uses fictional pages and real browser captures, with its assumptions and limits attached.
Small changes. Different consequences.
The banner changed. Did the price? Monitoring a stable page region.
A reproducible monitoring example separates a rotating announcement from a real plan-price change, with region captures, selector scope and downloadable evidence.
Read the worked exampleYour selector still matches. Is it tracking the wrong product?
Two plans swap position while their prices stay the same. Inspect positional and identity selectors, a missing-target case and real browser extraction results.
Read the worked exampleAPI field missing, null or empty: what actually changed?
Four downloadable JSON fixtures distinguish an absent field, null, an empty string and a value, with recorded checks and an explicit example consumer contract.
Read the worked exampleThe desktop screenshot passed. What changed in the mobile menu?
An identical desktop view hides a missing mobile navigation link. Inspect real open-menu captures, interaction steps and responsive-testing limits.
Read the worked exampleThe price stayed $29. Why did the offer get more expensive?
A reproducible price-monitoring example: $29 per year becomes $29 per month. Inspect the fixtures, captured terms, screenshots and annual cost calculation.
Read the worked exampleOne navigation edit, three alerts. What still needs review?
Three controlled pages share one navigation edit, but only pricing gains noindex. See why grouping related changes must preserve each page's separate risk.
Read the worked exampleThe page is online. Why is its new noindex directive a release risk?
An HTTP 200 and identical screenshots hide a changed robots directive. Inspect the noindex fixture pair, actual metadata and an explicit staging exception.
Read the worked example
Open the evidence. Repeat the check.
The examples use OnChange-authored HTML fixtures, captured in Chrome on desktop and mobile. The evidence record contains timestamps, viewport sizes, file hashes, extracted text, metadata and automated findings. These are controlled demonstrations, with no customer data or claims about a real business.