The Google Merchant Center structured data documentation explains that structured data must be added to the HTML source and not generated after a page has loaded using JavaScript, although Google can still process structured data generated with JavaScript. Jarno van Driel posted about this on LinkedIn, questioning the discrepancy between Google Search Central and Google Merchant Center documentation. Google’s Ryan Levering clarified that both documents are technically correct and mentioned that Google is working to adjust the wording to resolve the discrepancy.
Levering also advised against making changes to websites that are currently working, as Google Merchant Center crawlers are able to process structured data generated with JavaScript. However, Google has observed quality issues and inconsistencies with these implementations, leading to a recommendation against using them. For example, conflicting information between the initial HTML source and JavaScript-rendered content can confuse Google’s systems. The documentation suggests that if possible, adding structured data during the original page load is more reliable.
Google had introduced documentation on structured data using JavaScript four years ago, and the topic sparked discussion on LinkedIn. Levering later clarified that Google Merchant Center’s wording may be overly harsh, as it currently states that certain actions cannot be done when, in reality, they are just recommendations.
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