AI Search Crawlers Ignore JavaScript-Injected Links While Google Barely Touches Them Either
TLDR
A controlled experiment published in Search Engine Land found that AI search crawlers and Google's indexing bot fail to follow JavaScript-injected links, making JavaScript-dependent navigation a critical visibility problem across AI search and organic results.
Optimixed Overview
Optimixed's original report on this story.
Search Engine Land reports on a controlled experiment with stark results: AI assistant crawlers like GPTBot and ClaudeBot do not execute JavaScript at all and found zero JavaScript-linked pages, while Google's Googlebot—the crawler that actually builds the search index—reached only 2% of pages behind JavaScript injection. The test split a 1,062-page Brazilian business directory in half, with one set of internal links hard-coded in HTML and the other injected by JavaScript after page load, then logged all bot requests over 41 days. Only Google's GoogleOther renderer passed the JavaScript test (66% of HTML and 48% of JS pages), but that crawler feeds a different system than search indexing; for actual search visibility, the critical metric is Googlebot's dismal 2% coverage of JavaScript-linked hierarchy pages, suggesting site owners relying on client-side rendering for navigation may be invisible to both AI assistants and Google's indexing pipeline.