Ensuring that content and navigation relying on JavaScript remain accessible to search engines.
JavaScript SEO is the work of making JavaScript-dependent pages understandable and accessible to search systems. It concerns what a crawler can discover, request and render, and what useful content remains in the resulting page. Using JavaScript is not itself proof of an SEO problem.
Google can execute JavaScript, but implementation details matter. Important links should be discoverable, resources need to be accessible, and the rendered page should contain the intended content and metadata. A visible app shell or loading message is not a substitute for the actual page information.
Investigate one concrete failure at a time. A page might be missing links, returning the wrong status, failing to load data or changing its metadata inconsistently. Naming the failure helps a developer choose a repair. Recommending a complete framework replacement before examining the output can add work without establishing the cause.
Takeaway: Test what the page delivers and renders before blaming or replacing its technology. Focus on the main content, navigation and metadata that customers and search systems need.
Example
A catalog category loads products after a data request. The page opens normally in a developer’s session, but an anonymous request receives an error from the data source. A rendering check shows an empty category. The repair should address that access or loading issue rather than merely add more keywords to the category heading.
What to check
Compare the initial HTML, rendered output and relevant response status for a representative URL. Review crawlable links and resource failures. Server rendering or pre-generation may help in some architectures, but neither removes the need for correct output and testing.
For more detail, see Understand the JavaScript SEO basics.