Technical eligibility, control 5 of 20
T-05 Verify rendering on each target surface
Critical content must be reliably accessible to the relevant consumer. JavaScript is not inherently an SEO failure; raw HTML, rendered DOM and agent-browser access are separate observations.
- Priority
- Gate. A FAIL stops publish or launch.
- Hard gate
- Yes. A FAIL stops publication, whatever the score.
- Change class
- AUTO_WITH_TEST: A candidate requiring relevant tests.
- Quality bucket
- Technical eligibility
Why it matters
If key content or links only appear after fragile scripts run, users on slow or failing devices may see an empty page. Crawlers may also miss the title, text or links entirely. Content that search engines and AI answer engines cannot see cannot be indexed, summarised or cited.
Evidence to review
- Initial HTML, final DOM, console/network errors and target-engine inspection when available.
How to implement
- Check initial response, hydrated page and delayed network dependencies.
- Do not rely on JavaScript to remove an initial noindex for intended indexing.
- Keep canonical signals stable before and after rendering.
- Prefer resilient HTML delivery where useful, without claiming every AI fetcher executes JavaScript.
How UltimateSEO checks this
Automated. A check in the scan sets PASS or FAIL for this control, and reports UNKNOWN or BLOCKED when its input is missing.
States used: PASS, FAIL, UNKNOWN, NOT_APPLICABLE or BLOCKED. UNKNOWN is never shown as a pass. How states work.
Sources
- [G12] JavaScript SEO basics
Part of The UltimateSEO Framework v4.3, catalogue dated 2026-10-14. Evidence states, control states and the publish gate are explained on the hub.