What should an SEO deployment preview validate before a CMS page can be published?

Create a deployment health check that evaluates both content and rendered technical output.

At the page level, validate final URL/slug, title, H1, meta robots, canonical, Open Graph basics, structured data parsing, primary image availability, and required entity fields. Confirm the canonical is on the allowed client domain and that noindex is intentional.

Render the page using the same template path as production and verify that required content tokens are present. Check that important internal links resolve, no placeholder variables remain, and the page does not generate duplicate IDs or malformed markup.

At the site level, detect duplicate slugs, conflicting canonicals, orphan pages, broken navigation references, sitemap inclusion errors, and redirects pointing to drafts.

For JavaScript pages, compare source and rendered states for critical fields. For static deployments, ensure the generated artifact actually contains the expected HTML rather than trusting the editor preview.

Make warnings severity-aware. Missing optional social text may be a warning; a page-level noindex on the homepage should block publishing.

Store the validation result with the deployment so teams can audit what was checked. If an agency publishes to client-owned hosting, expose a post-deployment health test that fetches the live URL and confirms the host serves the same expected state.

The preview should answer more than "does it look good?" It should answer "is this page technically safe to publish?"