diff --git a/.changeset/quick-apes-grab.md b/.changeset/quick-apes-grab.md
new file mode 100644
index 00000000000..94ab57bec1f
--- /dev/null
+++ b/.changeset/quick-apes-grab.md
@@ -0,0 +1,7 @@
+---
+"@astrojs/starlight": patch
+---
+
+Fixes invalid `` output when configuration is missing:
+- Omits `` if Starlight’s `description` option is unset
+- Omits `` and `` if Astro’s `site` option is unset
diff --git a/packages/starlight/utils/head.ts b/packages/starlight/utils/head.ts
index 0f3095e6bea..b956c3602f1 100644
--- a/packages/starlight/utils/head.ts
+++ b/packages/starlight/utils/head.ts
@@ -33,7 +33,9 @@ export function getHead(
attrs: { name: 'viewport', content: 'width=device-width, initial-scale=1' },
},
{ tag: 'title', content: `${data.title} ${config.titleDelimiter} ${siteTitle}` },
- { tag: 'link', attrs: { rel: 'canonical', href: canonicalHref } },
+ ...(canonicalHref !== undefined
+ ? ([{ tag: 'link', attrs: { rel: 'canonical', href: canonicalHref } }] as const)
+ : []),
{ tag: 'meta', attrs: { name: 'generator', content: context.generator } },
{
tag: 'meta',
@@ -51,9 +53,13 @@ export function getHead(
// OpenGraph Tags
{ tag: 'meta', attrs: { property: 'og:title', content: data.title } },
{ tag: 'meta', attrs: { property: 'og:type', content: 'article' } },
- { tag: 'meta', attrs: { property: 'og:url', content: canonicalHref } },
+ ...(canonicalHref !== undefined
+ ? ([{ tag: 'meta', attrs: { property: 'og:url', content: canonicalHref } }] as const)
+ : []),
{ tag: 'meta', attrs: { property: 'og:locale', content: lang } },
- { tag: 'meta', attrs: { property: 'og:description', content: description } },
+ ...(description !== undefined
+ ? ([{ tag: 'meta', attrs: { property: 'og:description', content: description } }] as const)
+ : []),
{ tag: 'meta', attrs: { property: 'og:site_name', content: siteTitle } },
// Twitter Tags
{