Try out the netlify lighthouse plugin

netlify.toml

@@ -1,3 +1,16 @@
 [build]
   publish = "_site"
   command = "npm run build"
+
+[[plugins]]
+  package = "@netlify/plugin-lighthouse"
+
+  # optional, fails build when a category is below a threshold
+  [plugins.inputs.thresholds]
+    performance = 1.0
+    accessibility = 1.0
+    best-practices = 1.0
+    seo = 1.0
+
+  [plugins.inputs]
+    output_path = "reports/lighthouse/index.html"

package.json

@@ -37,6 +37,7 @@
 		"@11ty/eleventy-navigation": "^0.3.5",
 		"@11ty/eleventy-plugin-rss": "^1.2.0",
 		"@11ty/eleventy-plugin-syntaxhighlight": "^4.2.0",
+		"@netlify/plugin-lighthouse": "^4.0.6",
 		"luxon": "^3.2.1",
 		"markdown-it-anchor": "^8.6.6"
 	}