{
  "schemaVersion": "crawler-atlas-1",
  "atlasVersion": "atlas-2026-07-28-v1",
  "canonical": "/atlas/hydration",
  "title": "Hydration",
  "category": {
    "slug": "rendering",
    "title": "Rendering and client execution"
  },
  "definition": "Hydration attaches client behavior to HTML that was already rendered on the server.",
  "mechanism": "When implemented well, the response contains meaningful content and crawlable links while JavaScript adds interactivity without replacing the document’s semantic core.",
  "validation": "Disable JavaScript and verify that the page remains readable and navigable, then detect whether hydration unexpectedly removes or rewrites canonical elements.",
  "commonFailure": "Hydration mismatches can replace correct server markup with an error, duplicate content, or a different link graph.",
  "related": [
    "/atlas/server-rendering",
    "/atlas/progressive-enhancement"
  ],
  "modified": "2026-07-28"
}