diff --git a/decnet_web/vite.config.ts b/decnet_web/vite.config.ts
index 83775466..89ce888c 100644
--- a/decnet_web/vite.config.ts
+++ b/decnet_web/vite.config.ts
@@ -12,4 +12,30 @@ export default defineConfig({
       },
     },
   },
+  build: {
+    // Split heavy third-party libs into their own chunks so the main
+    // bundle stays small and the rarely-changing vendor code stays
+    // cacheable across deploys. Recharts + asciinema-player + lucide
+    // together made up most of the weight that was tripping the 500kB
+    // warning.
+    rollupOptions: {
+      output: {
+        manualChunks: (id: string) => {
+          if (!id.includes('node_modules')) return undefined
+          // d3-* ships alongside recharts as its plotting engine —
+          // grouping them keeps tree-shaken subsets together.
+          if (id.includes('recharts') || id.includes('/d3-')) return 'charts'
+          if (id.includes('asciinema-player')) return 'player'
+          if (id.includes('lucide-react')) return 'icons'
+          if (id.includes('react-router')) return 'router'
+          if (id.includes('react-dom')) return 'react-dom'
+          if (id.includes('/react/') || id.endsWith('/react')) return 'react'
+          return 'vendor'
+        },
+      },
+    },
+    // Legitimate ceiling for any single chunk after splitting; anything
+    // larger is a real bloat regression worth investigating.
+    chunkSizeWarningLimit: 600,
+  },
 })