diff --git a/src/devReload.ts b/src/devReload.ts
new file mode 100644
index 000000000..ab4cbaac7
--- /dev/null
+++ b/src/devReload.ts
@@ -0,0 +1,45 @@
+import { WorldRendererThree } from 'prismarine-viewer/viewer/lib/worldrendererThree'
+import { isMobile } from './menus/components/common'
+
+if (process.env.NODE_ENV === 'development') {
+  if (sessionStorage.lastReload) {
+    const [rebuild, reloadStart] = sessionStorage.lastReload.split(',')
+    const now = Date.now()
+    console.log(`rebuild + reload:`, `${+rebuild} + ${now - reloadStart} = ${((+rebuild + (now - reloadStart)) / 1000).toFixed(1)}s`)
+    sessionStorage.lastReload = ''
+  }
+
+  const autoRefresh = () => {
+    window.noAutoReload ??= false
+    new EventSource('/esbuild').onmessage = async ({ data: _data }) => {
+      if (!_data) return
+      const data = JSON.parse(_data)
+      if (data.update) {
+        console.log('[esbuild] Page is outdated')
+        document.title = `[O] ${document.title}`
+        if (window.noAutoReload || localStorage.noAutoReload) return
+        if (localStorage.autoReloadVisible && document.visibilityState !== 'visible') return
+        sessionStorage.lastReload = `${data.update.time},${Date.now()}`
+        location.reload()
+      }
+      if (data.replace) {
+        console.log('[esbuild hmr] Reloading', data.replace.type, data.replace.path)
+        switch (data.replace.type) {
+          case 'mesher': {
+            if (!worldView || !viewer.world.version || !(viewer.world instanceof WorldRendererThree)) return
+            viewer.world.doHmr()
+          }
+        }
+      }
+    }
+  }
+  autoRefresh()
+
+  // mobile devtools
+  if (isMobile()) {
+    // can be changed to require('eruda')
+    //@ts-expect-error
+    import('https://cdn.skypack.dev/eruda').default.init()
+    console.log('JS Loaded in', Date.now() - window.startLoad)
+  }
+}