diff --git a/apps/ui/eslint.config.mjs b/apps/ui/eslint.config.mjs
index d7bc54d4..6db837e3 100644
--- a/apps/ui/eslint.config.mjs
+++ b/apps/ui/eslint.config.mjs
@@ -70,6 +70,8 @@ const eslintConfig = defineConfig([
         AbortSignal: 'readonly',
         Audio: 'readonly',
         ScrollBehavior: 'readonly',
+        URL: 'readonly',
+        URLSearchParams: 'readonly',
         // Timers
         setTimeout: 'readonly',
         setInterval: 'readonly',
diff --git a/apps/ui/src/components/views/board-view/dialogs/create-pr-dialog.tsx b/apps/ui/src/components/views/board-view/dialogs/create-pr-dialog.tsx
index a8ba8ee5..3abbb75f 100644
--- a/apps/ui/src/components/views/board-view/dialogs/create-pr-dialog.tsx
+++ b/apps/ui/src/components/views/board-view/dialogs/create-pr-dialog.tsx
@@ -117,7 +117,7 @@ export function CreatePRDialog({
               description: `PR already exists for ${result.result.branch}`,
               action: {
                 label: 'View PR',
-                onClick: () => window.open(result.result!.prUrl!, '_blank'),
+                onClick: () => window.open(result.result!.prUrl!, '_blank', 'noopener,noreferrer'),
               },
             });
           } else {
@@ -125,7 +125,7 @@ export function CreatePRDialog({
               description: `PR created from ${result.result.branch}`,
               action: {
                 label: 'View PR',
-                onClick: () => window.open(result.result!.prUrl!, '_blank'),
+                onClick: () => window.open(result.result!.prUrl!, '_blank', 'noopener,noreferrer'),
               },
             });
           }
@@ -251,7 +251,10 @@ export function CreatePRDialog({
               <p className="text-sm text-muted-foreground mt-1">Your PR is ready for review</p>
             </div>
             <div className="flex gap-2 justify-center">
-              <Button onClick={() => window.open(prUrl, '_blank')} className="gap-2">
+              <Button
+                onClick={() => window.open(prUrl, '_blank', 'noopener,noreferrer')}
+                className="gap-2"
+              >
                 <ExternalLink className="w-4 h-4" />
                 View Pull Request
               </Button>
@@ -277,7 +280,7 @@ export function CreatePRDialog({
               <Button
                 onClick={() => {
                   if (browserUrl) {
-                    window.open(browserUrl, '_blank');
+                    window.open(browserUrl, '_blank', 'noopener,noreferrer');
                   }
                 }}
                 className="gap-2 w-full"
diff --git a/apps/ui/src/components/views/board-view/worktree-panel/components/worktree-actions-dropdown.tsx b/apps/ui/src/components/views/board-view/worktree-panel/components/worktree-actions-dropdown.tsx
index c7d8f26b..a8ae73d9 100644
--- a/apps/ui/src/components/views/board-view/worktree-panel/components/worktree-actions-dropdown.tsx
+++ b/apps/ui/src/components/views/board-view/worktree-panel/components/worktree-actions-dropdown.tsx
@@ -143,8 +143,12 @@ export function WorktreeActionsDropdown({
               <span className="w-2 h-2 rounded-full bg-green-500 animate-pulse" />
               Dev Server Running (:{devServerInfo?.port})
             </DropdownMenuLabel>
-            <DropdownMenuItem onClick={() => onOpenDevServerUrl(worktree)} className="text-xs">
-              <Globe className="w-3.5 h-3.5 mr-2" />
+            <DropdownMenuItem
+              onClick={() => onOpenDevServerUrl(worktree)}
+              className="text-xs"
+              aria-label={`Open dev server on port ${devServerInfo?.port} in browser`}
+            >
+              <Globe className="w-3.5 h-3.5 mr-2" aria-hidden="true" />
               Open in Browser
             </DropdownMenuItem>
             <DropdownMenuItem
@@ -320,7 +324,7 @@ export function WorktreeActionsDropdown({
           <>
             <DropdownMenuItem
               onClick={() => {
-                window.open(worktree.pr!.url, '_blank');
+                window.open(worktree.pr!.url, '_blank', 'noopener,noreferrer');
               }}
               className="text-xs"
             >
diff --git a/apps/ui/src/components/views/board-view/worktree-panel/components/worktree-tab.tsx b/apps/ui/src/components/views/board-view/worktree-panel/components/worktree-tab.tsx
index 3945cf47..5d73060e 100644
--- a/apps/ui/src/components/views/board-view/worktree-panel/components/worktree-tab.tsx
+++ b/apps/ui/src/components/views/board-view/worktree-panel/components/worktree-tab.tsx
@@ -298,20 +298,29 @@ export function WorktreeTab({
       )}
 
       {isDevServerRunning && (
-        <Button
-          variant={isSelected ? 'default' : 'outline'}
-          size="sm"
-          className={cn(
-            'h-7 w-7 p-0 rounded-none border-r-0',
-            isSelected && 'bg-primary text-primary-foreground',
-            !isSelected && 'bg-secondary/50 hover:bg-secondary',
-            'text-green-500'
-          )}
-          onClick={() => onOpenDevServerUrl(worktree)}
-          title={`Open dev server (port ${devServerInfo?.port})`}
-        >
-          <Globe className="w-3 h-3" />
-        </Button>
+        <TooltipProvider>
+          <Tooltip>
+            <TooltipTrigger asChild>
+              <Button
+                variant={isSelected ? 'default' : 'outline'}
+                size="sm"
+                className={cn(
+                  'h-7 w-7 p-0 rounded-none border-r-0',
+                  isSelected && 'bg-primary text-primary-foreground',
+                  !isSelected && 'bg-secondary/50 hover:bg-secondary',
+                  'text-green-500'
+                )}
+                onClick={() => onOpenDevServerUrl(worktree)}
+                aria-label={`Open dev server on port ${devServerInfo?.port} in browser`}
+              >
+                <Globe className="w-3 h-3" aria-hidden="true" />
+              </Button>
+            </TooltipTrigger>
+            <TooltipContent>
+              <p>Open dev server (:{devServerInfo?.port})</p>
+            </TooltipContent>
+          </Tooltip>
+        </TooltipProvider>
       )}
 
       <WorktreeActionsDropdown
diff --git a/apps/ui/src/components/views/board-view/worktree-panel/hooks/use-dev-servers.ts b/apps/ui/src/components/views/board-view/worktree-panel/hooks/use-dev-servers.ts
index 7733a5ff..b3334702 100644
--- a/apps/ui/src/components/views/board-view/worktree-panel/hooks/use-dev-servers.ts
+++ b/apps/ui/src/components/views/board-view/worktree-panel/hooks/use-dev-servers.ts
@@ -118,8 +118,37 @@ export function useDevServers({ projectPath }: UseDevServersOptions) {
   const handleOpenDevServerUrl = useCallback(
     (worktree: WorktreeInfo) => {
       const serverInfo = runningDevServers.get(getWorktreeKey(worktree));
-      if (serverInfo) {
-        window.open(serverInfo.url, '_blank');
+      if (!serverInfo) {
+        logger.warn('No dev server info found for worktree:', getWorktreeKey(worktree));
+        toast.error('Dev server not found', {
+          description: 'The dev server may have stopped. Try starting it again.',
+        });
+        return;
+      }
+
+      try {
+        // Rewrite URL hostname to match the current browser's hostname.
+        // This ensures dev server URLs work when accessing Automaker from
+        // remote machines (e.g., 192.168.x.x or hostname.local instead of localhost).
+        const devServerUrl = new URL(serverInfo.url);
+
+        // Security: Only allow http/https protocols to prevent potential attacks
+        // via data:, javascript:, file:, or other dangerous URL schemes
+        if (devServerUrl.protocol !== 'http:' && devServerUrl.protocol !== 'https:') {
+          logger.error('Invalid dev server URL protocol:', devServerUrl.protocol);
+          toast.error('Invalid dev server URL', {
+            description: 'The server returned an unsupported URL protocol.',
+          });
+          return;
+        }
+
+        devServerUrl.hostname = window.location.hostname;
+        window.open(devServerUrl.toString(), '_blank', 'noopener,noreferrer');
+      } catch (error) {
+        logger.error('Failed to parse dev server URL:', error);
+        toast.error('Failed to open dev server', {
+          description: 'The server URL could not be processed. Please try again.',
+        });
       }
     },
     [runningDevServers, getWorktreeKey]