diff --git a/app/Livewire/Project/Application/General.php b/app/Livewire/Project/Application/General.php
index 7af0a275d..289c8eeb0 100644
--- a/app/Livewire/Project/Application/General.php
+++ b/app/Livewire/Project/Application/General.php
@@ -12,7 +12,6 @@
 use Illuminate\Support\Collection;
 use Livewire\Component;
 use Livewire\Features\SupportEvents\Event;
-use Spatie\Url\Url;
 
 class General extends Component
 {
@@ -142,7 +141,8 @@ protected function rules(): array
         return [
             'name' => ValidationPatterns::nameRules(),
             'description' => ValidationPatterns::descriptionRules(),
-            'fqdn' => 'nullable',
+            'fqdn' => ValidationPatterns::applicationDomainRules(),
+            'parsedServiceDomains.*.domain' => ValidationPatterns::applicationDomainRules(),
             'gitRepository' => 'required',
             'gitBranch' => ['required', 'string', new ValidGitBranch],
             'gitCommitSha' => ['nullable', 'string', 'regex:/^[a-zA-Z0-9][a-zA-Z0-9._\-\/]*$/'],
@@ -771,16 +771,7 @@ public function submit($showToaster = true)
             $oldBaseDirectory = $this->application->base_directory;
 
             // Process FQDN with intermediate variable to avoid Collection/string confusion
-            $this->fqdn = str($this->fqdn)->replaceEnd(',', '')->trim()->toString();
-            $this->fqdn = str($this->fqdn)->replaceStart(',', '')->trim()->toString();
-            $domains = str($this->fqdn)->trim()->explode(',')->map(function ($domain) {
-                $domain = trim($domain);
-                Url::fromString($domain, ['http', 'https']);
-
-                return str($domain)->lower();
-            });
-
-            $this->fqdn = $domains->unique()->implode(',');
+            $this->fqdn = ValidationPatterns::normalizeApplicationDomains($this->fqdn);
             $warning = sslipDomainWarning($this->fqdn);
             if ($warning) {
                 $this->dispatch('warning', __('warning.sslipdomain'));
@@ -863,6 +854,9 @@ public function submit($showToaster = true)
                 }
             }
             if ($this->buildPack === 'dockercompose') {
+                foreach ($this->parsedServiceDomains as $serviceName => $service) {
+                    $this->parsedServiceDomains[$serviceName]['domain'] = ValidationPatterns::normalizeApplicationDomains(data_get($service, 'domain'));
+                }
                 $this->application->docker_compose_domains = json_encode($this->parsedServiceDomains);
                 if ($this->application->isDirty('docker_compose_domains')) {
                     foreach ($this->parsedServiceDomains as $service) {
diff --git a/app/Livewire/Project/Application/Previews.php b/app/Livewire/Project/Application/Previews.php
index 74b2ebce8..338f102b5 100644
--- a/app/Livewire/Project/Application/Previews.php
+++ b/app/Livewire/Project/Application/Previews.php
@@ -6,6 +6,7 @@
 use App\Jobs\DeleteResourceJob;
 use App\Models\Application;
 use App\Models\ApplicationPreview;
+use App\Support\ValidationPatterns;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Illuminate\Support\Collection;
 use Livewire\Component;
@@ -117,12 +118,14 @@ public function save_preview($preview_id)
             });
 
             if ($previewKey !== false && isset($this->previewFqdns[$previewKey])) {
+                $this->validate([
+                    "previewFqdns.{$previewKey}" => ValidationPatterns::applicationDomainRules(),
+                ]);
+
                 $fqdn = $this->previewFqdns[$previewKey];
 
                 if (! empty($fqdn)) {
-                    $fqdn = str($fqdn)->replaceEnd(',', '')->trim();
-                    $fqdn = str($fqdn)->replaceStart(',', '')->trim();
-                    $fqdn = str($fqdn)->trim()->lower();
+                    $fqdn = ValidationPatterns::normalizeApplicationDomains($fqdn);
                     $this->previewFqdns[$previewKey] = $fqdn;
 
                     if (! validateDNSEntry($fqdn, $this->application->destination->server)) {
diff --git a/app/Livewire/Project/Application/PreviewsCompose.php b/app/Livewire/Project/Application/PreviewsCompose.php
index e8da3b45c..48392a742 100644
--- a/app/Livewire/Project/Application/PreviewsCompose.php
+++ b/app/Livewire/Project/Application/PreviewsCompose.php
@@ -3,6 +3,7 @@
 namespace App\Livewire\Project\Application;
 
 use App\Models\ApplicationPreview;
+use App\Support\ValidationPatterns;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Livewire\Component;
 use Spatie\Url\Url;
@@ -33,6 +34,11 @@ public function save()
     {
         try {
             $this->authorize('update', $this->preview->application);
+            $this->validate([
+                'domain' => ValidationPatterns::applicationDomainRules(),
+            ]);
+
+            $this->domain = ValidationPatterns::normalizeApplicationDomains($this->domain);
 
             $docker_compose_domains = data_get($this->preview, 'docker_compose_domains');
             $docker_compose_domains = json_decode($docker_compose_domains, true) ?: [];
@@ -73,9 +79,13 @@ public function generate()
                 $preview_fqdn = str_replace('{{pr_id}}', $this->preview->pull_request_id, $preview_fqdn);
                 $preview_fqdn = str($generated_fqdn)->before('://').'://'.$preview_fqdn;
             } else {
+                foreach (ValidationPatterns::validateApplicationDomains($domain_string) as $error) {
+                    throw new \InvalidArgumentException($error);
+                }
+
                 // Use the existing domain from the main application
                 // Handle multiple domains separated by commas
-                $domain_list = explode(',', $domain_string);
+                $domain_list = ValidationPatterns::applicationDomainList($domain_string);
                 $preview_fqdns = [];
                 $template = $this->preview->application->preview_url_template;
                 $random = new_public_id();
diff --git a/app/Livewire/Project/Service/EditDomain.php b/app/Livewire/Project/Service/EditDomain.php
index 7158b6e40..96fe6a62c 100644
--- a/app/Livewire/Project/Service/EditDomain.php
+++ b/app/Livewire/Project/Service/EditDomain.php
@@ -3,10 +3,10 @@
 namespace App\Livewire\Project\Service;
 
 use App\Models\ServiceApplication;
+use App\Support\ValidationPatterns;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Livewire\Attributes\Validate;
 use Livewire\Component;
-use Spatie\Url\Url;
 
 class EditDomain extends Component
 {
@@ -28,12 +28,15 @@ class EditDomain extends Component
 
     public $requiredPort = null;
 
-    #[Validate(['nullable'])]
+    #[Validate]
     public ?string $fqdn = null;
 
-    protected $rules = [
-        'fqdn' => 'nullable',
-    ];
+    protected function rules(): array
+    {
+        return [
+            'fqdn' => ValidationPatterns::applicationDomainRules(),
+        ];
+    }
 
     public function mount()
     {
@@ -82,15 +85,9 @@ public function submit()
     {
         try {
             $this->authorize('update', $this->application);
-            $this->fqdn = str($this->fqdn)->replaceEnd(',', '')->trim()->toString();
-            $this->fqdn = str($this->fqdn)->replaceStart(',', '')->trim()->toString();
-            $domains = str($this->fqdn)->trim()->explode(',')->map(function ($domain) {
-                $domain = trim($domain);
-                Url::fromString($domain, ['http', 'https']);
+            $this->validate();
 
-                return str($domain)->lower();
-            });
-            $this->fqdn = $domains->unique()->implode(',');
+            $this->fqdn = ValidationPatterns::normalizeApplicationDomains($this->fqdn);
             $warning = sslipDomainWarning($this->fqdn);
             if ($warning) {
                 $this->dispatch('warning', __('warning.sslipdomain'));
diff --git a/app/Livewire/Project/Service/Index.php b/app/Livewire/Project/Service/Index.php
index 12c0edbca..7249c8133 100644
--- a/app/Livewire/Project/Service/Index.php
+++ b/app/Livewire/Project/Service/Index.php
@@ -8,11 +8,11 @@
 use App\Models\Service;
 use App\Models\ServiceApplication;
 use App\Models\ServiceDatabase;
+use App\Support\ValidationPatterns;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Illuminate\Support\Collection;
 use Illuminate\Support\Facades\DB;
 use Livewire\Component;
-use Spatie\Url\Url;
 
 class Index extends Component
 {
@@ -480,15 +480,11 @@ public function submitApplication()
     {
         try {
             $this->authorize('update', $this->serviceApplication);
-            $this->fqdn = str($this->fqdn)->replaceEnd(',', '')->trim()->toString();
-            $this->fqdn = str($this->fqdn)->replaceStart(',', '')->trim()->toString();
-            $domains = str($this->fqdn)->trim()->explode(',')->map(function ($domain) {
-                $domain = trim($domain);
-                Url::fromString($domain, ['http', 'https']);
+            $this->validate([
+                'fqdn' => ValidationPatterns::applicationDomainRules(),
+            ]);
 
-                return str($domain)->lower();
-            });
-            $this->fqdn = $domains->unique()->implode(',');
+            $this->fqdn = ValidationPatterns::normalizeApplicationDomains($this->fqdn);
             $warning = sslipDomainWarning($this->fqdn);
             if ($warning) {
                 $this->dispatch('warning', __('warning.sslipdomain'));
diff --git a/tests/Feature/Livewire/ApplicationGeneralDockerRegistryImageValidationTest.php b/tests/Feature/Livewire/ApplicationGeneralDockerRegistryImageValidationTest.php
index 34c889837..3ed6b8544 100644
--- a/tests/Feature/Livewire/ApplicationGeneralDockerRegistryImageValidationTest.php
+++ b/tests/Feature/Livewire/ApplicationGeneralDockerRegistryImageValidationTest.php
@@ -2,6 +2,40 @@
 
 use App\Livewire\Project\Application\General;
 
+it('uses safe domain validation rules in the application general form', function () {
+    $component = new General;
+    $method = new ReflectionMethod($component, 'rules');
+    $rules = $method->invoke($component);
+
+    $validator = validator([
+        'fqdn' => 'http://$(whoami).example.com',
+    ], [
+        'fqdn' => $rules['fqdn'],
+    ]);
+
+    expect($validator->fails())->toBeTrue()
+        ->and($validator->errors()->has('fqdn'))->toBeTrue();
+});
+
+it('uses safe docker compose service domain validation rules in the application general form', function () {
+    $component = new General;
+    $method = new ReflectionMethod($component, 'rules');
+    $rules = $method->invoke($component);
+
+    $validator = validator([
+        'parsedServiceDomains' => [
+            'app' => [
+                'domain' => 'http://$(whoami).example.com',
+            ],
+        ],
+    ], [
+        'parsedServiceDomains.*.domain' => $rules['parsedServiceDomains.*.domain'],
+    ]);
+
+    expect($validator->fails())->toBeTrue()
+        ->and($validator->errors()->has('parsedServiceDomains.app.domain'))->toBeTrue();
+});
+
 it('uses safe docker registry image validation rules in the application general form', function () {
     $component = new General;
     $method = new ReflectionMethod($component, 'rules');