diff --git a/pkg/api/instance_handler.go b/pkg/api/instance_handler.go
index df951ecca..7d59cd421 100644
--- a/pkg/api/instance_handler.go
+++ b/pkg/api/instance_handler.go
@@ -71,7 +71,7 @@ func UpdateInstance(instanceName string, instance models.Instance) error {
 		return err
 	}
 
-	log.Infof("Instance %s updated", instance.Name)
+	fmt.Printf("Instance %s updated\n", instance.Name)
 	return nil
 }
 
diff --git a/pkg/utils/helper.go b/pkg/utils/helper.go
index 9255129c7..77c6f2286 100644
--- a/pkg/utils/helper.go
+++ b/pkg/utils/helper.go
@@ -177,10 +177,11 @@ func ValidateRegistryName(rn string) bool {
 	return re.MatchString(rn)
 }
 
-// ValidateURL checks if the URL has valid format, non-empty host, and host is a valid IP or domain.
-// Domain regex: labels must start/end with alphanumeric, can contain hyphens, max 63 chars, TLD min 2 letters.
+// ValidateURL checks that the URL has a valid format and a non-empty host.
+// The host may be an IP address, "localhost", or an RFC 1123-style hostname validated by domainNameRegex.
 func ValidateURL(rawURL string) error {
-	var domainNameRegex = regexp.MustCompile(`^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$`)
+	pattern := `^(?i:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?)(?:\.[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?)*$`
+	domainNameRegex := regexp.MustCompile(pattern)
 
 	parsedURL, err := url.ParseRequestURI(rawURL)
 	if err != nil {
diff --git a/pkg/utils/helper_test.go b/pkg/utils/helper_test.go
index 33c3aba4d..4e4ff8c6c 100644
--- a/pkg/utils/helper_test.go
+++ b/pkg/utils/helper_test.go
@@ -147,6 +147,9 @@ func TestValidateURL(t *testing.T) {
 		{"valid localhost https", "https://localhost", false},
 		{"valid localhost http with port", "http://localhost:8080", false},
 		{"valid localhost https with port", "https://localhost:8443", false},
+		{"valid single-label hostname", "http://harbor", false},
+		{"valid single-label with hyphen", "https://registry-server", false},
+		{"valid single-label with port", "http://harbor:8080", false},
 
 		// invalid URLs
 		{"empty string", "", true},