diff --git a/src/Form/Control/Callbacks/EmailValidateCallback.php b/src/Form/Control/Callbacks/EmailValidateCallback.php
new file mode 100644
index 0000000..8e4c522
--- /dev/null
+++ b/src/Form/Control/Callbacks/EmailValidateCallback.php
@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * Copyright (C) 2024 SYSTOPIA GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace Drupal\json_forms\Form\Control\Callbacks;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Element\Email;
+
+final class EmailValidateCallback {
+
+  /**
+   * @param array<int|string, mixed> $element
+   * @param \Drupal\Core\Form\FormStateInterface $formState
+   * @param array<int|string, mixed> $completeForm
+   */
+  public static function validate(array &$element, FormStateInterface $formState, array $completeForm): void {
+    // @phpstan-ignore argument.type
+    $value = $formState->getValue($element['#parents']);
+
+    // Prevent Email::validateEmail() from setting an empty string when the
+    // current value is NULL and allowed to be NULL.
+    if (NULL !== $value || TRUE !== $element['#_nullable']) {
+      Email::validateEmail($element, $formState, $completeForm);
+    }
+  }
+
+}
diff --git a/src/Form/Control/Callbacks/StringValueCallback.php b/src/Form/Control/Callbacks/StringValueCallback.php
new file mode 100644
index 0000000..e3ad6c1
--- /dev/null
+++ b/src/Form/Control/Callbacks/StringValueCallback.php
@@ -0,0 +1,59 @@
+<?php
+
+/*
+ * Copyright (C) 2022 SYSTOPIA GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace Drupal\json_forms\Form\Control\Callbacks;
+
+use Drupal\Core\Form\FormStateInterface;
+
+final class StringValueCallback {
+
+  /**
+   * @param array<int|string, mixed> $element
+   * @param mixed $input
+   * @param \Drupal\Core\Form\FormStateInterface $formState
+   *
+   * @return mixed
+   */
+  public static function convert(array $element, $input, FormStateInterface $formState) {
+    $value = $input;
+    if (FALSE === $value) {
+      $value = $element['#default_value'] ?? '';
+    }
+
+    if ('' === $value) {
+      if (TRUE === $element['#_nullable']) {
+        $value = NULL;
+      }
+    }
+
+    if (NULL === $value) {
+      // Prevent empty string as value. Drupal sets an empty string in this
+      // case if no value is set in the form state.
+      $formState->setValueForElement($element, NULL);
+    }
+    elseif ('textfield' === $element['#type'] && is_string($value)) {
+      $value = str_replace(["\r", "\n"], '', $value);
+    }
+
+    return $value;
+  }
+
+}
diff --git a/src/Form/Control/Callbacks/UrlValidateCallback.php b/src/Form/Control/Callbacks/UrlValidateCallback.php
new file mode 100644
index 0000000..15095a5
--- /dev/null
+++ b/src/Form/Control/Callbacks/UrlValidateCallback.php
@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * Copyright (C) 2024 SYSTOPIA GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace Drupal\json_forms\Form\Control\Callbacks;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Element\Url;
+
+final class UrlValidateCallback {
+
+  /**
+   * @param array<int|string, mixed> $element
+   * @param \Drupal\Core\Form\FormStateInterface $formState
+   * @param array<int|string, mixed> $completeForm
+   */
+  public static function validate(array &$element, FormStateInterface $formState, array $completeForm): void {
+    // @phpstan-ignore argument.type
+    $value = $formState->getValue($element['#parents']);
+
+    // Prevent Url::validateUrl() from setting an empty string when the current
+    // value is NULL and allowed to be NULL.
+    if (NULL !== $value || TRUE !== $element['#_nullable']) {
+      Url::validateUrl($element, $formState, $completeForm);
+    }
+  }
+
+}
diff --git a/src/Form/Control/EmailArrayFactory.php b/src/Form/Control/EmailArrayFactory.php
index c8e6821..a05bd24 100644
--- a/src/Form/Control/EmailArrayFactory.php
+++ b/src/Form/Control/EmailArrayFactory.php
@@ -22,6 +22,7 @@
 namespace Drupal\json_forms\Form\Control;
 
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\json_forms\Form\Control\Callbacks\EmailValidateCallback;
 use Drupal\json_forms\Form\FormArrayFactoryInterface;
 use Drupal\json_forms\JsonForms\Definition\Control\ControlDefinition;
 use Drupal\json_forms\JsonForms\Definition\DefinitionInterface;
@@ -42,6 +43,7 @@ public function createFormArray(
   ): array {
     return [
       '#type' => 'email',
+      '#element_validate' => [EmailValidateCallback::class . '::validate'],
     ] + parent::createFormArray($definition, $formState, $formArrayFactory);
   }
 
diff --git a/src/Form/Control/StringArrayFactory.php b/src/Form/Control/StringArrayFactory.php
index a2d9d38..506e9b4 100644
--- a/src/Form/Control/StringArrayFactory.php
+++ b/src/Form/Control/StringArrayFactory.php
@@ -24,6 +24,7 @@
 use Assert\Assertion;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\json_forms\Form\AbstractConcreteFormArrayFactory;
+use Drupal\json_forms\Form\Control\Callbacks\StringValueCallback;
 use Drupal\json_forms\Form\Control\Util\BasicFormPropertiesFactory;
 use Drupal\json_forms\Form\FormArrayFactoryInterface;
 use Drupal\json_forms\JsonForms\Definition\Control\ControlDefinition;
@@ -47,6 +48,7 @@ public function createFormArray(
 
     $form = [
       '#type' => TRUE === $definition->getOptionsValue('multi', FALSE) ? 'textarea' : 'textfield',
+      '#value_callback' => StringValueCallback::class . '::convert',
     ] + BasicFormPropertiesFactory::createFieldProperties($definition, $formState);
 
     if (NULL !== $definition->getMaxLength()) {
diff --git a/src/Form/Control/UrlArrayFactory.php b/src/Form/Control/UrlArrayFactory.php
index 58f2f38..8df48ec 100644
--- a/src/Form/Control/UrlArrayFactory.php
+++ b/src/Form/Control/UrlArrayFactory.php
@@ -22,6 +22,7 @@
 namespace Drupal\json_forms\Form\Control;
 
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\json_forms\Form\Control\Callbacks\UrlValidateCallback;
 use Drupal\json_forms\Form\FormArrayFactoryInterface;
 use Drupal\json_forms\JsonForms\Definition\Control\ControlDefinition;
 use Drupal\json_forms\JsonForms\Definition\DefinitionInterface;
@@ -42,6 +43,7 @@ public function createFormArray(
   ): array {
     return [
       '#type' => 'url',
+      '#element_validate' => [UrlValidateCallback::class . '::validate'],
     ] + parent::createFormArray($definition, $formState, $formArrayFactory);
   }
 
diff --git a/src/Form/Control/Util/BasicFormPropertiesFactory.php b/src/Form/Control/Util/BasicFormPropertiesFactory.php
index 344774b..bf2f0b3 100644
--- a/src/Form/Control/Util/BasicFormPropertiesFactory.php
+++ b/src/Form/Control/Util/BasicFormPropertiesFactory.php
@@ -71,6 +71,7 @@ public static function createFieldProperties(ControlDefinition $definition, Form
       '#disabled' => $definition->isReadOnly(),
       '#required' => $definition->isRequired(),
       '#limit_validation_errors' => [],
+      '#_nullable' => $definition->isNullable(),
     ];
 
     if ((!$formState->isCached() || $definition->isReadOnly())
diff --git a/src/JsonForms/Definition/Control/ControlDefinition.php b/src/JsonForms/Definition/Control/ControlDefinition.php
index 44f9e8f..2ab6331 100644
--- a/src/JsonForms/Definition/Control/ControlDefinition.php
+++ b/src/JsonForms/Definition/Control/ControlDefinition.php
@@ -308,6 +308,10 @@ public function getType(): string {
     return $this->propertySchema->type;
   }
 
+  public function isNullable(): bool {
+    return in_array('null', (array) $this->propertySchema->type, TRUE);
+  }
+
   public function isReadOnly(): bool {
     return $this->controlSchema->options->readonly ?? $this->propertySchema->readOnly
       ?? (property_exists($this->propertySchema, '$calculate') || $this->parentUiReadonly);