diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 7c74231a0..b229996d7 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -13,22 +13,18 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-versions: ['8.1', '8.2']
-        drupal-core: ['10.3.x']
-        phpstan: ['0']
+        # # php-versions: ['8.1', '8.2']
+        # # drupal-core: ['10.3.x']
+        # phpstan: ['0']
         include:
-          # Extra run to test older supported Drupal 10.1.x.
-          - php-versions: '8.1'
-            drupal-core: '10.1.x'
-            phpstan: '0'
           # Extra run to test older supported Drupal 10.2.x.
-          - php-versions: '8.1'
-            drupal-core: '10.2.x'
-            phpstan: '0'
+          # - php-versions: '8.1'
+          #   drupal-core: '10.2.x'
+          #   phpstan: '0'
           # We only need to run PHPStan once on the latest PHP version.
-          - php-versions: '8.3'
-            drupal-core: '10.3.x'
-            phpstan: '1'
+          # - php-versions: '8.3'
+          #   drupal-core: '10.3.x'
+          #   phpstan: '1'
           - php-versions: '8.3'
             drupal-core: '11.0.x'
             phpstan: '1'
diff --git a/graphql.info.yml b/graphql.info.yml
index 90852febe..8b43f0087 100644
--- a/graphql.info.yml
+++ b/graphql.info.yml
@@ -3,6 +3,6 @@ type: module
 description: 'Base module for integrating GraphQL with Drupal.'
 package: GraphQL
 configure: graphql.config_page
-core_version_requirement: ^10.1 || ^11
+core_version_requirement: ^10.2 || ^11
 dependencies:
   - typed_data:typed_data
diff --git a/graphql.services.yml b/graphql.services.yml
index ad0c2c9a7..23c01419f 100644
--- a/graphql.services.yml
+++ b/graphql.services.yml
@@ -184,6 +184,7 @@ services:
       - '@renderer'
       - '@event_dispatcher'
       - '@image.factory'
+      - '@file.validator'
 
   plugin.manager.graphql.persisted_query:
     class: Drupal\graphql\Plugin\PersistedQueryPluginManager
diff --git a/src/GraphQL/Response/Response.php b/src/GraphQL/Response/Response.php
index 20b2c4eff..4467445bc 100644
--- a/src/GraphQL/Response/Response.php
+++ b/src/GraphQL/Response/Response.php
@@ -27,7 +27,7 @@ public function addViolation($message, array $properties = []): void {
   /**
    * {@inheritdoc}
    */
-  public function addViolations(array $messages, array $properties = []): void {
+  public function addViolations($messages, array $properties = []): void {
     foreach ($messages as $message) {
       $this->addViolation($message, $properties);
     }
diff --git a/src/GraphQL/Response/ResponseInterface.php b/src/GraphQL/Response/ResponseInterface.php
index f8f050ab0..f83eda7c7 100644
--- a/src/GraphQL/Response/ResponseInterface.php
+++ b/src/GraphQL/Response/ResponseInterface.php
@@ -12,7 +12,7 @@ interface ResponseInterface {
   /**
    * Adds the violation.
    *
-   * @param string|\Drupal\Core\StringTranslation\TranslatableMarkup $message
+   * @param string|\Drupal\Core\StringTranslation\TranslatableMarkup|\Symfony\Component\Validator\ConstraintViolationListInterface $message
    *   Violation message.
    * @param array $properties
    *   Other properties related to the violation.
@@ -22,12 +22,12 @@ public function addViolation($message, array $properties = []): void;
   /**
    * Adds multiple violations.
    *
-   * @param string[]|\Drupal\Core\StringTranslation\TranslatableMarkup[] $messages
+   * @param string[]|\Drupal\Core\StringTranslation\TranslatableMarkup[]|\Symfony\Component\Validator\ConstraintViolationListInterface $messages
    *   Violation messages.
    * @param array $properties
    *   Other properties related to the violation.
    */
-  public function addViolations(array $messages, array $properties = []): void;
+  public function addViolations(array|ConstraintViolationListInterface $messages, array $properties = []): void;
 
   /**
    * Gets the violations.
diff --git a/src/GraphQL/Utility/FileUpload.php b/src/GraphQL/Utility/FileUpload.php
index 7543ea5c7..1d6a52d2f 100644
--- a/src/GraphQL/Utility/FileUpload.php
+++ b/src/GraphQL/Utility/FileUpload.php
@@ -17,9 +17,11 @@
 use Drupal\Core\Render\RenderContext;
 use Drupal\Core\Render\RendererInterface;
 use Drupal\Core\Session\AccountProxyInterface;
+use Drupal\Core\StringTranslation\ByteSizeMarkup;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\Utility\Token;
 use Drupal\file\FileInterface;
+use Drupal\file\Validation\FileValidatorInterface;
 use Drupal\graphql\GraphQL\Response\FileUploadResponse;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\HttpFoundation\File\UploadedFile;
@@ -111,6 +113,13 @@ class FileUpload {
    */
   protected $imageFactory;
 
+  /**
+   * The file validator service.
+   *
+   * @var \Drupal\file\Validation\FileValidatorInterface
+   */
+  protected FileValidatorInterface $fileValidator;
+
   /**
    * Constructor.
    */
@@ -126,6 +135,7 @@ public function __construct(
     RendererInterface $renderer,
     EventDispatcherInterface $eventDispatcher,
     ImageFactory $image_factory,
+    FileValidatorInterface $file_validator,
   ) {
     /** @var \Drupal\file\FileStorageInterface $file_storage */
     $file_storage = $entityTypeManager->getStorage('file');
@@ -140,6 +150,7 @@ public function __construct(
     $this->renderer = $renderer;
     $this->eventDispatcher = $eventDispatcher;
     $this->imageFactory = $image_factory;
+    $this->fileValidator = $file_validator;
   }
 
   /**
@@ -193,10 +204,7 @@ public function saveFileUpload(UploadedFile $uploaded_file, array $settings): Fi
     switch ($uploaded_file->getError()) {
       case UPLOAD_ERR_INI_SIZE:
       case UPLOAD_ERR_FORM_SIZE:
-        // @todo Drupal 10.1 compatibility, needs to be converted to
-        // ByteSizeMarkup later.
-        // @phpstan-ignore-next-line
-        $maxUploadSize = format_size($this->getMaxUploadSize($settings));
+        $maxUploadSize = ByteSizeMarkup::create($this->getMaxUploadSize($settings));
         $response->addViolation($this->t('The file @file could not be saved because it exceeds @maxsize, the maximum allowed size for uploads.', [
           '@file' => $uploaded_file->getClientOriginalName(),
           '@maxsize' => $maxUploadSize,
@@ -248,8 +256,8 @@ public function saveFileUpload(UploadedFile $uploaded_file, array $settings): Fi
 
     $temp_file_path = $uploaded_file->getRealPath();
 
-    // Drupal 10.2 compatibility: use the deprecated constant for now.
-    // @phpstan-ignore-next-line
+    // Drupal 10.3 compatibility: use the deprecated constant for now.
+    // @phpstan-ignore-next-line as it is deprecated in D12.
     $file_uri = $this->fileSystem->getDestinationFilename($file_uri, FileSystemInterface::EXISTS_RENAME);
 
     // Lock based on the prepared file URI.
@@ -272,11 +280,9 @@ public function saveFileUpload(UploadedFile $uploaded_file, array $settings): Fi
       // before it is saved.
       $file->setSize(@filesize($temp_file_path));
 
-      // Validate against file_validate() first with the temporary path.
-      // @todo Drupal 10.1 compatibility, needs to be converted to file validate
-      // service later.
-      // @phpstan-ignore-next-line
-      $errors = file_validate($file, $validators);
+      // Validate against fileValidator first with the temporary path.
+      /** @var \Symfony\Component\Validator\ConstraintViolationListInterface $errors */
+      $errors = $this->fileValidator->validate($file, $validators);
       $maxResolution = $settings['max_resolution'] ?? 0;
       $minResolution = $settings['min_resolution'] ?? 0;
       if (!empty($maxResolution) || !empty($minResolution)) {
@@ -579,7 +585,7 @@ protected function getUploadLocation(array $settings): string {
   protected function getUploadValidators(array $settings): array {
     $validators = [
       // Add in our check of the file name length.
-      'file_validate_name_length' => [],
+      'FileNameLength' => [],
     ];
 
     // Cap the upload size according to the PHP limit.
@@ -589,11 +595,11 @@ protected function getUploadValidators(array $settings): array {
     }
 
     // There is always a file size limit due to the PHP server limit.
-    $validators['file_validate_size'] = [$max_filesize];
+    $validators['FileSizeLimit'] = ['fileLimit' => $max_filesize];
 
     // Add the extension check if necessary.
     if (!empty($settings['file_extensions'])) {
-      $validators['file_validate_extensions'] = [$settings['file_extensions']];
+      $validators['FileExtension'] = ['extensions' => $settings['file_extensions']];
     }
 
     return $validators;
diff --git a/tests/src/Kernel/AlterableSchemaTest.php b/tests/src/Kernel/AlterableSchemaTest.php
index f9f97d6c8..557249b45 100644
--- a/tests/src/Kernel/AlterableSchemaTest.php
+++ b/tests/src/Kernel/AlterableSchemaTest.php
@@ -156,7 +156,6 @@ protected function mockSchema($id, $schema, array $extensions = []): void {
     $extensions['graphql_alterable_schema_test']->expects(static::any())
       ->method('getBaseDefinition')
       ->willReturn('');
-
     // Different extension definition for different tests.
     switch ($this->getName()) {
       case 'testEmptySchemaExtensionAlteredQueryResultPropertyAdded':
diff --git a/tests/src/Kernel/Framework/UploadFileServiceTest.php b/tests/src/Kernel/Framework/UploadFileServiceTest.php
index 79ddf8c2c..c0307bd6b 100644
--- a/tests/src/Kernel/Framework/UploadFileServiceTest.php
+++ b/tests/src/Kernel/Framework/UploadFileServiceTest.php
@@ -104,7 +104,7 @@ public function testPartialFile(): void {
     ]);
     $violations = $file_upload_response->getViolations();
 
-    $this->assertStringMatchesFormat(
+    $this->assertStringContainsString(
       'The file "test.txt" could not be saved because the upload did not complete.',
       $violations[0]['message']
     );
@@ -140,7 +140,7 @@ public function testSizeValidation(): void {
     $violations = $file_upload_response->getViolations();
 
     // @todo Do we want HTML tags in our violations or not?
-    $this->assertStringMatchesFormat(
+    $this->assertStringContainsString(
       'The file is <em class="placeholder">4 bytes</em> exceeding the maximum file size of <em class="placeholder">1 byte</em>.',
       $violations[0]['message']
     );
@@ -190,7 +190,7 @@ public function testDimensionTooSmallValidation(): void {
     ]);
     $violations = $file_upload_response->getViolations();
 
-    $this->assertStringMatchesFormat(
+    $this->assertStringContainsString(
       'The image is too small. The minimum dimensions are <em class="placeholder">15x15</em> pixels and the image size is <em class="placeholder">10</em>x<em class="placeholder">10</em> pixels.',
       $violations[0]['message']
     );
@@ -228,7 +228,7 @@ public function testExtensionValidation(): void {
     $violations = $file_upload_response->getViolations();
 
     // @todo Do we want HTML tags in our violations or not?
-    $this->assertStringMatchesFormat(
+    $this->assertStringContainsString(
       'Only files with the following extensions are allowed: <em class="placeholder">odt</em>.',
       $violations[0]['message']
     );
@@ -256,6 +256,7 @@ public function testLockReleased(): void {
       \Drupal::service('renderer'),
       \Drupal::service('event_dispatcher'),
       \Drupal::service('image.factory'),
+      \Drupal::service('file.validator'),
     );
 
     // Create a Symfony dummy uploaded file in test mode.
@@ -319,7 +320,7 @@ public function testUnsuccessWithMultipleFileUploads(): void {
 
     // There must be violation regarding forbidden file extension.
     $violations = $file_upload_response->getViolations();
-    $this->assertStringMatchesFormat(
+    $this->assertStringContainsString(
       'Only files with the following extensions are allowed: <em class="placeholder">txt</em>.',
       $violations[0]['message']
     );
diff --git a/tests/src/Kernel/GraphQLTestBase.php b/tests/src/Kernel/GraphQLTestBase.php
index 20425566f..f60b5338d 100644
--- a/tests/src/Kernel/GraphQLTestBase.php
+++ b/tests/src/Kernel/GraphQLTestBase.php
@@ -50,6 +50,7 @@ abstract class GraphQLTestBase extends KernelTestBase {
     'content_translation',
     'entity_reference_test',
     'field',
+    'file',
     'menu_link_content',
     'link',
     'typed_data',