diff --git a/UPGRADE-7.4.md b/UPGRADE-7.4.md
index d3f628bc16b54..145ecde788957 100644
--- a/UPGRADE-7.4.md
+++ b/UPGRADE-7.4.md
@@ -34,3 +34,14 @@ Security
  * Deprecate callable firewall listeners, extend `AbstractListener` or implement `FirewallListenerInterface` instead
  * Deprecate `AbstractListener::__invoke`
  * Deprecate `LazyFirewallContext::__invoke()`
+ * Add argument `$requestDecision` to `AuthenticatorInterface::supports()`;
+   it should be used to report the reason a request isn't supported. E.g:
+
+   ```php
+   public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
+   {
+       $requestDecision?->addReason('This authenticator does not support any request.');
+
+       return false;
+   }
+   ```
diff --git a/src/Symfony/Bundle/SecurityBundle/Resources/views/Collector/security.html.twig b/src/Symfony/Bundle/SecurityBundle/Resources/views/Collector/security.html.twig
index f2706858e45cf..5ffa1a1b82a43 100644
--- a/src/Symfony/Bundle/SecurityBundle/Resources/views/Collector/security.html.twig
+++ b/src/Symfony/Bundle/SecurityBundle/Resources/views/Collector/security.html.twig
@@ -423,7 +423,9 @@
                                         <div id="authenticator-{{ i }}" class="font-normal">
                                             {% if authenticator.supports is same as(false) %}
                                                 <div class="empty">
-                                                    <p>This authenticator did not support the request.</p>
+                                                    {% for reason in (authenticator.requestDecisionReasons ?? []) is empty ? ['This authenticator did not support the request.'] : authenticator.requestDecisionReasons %}
+                                                        <p>{{ reason }}</p>
+                                                    {% endfor %}
                                                 </div>
                                             {% elseif authenticator.authenticated is null %}
                                                 <div class="empty">
diff --git a/src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/Compiler/RegisterEntryPointsPassTest.php b/src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/Compiler/RegisterEntryPointsPassTest.php
index d2fb348676bc7..51003aae1797b 100644
--- a/src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/Compiler/RegisterEntryPointsPassTest.php
+++ b/src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/Compiler/RegisterEntryPointsPassTest.php
@@ -28,6 +28,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;
 use Symfony\Component\Security\Http\Firewall\ExceptionListener;
+use Symfony\Component\Security\Http\RequestDecision;
 
 class RegisterEntryPointsPassTest extends TestCase
 {
@@ -71,7 +72,7 @@ public function testProcessResolvesChildDefinitionsClass()
 
 class CustomAuthenticator extends AbstractAuthenticator implements AuthenticationEntryPointInterface
 {
-    public function supports(Request $request): ?bool
+    public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
     {
         return false;
     }
diff --git a/src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/SecurityExtensionTest.php b/src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/SecurityExtensionTest.php
index 4999fff7347db..c548865c92f47 100644
--- a/src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/SecurityExtensionTest.php
+++ b/src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/SecurityExtensionTest.php
@@ -39,6 +39,7 @@
 use Symfony\Component\Security\Http\Authenticator\AuthenticatorInterface;
 use Symfony\Component\Security\Http\Authenticator\HttpBasicAuthenticator;
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
+use Symfony\Component\Security\Http\RequestDecision;
 
 class SecurityExtensionTest extends TestCase
 {
@@ -968,7 +969,7 @@ protected function getContainer()
 
 class TestAuthenticator implements AuthenticatorInterface
 {
-    public function supports(Request $request): ?bool
+    public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
     {
     }
 
diff --git a/src/Symfony/Bundle/SecurityBundle/Tests/Functional/Bundle/AuthenticatorBundle/ApiAuthenticator.php b/src/Symfony/Bundle/SecurityBundle/Tests/Functional/Bundle/AuthenticatorBundle/ApiAuthenticator.php
index 359e61a2b36e4..0690e59abf536 100644
--- a/src/Symfony/Bundle/SecurityBundle/Tests/Functional/Bundle/AuthenticatorBundle/ApiAuthenticator.php
+++ b/src/Symfony/Bundle/SecurityBundle/Tests/Functional/Bundle/AuthenticatorBundle/ApiAuthenticator.php
@@ -22,6 +22,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Badge\UserBadge;
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\Authenticator\Passport\SelfValidatingPassport;
+use Symfony\Component\Security\Http\RequestDecision;
 
 class ApiAuthenticator extends AbstractAuthenticator
 {
@@ -32,7 +33,7 @@ public function __construct(bool $selfLoadingUser = false)
         $this->selfLoadingUser = $selfLoadingUser;
     }
 
-    public function supports(Request $request): ?bool
+    public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
     {
         return $request->headers->has('X-USER-EMAIL');
     }
diff --git a/src/Symfony/Component/Ldap/Security/LdapAuthenticator.php b/src/Symfony/Component/Ldap/Security/LdapAuthenticator.php
index bb98d210af557..e55999e5c7bc6 100644
--- a/src/Symfony/Component/Ldap/Security/LdapAuthenticator.php
+++ b/src/Symfony/Component/Ldap/Security/LdapAuthenticator.php
@@ -20,6 +20,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;
 use Symfony\Component\Security\Http\EntryPoint\Exception\NotAnEntryPointException;
+use Symfony\Component\Security\Http\RequestDecision;
 
 /**
  * This class decorates internal authenticators to add the LDAP integration.
@@ -44,9 +45,9 @@ public function __construct(
     ) {
     }
 
-    public function supports(Request $request): ?bool
+    public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
     {
-        return $this->authenticator->supports($request);
+        return $this->authenticator->supports($request, $requestDecision);
     }
 
     public function authenticate(Request $request): Passport
diff --git a/src/Symfony/Component/Ldap/Tests/Security/CheckLdapCredentialsListenerTest.php b/src/Symfony/Component/Ldap/Tests/Security/CheckLdapCredentialsListenerTest.php
index 6e69ffe599e75..d4e89697e1390 100644
--- a/src/Symfony/Component/Ldap/Tests/Security/CheckLdapCredentialsListenerTest.php
+++ b/src/Symfony/Component/Ldap/Tests/Security/CheckLdapCredentialsListenerTest.php
@@ -33,6 +33,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\Authenticator\Passport\SelfValidatingPassport;
 use Symfony\Component\Security\Http\Event\CheckPassportEvent;
+use Symfony\Component\Security\Http\RequestDecision;
 use Symfony\Contracts\Service\ServiceLocatorTrait;
 
 class CheckLdapCredentialsListenerTest extends TestCase
@@ -206,7 +207,7 @@ private function createListener()
 if (interface_exists(AuthenticatorInterface::class)) {
     class TestAuthenticator implements AuthenticatorInterface
     {
-        public function supports(Request $request): ?bool
+        public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
         {
         }
 
diff --git a/src/Symfony/Component/Security/Http/Authenticator/AbstractLoginFormAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/AbstractLoginFormAuthenticator.php
index 21835bd32166c..62e679cdd1745 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/AbstractLoginFormAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/AbstractLoginFormAuthenticator.php
@@ -16,6 +16,7 @@
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Security\Core\Exception\AuthenticationException;
 use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;
+use Symfony\Component\Security\Http\RequestDecision;
 use Symfony\Component\Security\Http\SecurityRequestAttributes;
 
 /**
@@ -36,10 +37,26 @@ abstract protected function getLoginUrl(Request $request): string;
      *
      * This default implementation handles all POST requests to the
      * login path (@see getLoginUrl()).
+     *
+     * @param RequestDecision|null $requestDecision
      */
-    public function supports(Request $request): bool
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): bool
     {
-        return $request->isMethod('POST') && $this->getLoginUrl($request) === $request->getBaseUrl().$request->getPathInfo();
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : null;
+
+        if (!$request->isMethod('POST')) {
+            $requestDecision?->addReason('Request is not a POST.');
+
+            return false;
+        }
+
+        if ($this->getLoginUrl($request) !== $request->getBaseUrl().$request->getPathInfo()) {
+            $requestDecision?->addReason('Request does not match the login URL.');
+
+            return false;
+        }
+
+        return true;
     }
 
     /**
diff --git a/src/Symfony/Component/Security/Http/Authenticator/AbstractPreAuthenticatedAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/AbstractPreAuthenticatedAuthenticator.php
index 5017e99162717..2b96e6aa35870 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/AbstractPreAuthenticatedAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/AbstractPreAuthenticatedAuthenticator.php
@@ -24,6 +24,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Badge\UserBadge;
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\Authenticator\Passport\SelfValidatingPassport;
+use Symfony\Component\Security\Http\RequestDecision;
 
 /**
  * The base authenticator for authenticators to use pre-authenticated
@@ -52,20 +53,27 @@ public function __construct(
      */
     abstract protected function extractUsername(Request $request): ?string;
 
-    public function supports(Request $request): ?bool
+    /**
+     * @param RequestDecision|null $requestDecision
+     */
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): ?bool
     {
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : null;
+
         try {
             $username = $this->extractUsername($request);
         } catch (BadCredentialsException $e) {
             $this->clearToken($e);
 
             $this->logger?->debug('Skipping pre-authenticated authenticator as a BadCredentialsException is thrown.', ['exception' => $e, 'authenticator' => static::class]);
+            $requestDecision?->addReason('Could not find the username in the request.');
 
             return false;
         }
 
         if (null === $username) {
             $this->logger?->debug('Skipping pre-authenticated authenticator no username could be extracted.', ['authenticator' => static::class]);
+            $requestDecision?->addReason('Username found in the request was empty.');
 
             return false;
         }
@@ -75,6 +83,7 @@ public function supports(Request $request): ?bool
 
         if ($token instanceof PreAuthenticatedToken && $this->firewallName === $token->getFirewallName() && $token->getUserIdentifier() === $username) {
             $this->logger?->debug('Skipping pre-authenticated authenticator as the user already has an existing session.', ['authenticator' => static::class]);
+            $requestDecision?->addReason('A token already exists for the user in the session.');
 
             return false;
         }
diff --git a/src/Symfony/Component/Security/Http/Authenticator/AccessTokenAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/AccessTokenAuthenticator.php
index 75d69ed6437e7..e2a1e33d46130 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/AccessTokenAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/AccessTokenAuthenticator.php
@@ -24,6 +24,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\Authenticator\Passport\SelfValidatingPassport;
 use Symfony\Component\Security\Http\Authenticator\Token\PostAuthenticationToken;
+use Symfony\Component\Security\Http\RequestDecision;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
@@ -46,9 +47,20 @@ public function __construct(
     ) {
     }
 
-    public function supports(Request $request): ?bool
+    /**
+     * @param RequestDecision|null $requestDecision
+     */
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): ?bool
     {
-        return null === $this->accessTokenExtractor->extractAccessToken($request) ? false : null;
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : null;
+
+        if (null === $this->accessTokenExtractor->extractAccessToken($request)) {
+            $requestDecision?->addReason(sprintf('No token was found in the request by the %s.', $this->accessTokenExtractor::class));
+
+            return false;
+        }
+
+        return null;
     }
 
     public function authenticate(Request $request): Passport
diff --git a/src/Symfony/Component/Security/Http/Authenticator/AuthenticatorInterface.php b/src/Symfony/Component/Security/Http/Authenticator/AuthenticatorInterface.php
index 124e0bf94885d..487e04640f395 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/AuthenticatorInterface.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/AuthenticatorInterface.php
@@ -16,6 +16,7 @@
 use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
 use Symfony\Component\Security\Core\Exception\AuthenticationException;
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
+use Symfony\Component\Security\Http\RequestDecision;
 
 /**
  * The interface for all authenticators.
@@ -32,8 +33,10 @@ interface AuthenticatorInterface
      * If this returns true, authenticate() will be called. If false, the authenticator will be skipped.
      *
      * Returning null means authenticate() can be called lazily when accessing the token storage.
+     *
+     * @param RequestDecision|null $requestDecision
      */
-    public function supports(Request $request): ?bool;
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): ?bool;
 
     /**
      * Create a passport for the current request.
diff --git a/src/Symfony/Component/Security/Http/Authenticator/Debug/TraceableAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/Debug/TraceableAuthenticator.php
index a98c2bc6564f8..bd32cb16ce202 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/Debug/TraceableAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/Debug/TraceableAuthenticator.php
@@ -21,6 +21,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;
 use Symfony\Component\Security\Http\EntryPoint\Exception\NotAnEntryPointException;
+use Symfony\Component\Security\Http\RequestDecision;
 use Symfony\Component\VarDumper\Caster\ClassStub;
 
 /**
@@ -31,6 +32,7 @@
 final class TraceableAuthenticator implements AuthenticatorInterface, InteractiveAuthenticatorInterface, AuthenticationEntryPointInterface
 {
     private ?bool $supports = false;
+    private array $requestDecisionReasons = [];
     private ?Passport $passport = null;
     private ?float $duration = null;
     private ClassStub|string $stub;
@@ -45,6 +47,7 @@ public function getInfo(): array
     {
         return [
             'supports' => $this->supports,
+            'requestDecisionReasons' => $this->requestDecisionReasons,
             'passport' => $this->passport,
             'duration' => $this->duration,
             'stub' => $this->stub ??= class_exists(ClassStub::class) ? new ClassStub($this->authenticator::class) : $this->authenticator::class,
@@ -62,9 +65,24 @@ static function (BadgeInterface $badge): array {
         ];
     }
 
-    public function supports(Request $request): ?bool
+    /**
+     * @param RequestDecision|null $requestDecision
+     */
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): ?bool
     {
-        return $this->supports = $this->authenticator->supports($request);
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : new RequestDecision();
+
+        $this->supports = $this->authenticator->supports($request, $requestDecision);
+        $this->requestDecisionReasons = $requestDecision->reasons;
+
+        if ($this->supports === false) {
+            $requestDecision->isSupported = false;
+        } else {
+            $requestDecision->isSupported = true;
+            $requestDecision->isLazy = null === $this->supports;
+        }
+
+        return $this->supports;
     }
 
     public function authenticate(Request $request): Passport
diff --git a/src/Symfony/Component/Security/Http/Authenticator/FormLoginAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/FormLoginAuthenticator.php
index d8da062e5fafc..c05f466c3a464 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/FormLoginAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/FormLoginAuthenticator.php
@@ -31,6 +31,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\HttpUtils;
 use Symfony\Component\Security\Http\ParameterBagUtils;
+use Symfony\Component\Security\Http\RequestDecision;
 use Symfony\Component\Security\Http\SecurityRequestAttributes;
 
 /**
@@ -68,11 +69,32 @@ protected function getLoginUrl(Request $request): string
         return $this->httpUtils->generateUri($request, $this->options['login_path']);
     }
 
-    public function supports(Request $request): bool
+    /**
+     * @param RequestDecision|null $requestDecision
+     */
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): bool
     {
-        return ($this->options['post_only'] ? $request->isMethod('POST') : true)
-            && $this->httpUtils->checkRequestPath($request, $this->options['check_path'])
-            && ($this->options['form_only'] ? 'form' === $request->getContentTypeFormat() : true);
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : null;
+
+        if ($this->options['post_only'] && !$request->isMethod('POST')) {
+            $requestDecision?->addReason('Request is not a POST while "post_only" is set.');
+
+            return false;
+        }
+
+        if (!$this->httpUtils->checkRequestPath($request, $this->options['check_path'])) {
+            $requestDecision?->addReason('Request does not match the "check_path".');
+
+            return false;
+        }
+
+        if ($this->options['form_only'] && 'form' !== $request->getContentTypeFormat()) {
+            $requestDecision?->addReason('Request is not a form submission while "form_only" is set.');
+
+            return false;
+        }
+
+        return true;
     }
 
     public function authenticate(Request $request): Passport
diff --git a/src/Symfony/Component/Security/Http/Authenticator/HttpBasicAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/HttpBasicAuthenticator.php
index d76c2be9270cc..a3637a8a0b8f5 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/HttpBasicAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/HttpBasicAuthenticator.php
@@ -24,6 +24,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Credentials\PasswordCredentials;
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;
+use Symfony\Component\Security\Http\RequestDecision;
 
 /**
  * @author Wouter de Jong <wouter@wouterj.nl>
@@ -49,9 +50,20 @@ public function start(Request $request, ?AuthenticationException $authException
         return $response;
     }
 
-    public function supports(Request $request): ?bool
+    /**
+     * @param RequestDecision|null $requestDecision
+     */
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): ?bool
     {
-        return $request->headers->has('PHP_AUTH_USER');
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : null;
+
+        if (!$request->headers->has('PHP_AUTH_USER')) {
+            $requestDecision?->addReason('Request has no basic authentication header.');
+
+            return false;
+        }
+
+        return true;
     }
 
     public function authenticate(Request $request): Passport
diff --git a/src/Symfony/Component/Security/Http/Authenticator/JsonLoginAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/JsonLoginAuthenticator.php
index b2cd7b42f5465..736c7473a5822 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/JsonLoginAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/JsonLoginAuthenticator.php
@@ -31,6 +31,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Credentials\PasswordCredentials;
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\HttpUtils;
+use Symfony\Component\Security\Http\RequestDecision;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
@@ -60,16 +61,25 @@ public function __construct(
         $this->propertyAccessor = $propertyAccessor ?: PropertyAccess::createPropertyAccessor();
     }
 
-    public function supports(Request $request): ?bool
+    /**
+     * @param RequestDecision|null $requestDecision
+     */
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): ?bool
     {
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : null;
+
         if (
             !str_contains($request->getRequestFormat() ?? '', 'json')
             && !str_contains($request->getContentTypeFormat() ?? '', 'json')
         ) {
+            $requestDecision?->addReason('Request format is not JSON.');
+
             return false;
         }
 
         if (isset($this->options['check_path']) && !$this->httpUtils->checkRequestPath($request, $this->options['check_path'])) {
+            $requestDecision?->addReason('Request does not match the "check_path".');
+
             return false;
         }
 
diff --git a/src/Symfony/Component/Security/Http/Authenticator/LoginLinkAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/LoginLinkAuthenticator.php
index 1547b6e8464f9..67fc5cc1f0450 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/LoginLinkAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/LoginLinkAuthenticator.php
@@ -25,6 +25,7 @@
 use Symfony\Component\Security\Http\LoginLink\Exception\InvalidLoginLinkAuthenticationException;
 use Symfony\Component\Security\Http\LoginLink\Exception\InvalidLoginLinkExceptionInterface;
 use Symfony\Component\Security\Http\LoginLink\LoginLinkHandlerInterface;
+use Symfony\Component\Security\Http\RequestDecision;
 
 /**
  * @author Ryan Weaver <ryan@symfonycasts.com>
@@ -43,10 +44,26 @@ public function __construct(
         $this->options = $options + ['check_post_only' => false];
     }
 
-    public function supports(Request $request): ?bool
+    /**
+     * @param RequestDecision|null $requestDecision
+     */
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): ?bool
     {
-        return ($this->options['check_post_only'] ? $request->isMethod('POST') : true)
-            && $this->httpUtils->checkRequestPath($request, $this->options['check_route']);
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : null;
+
+        if ($this->options['check_post_only'] && !$request->isMethod('POST')) {
+            $requestDecision?->addReason('Request is not a POST while "check_post_only" is set.');
+
+            return false;
+        }
+
+        if (!$this->httpUtils->checkRequestPath($request, $this->options['check_route'])) {
+            $requestDecision?->addReason('Request does not match the "check_route".');
+
+            return false;
+        }
+
+        return true;
     }
 
     public function authenticate(Request $request): Passport
diff --git a/src/Symfony/Component/Security/Http/Authenticator/RememberMeAuthenticator.php b/src/Symfony/Component/Security/Http/Authenticator/RememberMeAuthenticator.php
index c695be084861b..dd640c82e4cea 100644
--- a/src/Symfony/Component/Security/Http/Authenticator/RememberMeAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Authenticator/RememberMeAuthenticator.php
@@ -27,6 +27,7 @@
 use Symfony\Component\Security\Http\RememberMe\RememberMeDetails;
 use Symfony\Component\Security\Http\RememberMe\RememberMeHandlerInterface;
 use Symfony\Component\Security\Http\RememberMe\ResponseListener;
+use Symfony\Component\Security\Http\RequestDecision;
 
 /**
  * The RememberMe *Authenticator* performs remember me authentication.
@@ -73,18 +74,35 @@ public function __construct(
         $this->logger = $logger;
     }
 
-    public function supports(Request $request): ?bool
+    /**
+     * @param RequestDecision|null $requestDecision
+     */
+    public function supports(Request $request, /* ?RequestDecision $requestDecision = null */): ?bool
     {
+        $requestDecision = 2 <= \func_num_args() ? func_get_arg(1) : null;
+
         // do not overwrite already stored tokens (i.e. from the session)
         if (null !== $this->tokenStorage->getToken()) {
+            $requestDecision?->addReason('A token already exists in the session.');
+
             return false;
         }
 
         if (($cookie = $request->attributes->get(ResponseListener::COOKIE_ATTR_NAME)) && null === $cookie->getValue()) {
+            $requestDecision?->addReason('Cookie is cleared.');
+
             return false;
         }
 
-        if (!$request->cookies->has($this->cookieName) || !\is_scalar($request->cookies->all()[$this->cookieName] ?: null)) {
+        if (!$request->cookies->has($this->cookieName)) {
+            $requestDecision?->addReason(sprintf('Request does not have a "%s" cookie.', $this->cookieName));
+
+            return false;
+        }
+
+        if (!\is_scalar($request->cookies->all()[$this->cookieName] ?: null)) {
+            $requestDecision?->addReason(sprintf('Request does not have a "%s" cookie.', $this->cookieName));
+
             return false;
         }
 
diff --git a/src/Symfony/Component/Security/Http/CHANGELOG.md b/src/Symfony/Component/Security/Http/CHANGELOG.md
index 6c485dc6e5450..beb24ea2eb411 100644
--- a/src/Symfony/Component/Security/Http/CHANGELOG.md
+++ b/src/Symfony/Component/Security/Http/CHANGELOG.md
@@ -6,6 +6,7 @@ CHANGELOG
 
  * Deprecate callable firewall listeners, extend `AbstractListener` or implement `FirewallListenerInterface` instead
  * Deprecate `AbstractListener::__invoke`
+ * Add ability for authenticators to explain why they didn't support a request
 
 7.3
 ---
diff --git a/src/Symfony/Component/Security/Http/RequestDecision.php b/src/Symfony/Component/Security/Http/RequestDecision.php
new file mode 100644
index 0000000000000..bae22e28fbe9b
--- /dev/null
+++ b/src/Symfony/Component/Security/Http/RequestDecision.php
@@ -0,0 +1,26 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Security\Http;
+
+class RequestDecision
+{
+    public bool $isSupported;
+    public ?bool $isLazy = null;
+
+    /** @var list<string> */
+    public array $reasons = [];
+
+    public function addReason(string $reason): void
+    {
+        $this->reasons[] = $reason;
+    }
+}
diff --git a/src/Symfony/Component/Security/Http/Tests/Authenticator/AbstractAuthenticatorTest.php b/src/Symfony/Component/Security/Http/Tests/Authenticator/AbstractAuthenticatorTest.php
index 77ca011f66ce0..d15bfe7a8e485 100644
--- a/src/Symfony/Component/Security/Http/Tests/Authenticator/AbstractAuthenticatorTest.php
+++ b/src/Symfony/Component/Security/Http/Tests/Authenticator/AbstractAuthenticatorTest.php
@@ -22,6 +22,7 @@
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\Authenticator\Passport\SelfValidatingPassport;
 use Symfony\Component\Security\Http\Authenticator\Token\PostAuthenticationToken;
+use Symfony\Component\Security\Http\RequestDecision;
 
 class AbstractAuthenticatorTest extends TestCase
 {
@@ -42,7 +43,7 @@ public function createToken(Passport $passport, string $firewallName): TokenInte
         return parent::createToken($passport, $firewallName);
     }
 
-    public function supports(Request $request): ?bool
+    public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
     {
         return null;
     }
diff --git a/src/Symfony/Component/Security/Http/Tests/Fixtures/DummyAuthenticator.php b/src/Symfony/Component/Security/Http/Tests/Fixtures/DummyAuthenticator.php
index 6e9b6174f1dca..74ea133dcea95 100644
--- a/src/Symfony/Component/Security/Http/Tests/Fixtures/DummyAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Tests/Fixtures/DummyAuthenticator.php
@@ -18,13 +18,14 @@
 use Symfony\Component\Security\Http\Authenticator\AuthenticatorInterface;
 use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
 use Symfony\Component\Security\Http\Authenticator\Passport\PassportInterface;
+use Symfony\Component\Security\Http\RequestDecision;
 
 /**
  * @author Alexandre Daubois <alex.daubois@gmail.com>
  */
 class DummyAuthenticator implements AuthenticatorInterface
 {
-    public function supports(Request $request): ?bool
+    public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
     {
         return null;
     }
diff --git a/src/Symfony/Component/Security/Http/Tests/Fixtures/DummySupportsAuthenticator.php b/src/Symfony/Component/Security/Http/Tests/Fixtures/DummySupportsAuthenticator.php
index 8e7d394a7499a..dae12f10378f0 100644
--- a/src/Symfony/Component/Security/Http/Tests/Fixtures/DummySupportsAuthenticator.php
+++ b/src/Symfony/Component/Security/Http/Tests/Fixtures/DummySupportsAuthenticator.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\Security\Http\Tests\Fixtures;
 
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\Security\Http\RequestDecision;
 
 class DummySupportsAuthenticator extends DummyAuthenticator
 {
@@ -22,7 +23,7 @@ public function __construct(?bool $supports)
         $this->supports = $supports;
     }
 
-    public function supports(Request $request): ?bool
+    public function supports(Request $request, ?RequestDecision $requestDecision = null): ?bool
     {
         return $this->supports;
     }