diff --git a/src/Storage/Device/S3.php b/src/Storage/Device/S3.php
index 429543c6..b910e2be 100644
--- a/src/Storage/Device/S3.php
+++ b/src/Storage/Device/S3.php
@@ -891,8 +891,11 @@ protected function call(string $operation, string $method, string $uri, string $
         $response->code = \curl_getinfo($curl, CURLINFO_HTTP_CODE);
 
         $attempt = 0;
-        while ($attempt < self::$retryAttempts && $response->code >= 500) {
-            usleep(self::$retryDelay * 1000);
+        while (
+            $attempt < self::$retryAttempts &&
+            $this->isTransientError($response->code, $response->body)
+        ) {
+            \usleep(self::$retryDelay * 1000);
             $attempt++;
             $result = \curl_exec($curl);
             $response->code = \curl_getinfo($curl, CURLINFO_HTTP_CODE);
@@ -958,6 +961,39 @@ private function parseAndThrowS3Error(string $errorBody, int $statusCode): void
         throw new Exception($errorBody, $statusCode);
     }
 
+    /**
+     * Determine whether an S3 response indicates a transient rate-limiting error
+     * (e.g. SlowDown, ServiceUnavailable) that should be retried with exponential backoff.
+     *
+     * The XML body is parsed first so that specific S3 error codes are detected regardless
+     * of HTTP status. A 503/429 with a parseable but non-transient error code is NOT retried.
+     * Unparseable 429/503 responses fall back to status-code detection.
+     *
+     * @param  int  $statusCode HTTP response status code
+     * @param  string  $body    Response body
+     * @return bool
+     */
+    protected function isTransientError(int $statusCode, string $body): bool
+    {
+        $trimmed = \ltrim($body);
+        if (\str_starts_with($trimmed, '<?xml') || \str_starts_with($trimmed, '<Error')) {
+            $xml = @\simplexml_load_string($body);
+            if ($xml !== false) {
+                $code = (string) ($xml->Code ?? '');
+                if (\in_array($code, ['SlowDown', 'ServiceUnavailable', 'Throttling', 'RequestThrottled'], true)) {
+                    return true;
+                }
+                // Successfully parsed XML with a non-transient error code — do not retry.
+                if ($code !== '') {
+                    return false;
+                }
+            }
+        }
+
+        // Fall back to HTTP status code for responses that cannot be parsed as XML.
+        return $statusCode === 429 || $statusCode === 503;
+    }
+
     /**
      * Sort compare for meta headers
      *
diff --git a/tests/Storage/Device/S3SlowDownTest.php b/tests/Storage/Device/S3SlowDownTest.php
new file mode 100644
index 00000000..634c5b1f
--- /dev/null
+++ b/tests/Storage/Device/S3SlowDownTest.php
@@ -0,0 +1,71 @@
+<?php
+
+namespace Utopia\Tests\Storage\Device;
+
+use PHPUnit\Framework\TestCase;
+use Utopia\Storage\Device\S3;
+
+/**
+ * Testable S3 subclass that exposes protected helpers.
+ */
+class TestableS3 extends S3
+{
+    public function exposedIsTransientError(int $statusCode, string $body): bool
+    {
+        return $this->isTransientError($statusCode, $body);
+    }
+}
+
+class S3SlowDownTest extends TestCase
+{
+    private TestableS3 $s3;
+
+    protected function setUp(): void
+    {
+        $this->s3 = new TestableS3(
+            root: '/root',
+            accessKey: 'test-key',
+            secretKey: 'test-secret',
+            host: 'https://s3.example.com',
+            region: 'us-east-1',
+        );
+    }
+
+    protected function tearDown(): void
+    {
+        S3::setRetryAttempts(3);
+        S3::setRetryDelay(500);
+    }
+
+    public function testTransientXmlErrorIsRetried(): void
+    {
+        $body = '<?xml version="1.0" encoding="UTF-8"?><Error><Code>SlowDown</Code><Message>Please reduce your request rate.</Message></Error>';
+        $this->assertTrue($this->s3->exposedIsTransientError(503, $body));
+    }
+
+    public function testNonTransientXmlErrorIsNotRetried(): void
+    {
+        $body = '<?xml version="1.0" encoding="UTF-8"?><Error><Code>NoSuchKey</Code><Message>The specified key does not exist.</Message></Error>';
+        $this->assertFalse($this->s3->exposedIsTransientError(404, $body));
+    }
+
+    public function testStatusFallbackIsTransient(): void
+    {
+        $this->assertTrue($this->s3->exposedIsTransientError(429, ''));
+        $this->assertTrue($this->s3->exposedIsTransientError(503, ''));
+    }
+
+    /** XML error code takes precedence over HTTP status — 503 with non-transient XML must not be retried. */
+    public function test503WithNonTransientXmlIsNotRetried(): void
+    {
+        $body = '<?xml version="1.0" encoding="UTF-8"?><Error><Code>InternalError</Code><Message>Internal server error.</Message></Error>';
+        $this->assertFalse($this->s3->exposedIsTransientError(503, $body));
+    }
+
+    public function testDefaultRetrySettings(): void
+    {
+        $prop = fn (string $name) => (new \ReflectionProperty(S3::class, $name))->getValue();
+        $this->assertSame(3, $prop('retryAttempts'));
+        $this->assertSame(500, $prop('retryDelay'));
+    }
+}