diff --git a/bin/playwright-server.js b/bin/playwright-server.js
index f9fa1b5..5d55e28 100644
--- a/bin/playwright-server.js
+++ b/bin/playwright-server.js
@@ -121,7 +121,7 @@ class PlaywrightServer extends BaseHandler {
     const info = this.validateResource(this.routes, command.routeId, 'Route');
     const route = info.route || info;
     const registry = CommandRegistry.create({
-      fulfill: () => route.fulfill(command.options),
+      fulfill: () => this.fulfillRoute(route, command.options),
       abort: () => route.abort(command.errorCode),
       redirectNavigationRequest: () => this.redirectNavigationRequest(route, info, command),
       continue: () => this.continueRoute(route, info, command)
@@ -131,6 +131,15 @@ class PlaywrightServer extends BaseHandler {
     this.routes.delete(command.routeId);
   }
 
+  async fulfillRoute(route, options = {}) {
+    const { isBase64, ...fulfillOptions } = options;
+    if (isBase64) {
+      if (typeof fulfillOptions.body !== 'string') throw new Error('route.fulfill isBase64 requires a string body');
+      fulfillOptions.body = Buffer.from(fulfillOptions.body, 'base64');
+    }
+    await route.fulfill(fulfillOptions);
+  }
+
   async redirectNavigationRequest(route, info, command) {
     if (!this.pages.has(info.contextId)) throw new Error('Navigation redirects require a page route');
     this.navigationRedirects.set(info.contextId, command.url);
diff --git a/tests/Functional/Network/RouteTest.php b/tests/Functional/Network/RouteTest.php
index b773aa4..382850e 100644
--- a/tests/Functional/Network/RouteTest.php
+++ b/tests/Functional/Network/RouteTest.php
@@ -45,6 +45,25 @@ public function testCanInterceptAndFulfillRequest(): void
         $this->assertStringContainsString('Mocked response', $result);
     }
 
+    public function testCanFulfillBase64EncodedBinaryBody(): void
+    {
+        $this->goto('/index.html');
+        $expected = [0x77, 0x4F, 0x46, 0x32, 0x00, 0x01, 0x02, 0xFF];
+
+        $this->page->route('**/binary', static function ($route) use ($expected): void {
+            $route->fulfill([
+                'status' => 200,
+                'contentType' => 'application/octet-stream',
+                'body' => base64_encode(pack('C*', ...$expected)),
+                'isBase64' => true,
+            ]);
+        });
+
+        $result = $this->page->evaluate('async () => Array.from(new Uint8Array(await (await fetch("/binary")).arrayBuffer()))');
+
+        $this->assertSame($expected, $result);
+    }
+
     public function testCanInterceptAndAbortRequest(): void
     {
         $this->goto('/network.html');