diff --git a/src/_layouts/default.html b/src/_layouts/default.html
index 1830bc6fd1..2e902d9907 100644
--- a/src/_layouts/default.html
+++ b/src/_layouts/default.html
@@ -23,7 +23,14 @@
 <body>
   <nav class="navbar navbar-dark fixed-top bg-dark flex-md-nowrap p-0 shadow">
     <a class="navbar-brand col-sm-3 col-md-2 mr-0" href="/">{{ site.title }}</a>
-    <!-- <input class="form-control form-control-dark w-100" type="text" placeholder="Search" aria-label="Search"> -->
+    <form class="search-form" action="/search" method="get">
+      <input class="form-control form-control-dark w-100" type="text" placeholder="Search" aria-label="Search" name="q">
+    </form>
+    <ul class="navbar-nav px-3">
+      <li class="nav-item text-nowrap">
+        <a class="nav-link" href="https://github.com/railsdoc/railsdoc.github.io">GitHub</a>
+      </li>
+    </ul>
   </nav>
 
   <div class="container-fluid">
diff --git a/src/_sass/railsdoc.scss b/src/_sass/railsdoc.scss
index 890da27688..eda4180db3 100644
--- a/src/_sass/railsdoc.scss
+++ b/src/_sass/railsdoc.scss
@@ -4,7 +4,6 @@ $red: #cc0000;
 $dark-red: #990000;
 
 // global
-
 a {
   color: $red;
 
@@ -17,6 +16,11 @@ code {
   color: #333;
 }
 
+// Header
+.search-form {
+  width: 100%;
+}
+
 // Sidebar
 .sidebar {
   position: fixed;
diff --git a/src/search.html b/src/search.html
new file mode 100644
index 0000000000..c6b4949abb
--- /dev/null
+++ b/src/search.html
@@ -0,0 +1,17 @@
+---
+title: RDOC_MAIN.rdoc
+layout: default
+---
+
+<script>
+    (function () {
+        var cx = '011796726412992573594:6ifdgquoma4';
+        var gcse = document.createElement('script');
+        gcse.type = 'text/javascript';
+        gcse.async = true;
+        gcse.src = 'https://cse.google.com/cse.js?cx=' + cx;
+        var s = document.getElementsByTagName('script')[0];
+        s.parentNode.insertBefore(gcse, s);
+    })();
+</script>
+<gcse:searchresults-only linktarget="_self"></gcse:searchresults-only>
