diff --git a/site/src/components/viewer/script.js b/site/src/components/viewer/script.js
index 14ac720..fe7b533 100644
--- a/site/src/components/viewer/script.js
+++ b/site/src/components/viewer/script.js
@@ -16,6 +16,11 @@ export default
         version()
         {
             return this.$store.state.files.currentVersion
+        },
+
+        linesCount()
+        {
+            return (this.$store.state.files.currentVersion.content.match(/\n/g) || []).length + 1
         }
     },
 
diff --git a/site/src/components/viewer/template.html b/site/src/components/viewer/template.html
index ac4718e..4863a04 100644
--- a/site/src/components/viewer/template.html
+++ b/site/src/components/viewer/template.html
@@ -1,3 +1,6 @@
 <div class="viewer" v-if="version">
     <pre v-highlightjs="version.content" contenteditable @keydown="onCodeKeyDown($event)"><code></code></pre>
+    <div class="lines">
+        <div class="line" v-for="i in linesCount">{{ i }}</div>
+    </div>
 </div>
\ No newline at end of file