diff --git a/gulpfile.ts b/gulpfile.ts
index 55452fe7f0..87c3a23a01 100644
--- a/gulpfile.ts
+++ b/gulpfile.ts
@@ -18,6 +18,7 @@ import imagemin = require('gulp-imagemin');
 import * as rename from 'gulp-rename';
 import * as mocha from 'gulp-mocha';
 import * as replace from 'gulp-replace';
+import * as htmlmin from 'gulp-htmlmin';
 const uglifyes = require('uglify-es');
 import version from './src/version';
 
@@ -161,5 +162,31 @@ gulp.task('build:client:pug', [
 					themeColor: constants.themeColor
 				}
 			}))
+			.pipe(htmlmin({
+				// 真理値属性の簡略化 e.g.
+				// <input value="foo" readonly="readonly"> to
+				// <input value="foo" readonly>
+				collapseBooleanAttributes: true,
+
+				// テキストの一部かもしれない空白も削除する e.g.
+				// <div> <p>    foo </p>    </div> to
+				// <div><p>foo</p></div>
+				collapseWhitespace: true,
+
+				// (できる場合は)属性のクォーテーション削除する e.g.
+				// <p class="foo-bar" id="moo" title="blah blah">foo</p> to
+				// <p class=foo-bar id=moo title="blah blah">foo</p>
+				removeAttributeQuotes: true,
+
+				// 省略可能なタグを省略する e.g.
+				// <html><p>yo</p></html> ro
+				// <p>yo</p>
+				removeOptionalTags: true,
+
+				// 属性の値がデフォルトと同じなら省略する e.g.
+				// <input type="text"> to
+				// <input>
+				removeRedundantAttributes: true
+			}))
 			.pipe(gulp.dest('./built/web/app/'))
 );
diff --git a/package.json b/package.json
index 2cdd516bed..ce98eeb5a7 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
     "@types/express": "4.0.36",
     "@types/gm": "1.17.32",
     "@types/gulp": "4.0.3",
+    "@types/gulp-htmlmin": "1.3.30",
     "@types/gulp-mocha": "0.0.30",
     "@types/gulp-rename": "0.0.32",
     "@types/gulp-replace": "0.0.30",
@@ -70,6 +71,7 @@
     "gulp": "3.9.1",
     "gulp-cssnano": "2.1.2",
     "gulp-imagemin": "3.3.0",
+    "gulp-htmlmin": "3.0.0",
     "gulp-mocha": "4.3.1",
     "gulp-pug": "3.3.0",
     "gulp-rename": "1.2.2",
@@ -148,6 +150,6 @@
     "uuid": "3.1.0",
     "vhost": "3.0.2",
     "websocket": "1.0.24",
-    "xev": "^2.0.0"
+    "xev": "2.0.0"
   }
 }
