diff --git a/app/templating/StringHelper.scala b/app/templating/StringHelper.scala
index 7da8bc4701..7456a492ec 100644
--- a/app/templating/StringHelper.scala
+++ b/app/templating/StringHelper.scala
@@ -1,15 +1,15 @@
 package lila.app
 package templating
 
-import lila.user.{ User, UserContext }
 import play.twirl.api.Html
 
+import lila.common.String.html.{ encode => escapeHtml }
+import lila.user.{ User, UserContext }
+
 trait StringHelper { self: NumberHelper =>
 
   def netDomain: String
 
-  val escapeHtml: String => String = org.apache.commons.lang3.StringEscapeUtils.escapeHtml4 _
-
   val slugify = lila.common.String.slugify _
 
   def shorten(text: String, length: Int, sep: String = "…") = Html {
diff --git a/app/ui/OpenGraph.scala b/app/ui/OpenGraph.scala
index bf20c4b289..a8e7d6f729 100644
--- a/app/ui/OpenGraph.scala
+++ b/app/ui/OpenGraph.scala
@@ -1,7 +1,7 @@
 package lila.app
 package ui
 
-import org.apache.commons.lang3.StringEscapeUtils.escapeHtml4
+import lila.common.String.html.{ encode => escapeHtml }
 import play.twirl.api.Html
 
 case class OpenGraph(
@@ -19,7 +19,7 @@ case class OpenGraph(
   object og {
 
     private def tag(name: String, value: String) =
-      s"""<meta property="og:$name" content="${escapeHtml4(value)}"/>"""
+      s"""<meta property="og:$name" content="${escapeHtml(value)}"/>"""
 
     private val tupledTag = (tag _).tupled
 
@@ -37,7 +37,7 @@ case class OpenGraph(
   object twitter {
 
     private def tag(name: String, value: String) =
-      s"""<meta name="twitter:$name" content="${escapeHtml4(value)}"/>"""
+      s"""<meta name="twitter:$name" content="${escapeHtml(value)}"/>"""
 
     private val tupledTag = (tag _).tupled
 
diff --git a/modules/chat/src/main/JsonView.scala b/modules/chat/src/main/JsonView.scala
index 3ef715b251..8827947fef 100644
--- a/modules/chat/src/main/JsonView.scala
+++ b/modules/chat/src/main/JsonView.scala
@@ -2,26 +2,26 @@ package lila.chat
 
 import lila.common.LightUser
 import lila.common.PimpedJson._
-import org.apache.commons.lang3.StringEscapeUtils.escapeHtml4
+import lila.common.String.html.{ encode => escapeHtml }
 import play.api.libs.json._
 
 object JsonView {
 
   def apply(chat: AnyChat, mobileEscape: Boolean = false): JsValue = {
-    if (mobileEscape) escapeHtml(chat)
+    if (mobileEscape) escapeHtmlForMobile(chat)
     else chat
   } match {
     case c: MixedChat => mixedChatWriter writes c
     case c: UserChat => userChatWriter writes c
   }
 
-  private def escapeHtml(chat: AnyChat) = chat match {
+  private def escapeHtmlForMobile(chat: AnyChat) = chat match {
     case c: MixedChat => c.mapLines {
-      case l: UserLine => l.copy(text = escapeHtml4(l.text))
-      case l: PlayerLine => l.copy(text = escapeHtml4(l.text))
+      case l: UserLine => l.copy(text = escapeHtml(l.text))
+      case l: PlayerLine => l.copy(text = escapeHtml(l.text))
     }
     case c: UserChat => c.mapLines { l =>
-      l.copy(text = escapeHtml4(l.text))
+      l.copy(text = escapeHtml(l.text))
     }
   }
 
diff --git a/modules/common/src/main/String.scala b/modules/common/src/main/String.scala
index 547d0672c8..a51c7f3c13 100644
--- a/modules/common/src/main/String.scala
+++ b/modules/common/src/main/String.scala
@@ -51,6 +51,7 @@ object String {
 
   object html {
 
+    // from https://github.com/android/platform_frameworks_base/blob/d59921149bb5948ffbcb9a9e832e9ac1538e05a0/core/java/android/text/TextUtils.java#L1361
     def encode(s: String): String = {
       val sb = new StringBuilder
       for (i <- 0 to s.length) sb.append {
diff --git a/modules/i18n/src/main/Translator.scala b/modules/i18n/src/main/Translator.scala
index ce9b8e785e..fcf5b59707 100644
--- a/modules/i18n/src/main/Translator.scala
+++ b/modules/i18n/src/main/Translator.scala
@@ -2,7 +2,6 @@ package lila.i18n
 
 import play.api.i18n.Lang
 import play.api.mvc.RequestHeader
-import play.twirl.api.Html
 
 private sealed trait Translation extends Any
 
diff --git a/modules/round/src/main/JsonView.scala b/modules/round/src/main/JsonView.scala
index fa9e1ee465..8a2606af6b 100644
--- a/modules/round/src/main/JsonView.scala
+++ b/modules/round/src/main/JsonView.scala
@@ -3,11 +3,11 @@ package lila.round
 import scala.concurrent.duration._
 import scala.math
 
-import org.apache.commons.lang3.StringEscapeUtils.escapeHtml4
 import play.api.libs.json._
 
 import lila.common.ApiVersion
 import lila.common.PimpedJson._
+import lila.common.String.html.{ encode => escapeHtml }
 import lila.game.JsonView._
 import lila.game.{ Pov, Game, PerfPicker, Source, GameRepo, CorrespondenceClock }
 import lila.pref.Pref
@@ -156,7 +156,7 @@ final class JsonView(
               "spectator" -> true,
               "ai" -> player.aiLevel,
               "user" -> playerUser.map { userJsonView.minimal(_, game.perfType) },
-              "name" -> player.name.map(escapeHtml4),
+              "name" -> player.name.map(escapeHtml),
               "rating" -> player.rating,
               "ratingDiff" -> player.ratingDiff,
               "provisional" -> player.provisional.option(true),
@@ -170,7 +170,7 @@ final class JsonView(
               "color" -> opponent.color.name,
               "ai" -> opponent.aiLevel,
               "user" -> opponentUser.map { userJsonView.minimal(_, game.perfType) },
-              "name" -> opponent.name.map(escapeHtml4),
+              "name" -> opponent.name.map(escapeHtml),
               "rating" -> opponent.rating,
               "ratingDiff" -> opponent.ratingDiff,
               "provisional" -> opponent.provisional.option(true),
diff --git a/modules/round/src/main/VersionedEvent.scala b/modules/round/src/main/VersionedEvent.scala
index 2fc58828d1..d05f28484f 100644
--- a/modules/round/src/main/VersionedEvent.scala
+++ b/modules/round/src/main/VersionedEvent.scala
@@ -6,7 +6,7 @@ import actorApi.Member
 import chess.Color
 import lila.common.ApiVersion
 import lila.game.Event
-import org.apache.commons.lang3.StringEscapeUtils.escapeHtml4
+import lila.common.String.html.{ encode => escapeHtml }
 
 case class VersionedEvent(
     version: Int,
@@ -34,7 +34,7 @@ case class VersionedEvent(
   else Json.obj("v" -> version)
 
   private val mobileV1Escaper: Reads[JsObject] = (__ \ 't).json.update(
-    __.read[JsString].map { s => JsString(escapeHtml4(s.value)) }
+    __.read[JsString].map { s => JsString(escapeHtml(s.value)) }
   )
 
   private def dataForApiVersion(typ: String, data: JsValue, apiVersion: ApiVersion): JsValue =