diff --git a/src/main/res/values-zh/strings.xml b/src/main/res/values-zh/strings.xml
index b79e5088..2a2b4c89 100755
--- a/src/main/res/values-zh/strings.xml
+++ b/src/main/res/values-zh/strings.xml
@@ -78,6 +78,11 @@
   <plurals name="bytes">
     <item quantity="other">字节</item>
   </plurals>
+  <string name="connection_test_pending">点击检查是否接入互联网。</string>
+  <string name="connection_test_testing">测试中……</string>
+  <string name="connection_test_available">已接入互联网。（%d 毫秒）</string>
+  <string name="connection_test_error">失败：%s</string>
+  <string name="connection_test_error_status_code">状态码无效。（#%d）</string>
 
   <!-- profile -->
   <string name="add_profile_dialog">为影梭添加此配置文件？</string>
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index d3d7696f..177faac6 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -19,6 +19,11 @@
     <item quantity="one">Byte</item>
     <item quantity="other">Bytes</item>
   </plurals>
+  <string name="connection_test_pending">Tap to check Internet connection availability.</string>
+  <string name="connection_test_testing">Testing…</string>
+  <string name="connection_test_available">Internet connection available. (time=%dms)</string>
+  <string name="connection_test_error">Fail: %s</string>
+  <string name="connection_test_error_status_code">Invalid status code. (#%d)</string>
 
   <!-- proxy category -->
   <string name="proxy_cat">Server Settings</string>
diff --git a/src/main/scala/com/github/shadowsocks/Shadowsocks.scala b/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
index 3e3d0a60..d1de1e87 100644
--- a/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
+++ b/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
@@ -152,6 +152,8 @@ class Shadowsocks
   var prepared = false
   var currentProfile = new Profile
   var vpnEnabled = -1
+  var trafficCache: String = _
+  var connectionTestResult: String = _
 
   // Services
   var currentServiceName = classOf[ShadowsocksNatService].getName
@@ -199,14 +201,17 @@ class Shadowsocks
       })
     }
     def trafficUpdated(txRate: String, rxRate: String, txTotal: String, rxTotal: String) {
-      val trafficStat = getString(R.string.stat_summary)
-        .formatLocal(Locale.ENGLISH, txRate, rxRate, txTotal, rxTotal)
-      handler.post(() => {
-        preferences.findPreference(Key.stat).setSummary(trafficStat)
-      })
+      trafficCache = getString(R.string.stat_summary).formatLocal(Locale.ENGLISH, txRate, rxRate, txTotal, rxTotal)
+      handler.post(updateTraffic)
     }
   }
 
+  def updateTraffic(): Unit = if (trafficCache == null) callback.trafficUpdated(TrafficMonitor.getTxRate,
+    TrafficMonitor.getRxRate, TrafficMonitor.getTxTotal, TrafficMonitor.getRxTotal) else {
+    if (connectionTestResult == null) connectionTestResult = getString(R.string.connection_test_pending)
+    preferences.stat.setSummary(trafficCache + '\n' + connectionTestResult)
+  }
+
   def attachService: Unit = attachService(callback)
 
   override def onServiceConnected() {
@@ -485,8 +490,7 @@ class Shadowsocks
     // Check if current profile changed
     if (ShadowsocksApplication.profileId != currentProfile.id) reloadProfile()
 
-    callback.trafficUpdated(TrafficMonitor.getTxRate, TrafficMonitor.getRxRate,
-      TrafficMonitor.getTxTotal, TrafficMonitor.getRxTotal)
+    updateTraffic()
   }
 
   private def setPreferenceEnabled(enabled: Boolean) {
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksSettings.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksSettings.scala
index 464bb597..bfbc3d68 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksSettings.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksSettings.scala
@@ -1,5 +1,8 @@
 package com.github.shadowsocks
 
+import java.lang.System.currentTimeMillis
+import java.lang.{Long => jLong}
+import java.net.{HttpURLConnection, URL}
 import java.util.Locale
 
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener
@@ -9,20 +12,60 @@ import android.os.{Build, Bundle}
 import android.preference.{Preference, PreferenceFragment, SwitchPreference}
 import android.support.v7.app.AlertDialog
 import android.webkit.{WebView, WebViewClient}
+import com.github.shadowsocks.utils.CloseUtils._
 import com.github.shadowsocks.utils.Key
 
 // TODO: Move related logic here
 class ShadowsocksSettings extends PreferenceFragment with OnSharedPreferenceChangeListener {
   private def activity = getActivity.asInstanceOf[Shadowsocks]
   lazy val natSwitch = findPreference(Key.isNAT).asInstanceOf[SwitchPreference]
+  var stat: Preference = _
 
   private var isProxyApps: SwitchPreference = _
+  private var testCount: Int = _
 
   override def onCreate(savedInstanceState: Bundle) {
     super.onCreate(savedInstanceState)
     addPreferencesFromResource(R.xml.pref_all)
     getPreferenceManager.getSharedPreferences.registerOnSharedPreferenceChangeListener(this)
 
+    stat = findPreference(Key.stat)
+    stat.setOnPreferenceClickListener(_ => {
+      val id = synchronized {
+        testCount += 1
+        activity.connectionTestResult = getString(R.string.connection_test_testing)
+        activity.updateTraffic()
+        testCount
+      }
+      ThrowableFuture {
+        // Based on: https://android.googlesource.com/platform/frameworks/base/+/master/services/core/java/com/android/server/connectivity/NetworkMonitor.java#640
+        autoDisconnect(new URL("https", "www.google.com", "/generate_204").openConnection
+          .asInstanceOf[HttpURLConnection]) { conn =>
+          conn.setInstanceFollowRedirects(false)
+          conn.setUseCaches(false)
+          if (testCount == id) {
+            var result: String = null
+            try {
+              val start = currentTimeMillis
+              conn.getInputStream
+              val elapsed = currentTimeMillis - start
+              val code = conn.getResponseCode
+              if (code == 204 || code == 200 && conn.getContentLength == 0)
+                result = getString(R.string.connection_test_available, elapsed: java.lang.Long)
+              else throw new Exception(getString(R.string.connection_test_error_status_code, code: Integer))
+            } catch {
+              case e: Exception => result = getString(R.string.connection_test_error, e.getMessage)
+            }
+            synchronized(if (testCount == id) {
+              activity.connectionTestResult = result
+              activity.handler.post(activity.updateTraffic)
+            })
+          }
+        }
+      }
+      true
+    })
+
     isProxyApps = findPreference(Key.isProxyApps).asInstanceOf[SwitchPreference]
 
     findPreference("recovery").setOnPreferenceClickListener((preference: Preference) => {
diff --git a/src/main/scala/com/github/shadowsocks/utils/CloseUtils.scala b/src/main/scala/com/github/shadowsocks/utils/CloseUtils.scala
new file mode 100644
index 00000000..edd85aeb
--- /dev/null
+++ b/src/main/scala/com/github/shadowsocks/utils/CloseUtils.scala
@@ -0,0 +1,35 @@
+package com.github.shadowsocks.utils
+
+/**
+  * @author Mygod
+  */
+object CloseUtils {
+  type Disconnectable = {
+    def disconnect()
+  }
+
+  def autoClose[A <: AutoCloseable, B](x: => A)(block: A => B): B = {
+    var a: Option[A] = None
+    try {
+      a = Some(x)
+      block(a.get)
+    } finally if (a.nonEmpty) try {
+      val v = a.get
+      if (v ne null) v.close
+    } catch {
+      case ignore: Exception =>
+    }
+  }
+  def autoDisconnect[A <: Disconnectable, B](x: => A)(block: A => B): B = {
+    var a: Option[A] = None
+    try {
+      a = Some(x)
+      block(a.get)
+    } finally if (a.nonEmpty) try {
+      val v = a.get
+      if (v ne null) v.disconnect
+    } catch {
+      case ignore: Exception =>
+    }
+  }
+}