diff --git a/sdk/src/main/java/com/deploygate/sdk/DeployGate.java b/sdk/src/main/java/com/deploygate/sdk/DeployGate.java
index 410b09a..500b543 100644
--- a/sdk/src/main/java/com/deploygate/sdk/DeployGate.java
+++ b/sdk/src/main/java/com/deploygate/sdk/DeployGate.java
@@ -55,7 +55,7 @@ public class DeployGate {
     private static final Object sLock = new Object();
     private static CustomAttributes sBuildEnvironment;
     private static CustomAttributes sRuntimeExtra;
-    private static CustomAttributes sSdkDeviceStates;
+    private static SdkDeviceStatesCollector sSdkDeviceStatesCollector;
 
     private static DeployGate sInstance;
 
@@ -152,7 +152,7 @@ public void onEvent(
                     cv.put(DeployGateEvent.ATTRIBUTE_KEY_RUNTIME_EXTRAS, runtimeExtraJSON);
                 }
 
-                String sdkDeviceStatusJSON = getSdkDeviceStates().getJSONString();
+                String sdkDeviceStatusJSON = getSdkDeviceStatesCollector().getJSONString();
                 if (!sdkDeviceStatusJSON.equals("{}")) {
                     cv.put(DeployGateEvent.ATTRIBUTE_KEY_SDK_DEVICE_STATES, sdkDeviceStatusJSON);
                 }
@@ -273,6 +273,8 @@ public void onForeground(
                 long elapsedRealtime,
                 TimeUnit timeUnit
         ) {
+            getSdkDeviceStatesCollector().collectLocale();
+
             Bundle extras = new Bundle();
             extras.putLong(DeployGateEvent.EXTRA_VISIBILITY_EVENT_ELAPSED_REAL_TIME_IN_NANOS, timeUnit.toNanos(elapsedRealtime));
             extras.putInt(DeployGateEvent.EXTRA_VISIBILITY_EVENT_TYPE, DeployGateEvent.VisibilityType.FOREGROUND);
@@ -1709,19 +1711,19 @@ public static CustomAttributes getRuntimeExtra() {
         return sRuntimeExtra;
     }
 
-    private static CustomAttributes getSdkDeviceStates() {
-        if (sSdkDeviceStates != null) {
-            return sSdkDeviceStates;
+    private static SdkDeviceStatesCollector getSdkDeviceStatesCollector() {
+        if (sSdkDeviceStatesCollector != null) {
+            return sSdkDeviceStatesCollector;
         }
 
         synchronized (sLock) {
-            if (sSdkDeviceStates != null) {
-                return sSdkDeviceStates;
+            if (sSdkDeviceStatesCollector != null) {
+                return sSdkDeviceStatesCollector;
             }
-            sSdkDeviceStates = new CustomAttributes();
+            sSdkDeviceStatesCollector = new SdkDeviceStatesCollector();
         }
 
-        return sSdkDeviceStates;
+        return sSdkDeviceStatesCollector;
     }
 
     /**
diff --git a/sdk/src/main/java/com/deploygate/sdk/SdkDeviceStatesCollector.java b/sdk/src/main/java/com/deploygate/sdk/SdkDeviceStatesCollector.java
new file mode 100644
index 0000000..b2657f8
--- /dev/null
+++ b/sdk/src/main/java/com/deploygate/sdk/SdkDeviceStatesCollector.java
@@ -0,0 +1,52 @@
+package com.deploygate.sdk;
+
+import android.os.Build;
+
+import com.deploygate.sdk.internal.Logger;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.Locale;
+
+final class SdkDeviceStatesCollector {
+
+    private final JSONObject states = new JSONObject();
+
+    public String getJSONString() {
+        return states.toString();
+    }
+
+    public void collectLocale() {
+        Locale defaultLocale = Locale.getDefault();
+        String localeClassName = Locale.class.getName();
+        putState(localeClassName, "toString", defaultLocale.toString());
+        putState(localeClassName, "getLanguage", defaultLocale.getLanguage());
+        putState(localeClassName, "getCountry", defaultLocale.getCountry());
+        putState(localeClassName, "getVariant", defaultLocale.getVariant());
+        putState(localeClassName, "getDisplayCountry", defaultLocale.getDisplayCountry());
+        putState(localeClassName, "getDisplayLanguage", defaultLocale.getDisplayLanguage());
+        putState(localeClassName, "getDisplayName", defaultLocale.getDisplayName());
+        putState(localeClassName, "getDisplayVariant", defaultLocale.getDisplayVariant());
+        putState(localeClassName, "getISO3Country", defaultLocale.getISO3Country());
+        putState(localeClassName, "getISO3Language", defaultLocale.getISO3Language());
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            putState(localeClassName, "getDisplayScript", defaultLocale.getDisplayScript());
+            putState(localeClassName, "toLanguageTag", defaultLocale.toLanguageTag());
+        }
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            putState(localeClassName, "getScript", defaultLocale.getScript());
+        }
+    }
+
+    private void putState(String fqcn, String paramName, Object data) {
+        String key = String.format("%s$%s", fqcn, paramName);
+        try {
+            states.put(key, data);
+        } catch (JSONException e) {
+            Logger.w(e, "Failed to put info: key=%s, value=%s", key, data);
+        }
+    }
+}