diff --git a/examples/demo-apps/android/LlamaDemo/app/build.gradle.kts b/examples/demo-apps/android/LlamaDemo/app/build.gradle.kts
index ea9d4e6c172..893b1ee4784 100644
--- a/examples/demo-apps/android/LlamaDemo/app/build.gradle.kts
+++ b/examples/demo-apps/android/LlamaDemo/app/build.gradle.kts
@@ -60,6 +60,7 @@ dependencies {
   implementation(files("libs/executorch.aar"))
   implementation("com.google.android.material:material:1.12.0")
   implementation("androidx.activity:activity:1.9.0")
+  implementation("org.json:json:20250107")
   testImplementation("junit:junit:4.13.2")
   androidTestImplementation("androidx.test.ext:junit:1.1.5")
   androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")
diff --git a/examples/demo-apps/android/LlamaDemo/app/src/androidTest/java/com/example/executorchllamademo/PerfTest.java b/examples/demo-apps/android/LlamaDemo/app/src/androidTest/java/com/example/executorchllamademo/PerfTest.java
index 21ac285d3b0..32ec24a0df9 100644
--- a/examples/demo-apps/android/LlamaDemo/app/src/androidTest/java/com/example/executorchllamademo/PerfTest.java
+++ b/examples/demo-apps/android/LlamaDemo/app/src/androidTest/java/com/example/executorchllamademo/PerfTest.java
@@ -18,6 +18,8 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import org.json.JSONException;
+import org.json.JSONObject;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.pytorch.executorch.extension.llm.LlmCallback;
@@ -64,8 +66,16 @@ public void onResult(String result) {
   }
 
   @Override
-  public void onStats(float tps) {
-    tokensPerSecond.add(tps);
+  public void onStats(String result) {
+    try {
+      JSONObject jsonObject = new JSONObject(result);
+      int numGeneratedTokens = jsonObject.getInt("generated_tokens");
+      int inferenceEndMs = jsonObject.getInt("inference_end_ms");
+      int promptEvalEndMs = jsonObject.getInt("prompt_eval_end_ms");
+      float tps = (float) numGeneratedTokens / (inferenceEndMs - promptEvalEndMs) * 1000;
+      tokensPerSecond.add(tps);
+    } catch (JSONException e) {
+    }
   }
 
   private void report(final String metric, final Float value) {
diff --git a/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/MainActivity.java b/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/MainActivity.java
index e19155b83e8..137e01f8f43 100644
--- a/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/MainActivity.java
+++ b/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/MainActivity.java
@@ -49,6 +49,8 @@
 import java.util.List;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
+import org.json.JSONException;
+import org.json.JSONObject;
 import org.pytorch.executorch.extension.llm.LlmCallback;
 import org.pytorch.executorch.extension.llm.LlmModule;
 
@@ -97,10 +99,20 @@ public void onResult(String result) {
   }
 
   @Override
-  public void onStats(float tps) {
+  public void onStats(String stats) {
     runOnUiThread(
         () -> {
           if (mResultMessage != null) {
+            float tps = 0;
+            try {
+              JSONObject jsonObject = new JSONObject(stats);
+              int numGeneratedTokens = jsonObject.getInt("generated_tokens");
+              int inferenceEndMs = jsonObject.getInt("inference_end_ms");
+              int promptEvalEndMs = jsonObject.getInt("prompt_eval_end_ms");
+              tps = (float) numGeneratedTokens / (inferenceEndMs - promptEvalEndMs) * 1000;
+            } catch (JSONException e) {
+              Log.e("LLM", "Error parsing JSON: " + e.getMessage());
+            }
             mResultMessage.setTokensPerSecond(tps);
             mMessageAdapter.notifyDataSetChanged();
           }
diff --git a/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ModelRunner.java b/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ModelRunner.java
index 78cfee993c4..a1bc205c4ac 100644
--- a/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ModelRunner.java
+++ b/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ModelRunner.java
@@ -13,6 +13,8 @@
 import android.os.Looper;
 import android.os.Message;
 import androidx.annotation.NonNull;
+import org.json.JSONException;
+import org.json.JSONObject;
 import org.pytorch.executorch.extension.llm.LlmCallback;
 import org.pytorch.executorch.extension.llm.LlmModule;
 
@@ -69,7 +71,16 @@ public void onResult(String result) {
   }
 
   @Override
-  public void onStats(float tps) {
+  public void onStats(String stats) {
+    float tps = 0;
+    try {
+      JSONObject jsonObject = new JSONObject(stats);
+      int numGeneratedTokens = jsonObject.getInt("generated_tokens");
+      int inferenceEndMs = jsonObject.getInt("inference_end_ms");
+      int promptEvalEndMs = jsonObject.getInt("prompt_eval_end_ms");
+      tps = (float) numGeneratedTokens / (inferenceEndMs - promptEvalEndMs) * 1000;
+    } catch (JSONException e) {
+    }
     mCallback.onStats("tokens/second: " + tps);
   }
 }
diff --git a/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ModelRunnerCallback.java b/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ModelRunnerCallback.java
index c8bdc53075e..5e8b6f00e3d 100644
--- a/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ModelRunnerCallback.java
+++ b/examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ModelRunnerCallback.java
@@ -18,7 +18,7 @@ public interface ModelRunnerCallback {
 
   void onTokenGenerated(String token);
 
-  void onStats(String token);
+  void onStats(String stats);
 
   void onGenerationStopped();
 }
diff --git a/extension/android/executorch_android/build.gradle b/extension/android/executorch_android/build.gradle
index b1bc090759a..15088f4097f 100644
--- a/extension/android/executorch_android/build.gradle
+++ b/extension/android/executorch_android/build.gradle
@@ -47,6 +47,7 @@ dependencies {
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test:rules:1.2.0'
     androidTestImplementation 'commons-io:commons-io:2.4'
+    androidTestImplementation 'org.json:json:20250107'
 }
 
 import com.vanniktech.maven.publish.SonatypeHost
diff --git a/extension/android/executorch_android/src/androidTest/java/org/pytorch/executorch/LlmModuleInstrumentationTest.java b/extension/android/executorch_android/src/androidTest/java/org/pytorch/executorch/LlmModuleInstrumentationTest.java
index e95b42f2650..3791938c3bc 100644
--- a/extension/android/executorch_android/src/androidTest/java/org/pytorch/executorch/LlmModuleInstrumentationTest.java
+++ b/extension/android/executorch_android/src/androidTest/java/org/pytorch/executorch/LlmModuleInstrumentationTest.java
@@ -34,6 +34,8 @@
 import org.apache.commons.io.FileUtils;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.InstrumentationRegistry;
+import org.json.JSONException;
+import org.json.JSONObject;
 import org.pytorch.executorch.extension.llm.LlmCallback;
 import org.pytorch.executorch.extension.llm.LlmModule;
 
@@ -94,8 +96,17 @@ public void onResult(String result) {
             }
 
             @Override
-            public void onStats(float tps) {
-                LlmModuleInstrumentationTest.this.onStats(tps);
+            public void onStats(String stats) {
+                float tps = 0;
+                try {
+                    JSONObject jsonObject = new JSONObject(stats);
+                    int numGeneratedTokens = jsonObject.getInt("generated_tokens");
+                    int inferenceEndMs = jsonObject.getInt("inference_end_ms");
+                    int promptEvalEndMs = jsonObject.getInt("prompt_eval_end_ms");
+                    tps = (float) numGeneratedTokens / (inferenceEndMs - promptEvalEndMs) * 1000;
+                    LlmModuleInstrumentationTest.this.onStats(tps);
+                } catch (JSONException e) {
+                }
             }
         });
 
diff --git a/extension/android/executorch_android/src/main/java/org/pytorch/executorch/extension/llm/LlmCallback.java b/extension/android/executorch_android/src/main/java/org/pytorch/executorch/extension/llm/LlmCallback.java
index c05b30b0625..a829cf75dc4 100644
--- a/extension/android/executorch_android/src/main/java/org/pytorch/executorch/extension/llm/LlmCallback.java
+++ b/extension/android/executorch_android/src/main/java/org/pytorch/executorch/extension/llm/LlmCallback.java
@@ -31,8 +31,22 @@ public interface LlmCallback {
   /**
    * Called when the statistics for the generate() is available.
    *
+   * Note: This is a deprecated API and will be removed in the future. Please use onStats(String stats)
+   *
    * @param tps Tokens/second for generated tokens.
    */
+  @Deprecated
+  @DoNotStrip
+  default public void onStats(float tps) {}
+
+  /**
+   * Called when the statistics for the generate() is available.
+   *
+   * The result will be a JSON string. See extension/llm/stats.h for the field
+   * definitions.
+   *
+   * @param stats JSON string containing the statistics for the generate()
+   */
   @DoNotStrip
-  public void onStats(float tps);
+  default public void onStats(String stats) {}
 }
diff --git a/extension/android/jni/jni_layer_llama.cpp b/extension/android/jni/jni_layer_llama.cpp
index edb67bdabea..4a98ccb7c82 100644
--- a/extension/android/jni/jni_layer_llama.cpp
+++ b/extension/android/jni/jni_layer_llama.cpp
@@ -100,14 +100,20 @@ class ExecuTorchLlmCallbackJni
 
   void onStats(const llm::Stats& result) const {
     static auto cls = ExecuTorchLlmCallbackJni::javaClassStatic();
-    static const auto method = cls->getMethod<void(jfloat)>("onStats");
+    static const auto tps_method = cls->getMethod<void(jfloat)>("onStats");
     double eval_time =
         (double)(result.inference_end_ms - result.prompt_eval_end_ms);
 
     float tps = result.num_generated_tokens / eval_time *
         result.SCALING_FACTOR_UNITS_PER_SECOND;
-
-    method(self(), tps);
+    tps_method(self(), tps);
+
+    static const auto on_stats_method =
+        cls->getMethod<void(facebook::jni::local_ref<jstring>)>("onStats");
+    on_stats_method(
+        self(),
+        facebook::jni::make_jstring(
+            executorch::extension::llm::stats_to_json_string(result)));
   }
 };
 
diff --git a/extension/benchmark/android/benchmark/app/build.gradle.kts b/extension/benchmark/android/benchmark/app/build.gradle.kts
index dcf99ca9cd0..28dfc8ae49d 100644
--- a/extension/benchmark/android/benchmark/app/build.gradle.kts
+++ b/extension/benchmark/android/benchmark/app/build.gradle.kts
@@ -39,6 +39,7 @@ dependencies {
   implementation("com.facebook.soloader:soloader:0.10.5")
   implementation("com.facebook.fbjni:fbjni:0.5.1")
   implementation("com.google.code.gson:gson:2.8.6")
+  implementation("org.json:json:20250107")
   testImplementation("junit:junit:4.13.2")
   androidTestImplementation("androidx.test.ext:junit:1.2.1")
   androidTestImplementation("androidx.test.espresso:espresso-core:3.6.1")
diff --git a/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/LlmBenchmarkActivity.java b/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/LlmBenchmarkActivity.java
index 3bc38aad403..8db2e8633ad 100644
--- a/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/LlmBenchmarkActivity.java
+++ b/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/LlmBenchmarkActivity.java
@@ -23,6 +23,8 @@
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import org.json.JSONException;
+import org.json.JSONObject;
 
 public class LlmBenchmarkActivity extends Activity implements ModelRunnerCallback {
   ModelRunner mModelRunner;
@@ -80,7 +82,17 @@ public void onTokenGenerated(String token) {}
 
   @Override
   public void onStats(String stats) {
-    mStatsInfo.tokens = stats;
+    float tps = 0;
+    try {
+      JSONObject jsonObject = new JSONObject(stats);
+      int numGeneratedTokens = jsonObject.getInt("generated_tokens");
+      int inferenceEndMs = jsonObject.getInt("inference_end_ms");
+      int promptEvalEndMs = jsonObject.getInt("prompt_eval_end_ms");
+      tps = (float) numGeneratedTokens / (inferenceEndMs - promptEvalEndMs) * 1000;
+      mStatsInfo.tps = tps;
+    } catch (JSONException e) {
+      Log.e("LLM", "Error parsing JSON: " + e.getMessage());
+    }
   }
 
   @Override
@@ -109,7 +121,7 @@ public void onGenerationStopped() {
             0.0f));
     // Token per second
     results.add(
-        new BenchmarkMetric(benchmarkModel, "token_per_sec", extractTPS(mStatsInfo.tokens), 0.0f));
+        new BenchmarkMetric(benchmarkModel, "token_per_sec", mStatsInfo.tps, 0.0f));
 
     try (FileWriter writer = new FileWriter(getFilesDir() + "/benchmark_results.json")) {
       Gson gson = new Gson();
@@ -118,15 +130,6 @@ public void onGenerationStopped() {
       e.printStackTrace();
     }
   }
-
-  private double extractTPS(final String tokens) {
-    final Matcher m = Pattern.compile("\\d+\\.?\\d*").matcher(tokens);
-    if (m.find()) {
-      return Double.parseDouble(m.group());
-    } else {
-      return 0.0f;
-    }
-  }
 }
 
 class StatsInfo {
@@ -135,7 +138,7 @@ class StatsInfo {
   long loadEnd;
   long generateStart;
   long generateEnd;
-  String tokens;
+  float tps;
   String modelName;
 
   @Override
@@ -149,6 +152,6 @@ public String toString() {
         + "\ngenerateEnd: "
         + generateEnd
         + "\n"
-        + tokens;
+        + tps;
   }
 }
diff --git a/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/ModelRunner.java b/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/ModelRunner.java
index 6ba1f57c4f3..0a75b47f3a6 100644
--- a/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/ModelRunner.java
+++ b/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/ModelRunner.java
@@ -68,8 +68,8 @@ public void onResult(String result) {
   }
 
   @Override
-  public void onStats(float tps) {
-    mCallback.onStats("tokens/second: " + tps);
+  public void onStats(String result) {
+    mCallback.onStats(result);
   }
 }
 
diff --git a/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/ModelRunnerCallback.java b/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/ModelRunnerCallback.java
index 63701a7bbc6..8503d47ccce 100644
--- a/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/ModelRunnerCallback.java
+++ b/extension/benchmark/android/benchmark/app/src/main/java/org/pytorch/minibench/ModelRunnerCallback.java
@@ -18,7 +18,7 @@ public interface ModelRunnerCallback {
 
   void onTokenGenerated(String token);
 
-  void onStats(String token);
+  void onStats(String result);
 
   void onGenerationStopped();
 }