diff --git a/webnn/resources/test_data/arg_max.json b/webnn/resources/test_data/arg_max.json
index c66f785f416c73..d65939d0477b7c 100644
--- a/webnn/resources/test_data/arg_max.json
+++ b/webnn/resources/test_data/arg_max.json
@@ -471,98 +471,6 @@
         "type": "int32"
       }
     },
-    {
-      "name": "argMax float32 4D tensor options.selectLastIndex=true",
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-          "type": "float32"
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-      "options": {
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-      "expected": {
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-        "shape": [],
-        "data": [
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-        "type": "int32"
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-    {
-      "name": "argMax float32 4D tensor options.selectLastIndex=false",
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-      "expected": {
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     {
       "name": "argMax float32 4D tensor options.axes=[0, 2] options.keepDimensions=false",
       "inputs": {
@@ -663,7 +571,7 @@
       }
     },
     {
-      "name": "argMax float32 4D tensor options.axes=[0, 2] options.selectLastIndex=false",
+      "name": "argMax float32 4D tensor options.axes=[0, 2]",
       "inputs": {
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@@ -697,8 +605,7 @@
         }
       },
       "options": {
-        "axes": [0, 2],
-        "selectLastIndex": false
+        "axes": [0, 2]
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       "expected": {
         "name": "output",
@@ -712,7 +619,7 @@
       }
     },
     {
-      "name": "argMax float32 4D tensor options.axes=[0, 2] options.selectLastIndex=true",
+      "name": "argMax float32 4D tensor options.axes=[3, 0, 1]",
       "inputs": {
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@@ -746,57 +653,7 @@
         }
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       "options": {
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-    {
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-          "type": "float32"
-        }
-      },
-      "options": {
-        "axes": [3, 0, 1],
-        "selectLastIndex": false
+        "axes": [3, 0, 1]
       },
       "expected": {
         "name": "output",
@@ -810,56 +667,6 @@
         "type": "int32"
       }
     },
-    {
-      "name": "argMax float32 4D tensor options.axes=[3, 0, 1] options.selectLastIndex=true",
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       "name": "argMax float32 4D tensor all options",
       "inputs": {
@@ -896,8 +703,7 @@
       },
       "options": {
         "axes": [3, 0],
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-        "selectLastIndex": false
+        "keepDimensions": true
       },
       "expected": {
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@@ -935,7 +741,7 @@
       }
     },
     {
-      "name": "argMax float32 0D scalar options.axes=[] no effect by both keepDimensions and selectLastIndex being true",
+      "name": "argMax float32 0D scalar options.axes=[] no effect by keepDimensions being true",
       "inputs": {
         "input": {
           "shape": [],
@@ -947,8 +753,7 @@
       },
       "options": {
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-        "selectLastIndex": true
+        "keepDimensions": true
       },
       "expected": {
         "name": "output",
diff --git a/webnn/resources/test_data/arg_min.json b/webnn/resources/test_data/arg_min.json
index eaf59f098cc281..f7b3f6d10d6239 100644
--- a/webnn/resources/test_data/arg_min.json
+++ b/webnn/resources/test_data/arg_min.json
@@ -471,98 +471,6 @@
         "type": "int32"
       }
     },
-    {
-      "name": "argMin float32 4D tensor options.selectLastIndex=true",
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-      "expected": {
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-        "type": "int32"
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-    {
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     {
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       "inputs": {
@@ -663,7 +571,7 @@
       }
     },
     {
-      "name": "argMin float32 4D tensor options.axes=[0, 2] options.selectLastIndex=false",
+      "name": "argMin float32 4D tensor options.axes=[0, 2]",
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@@ -697,8 +605,7 @@
         }
       },
       "options": {
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-        "selectLastIndex": false
+        "axes": [0, 2]
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       "expected": {
         "name": "output",
@@ -712,56 +619,7 @@
       }
     },
     {
-      "name": "argMin float32 4D tensor options.axes=[0, 2] options.selectLastIndex=true",
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-    {
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+      "name": "argMin float32 4D tensor options.axes=[3, 0, 1]",
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@@ -795,8 +653,7 @@
         }
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       "options": {
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+        "axes": [3, 0, 1]
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@@ -810,56 +667,6 @@
         "type": "int32"
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     },
-    {
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       "inputs": {
@@ -896,8 +703,7 @@
       },
       "options": {
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-        "selectLastIndex": false
+        "keepDimensions": true
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@@ -935,7 +741,7 @@
       }
     },
     {
-      "name": "argMin float32 0D scalar options.axes=[] no effect by both keepDimensions and selectLastIndex being true",
+      "name": "argMin float32 0D scalar options.axes=[] no effect by keepDimensions being true",
       "inputs": {
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@@ -947,8 +753,7 @@
       },
       "options": {
         "axes": [],
-        "keepDimensions": true,
-        "selectLastIndex": true
+        "keepDimensions": true
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       "expected": {
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