diff --git a/core/src/main/scala/org/apache/spark/status/api/v1/StagesResource.scala b/core/src/main/scala/org/apache/spark/status/api/v1/StagesResource.scala
index 84bd430d9abe..24c987187049 100644
--- a/core/src/main/scala/org/apache/spark/status/api/v1/StagesResource.scala
+++ b/core/src/main/scala/org/apache/spark/status/api/v1/StagesResource.scala
@@ -74,7 +74,7 @@ private[v1] class StagesResource extends BaseAppResource {
   def taskSummary(
       @PathParam("stageId") stageId: Int,
       @PathParam("stageAttemptId") stageAttemptId: Int,
-      @DefaultValue("0.05,0.25,0.5,0.75,0.95") @QueryParam("quantiles") quantileString: String)
+      @DefaultValue("0,0.25,0.5,0.75,1.0") @QueryParam("quantiles") quantileString: String)
   : TaskMetricDistributions = withUI { ui =>
     val quantiles = quantileString.split(",").map { s =>
       try {
diff --git a/core/src/test/resources/HistoryServerExpectations/stage_task_summary_w_shuffle_read_expectation.json b/core/src/test/resources/HistoryServerExpectations/stage_task_summary_w_shuffle_read_expectation.json
index e6b705989cc9..ab59545e87cd 100644
--- a/core/src/test/resources/HistoryServerExpectations/stage_task_summary_w_shuffle_read_expectation.json
+++ b/core/src/test/resources/HistoryServerExpectations/stage_task_summary_w_shuffle_read_expectation.json
@@ -1,5 +1,5 @@
 {
-  "quantiles" : [ 0.05, 0.25, 0.5, 0.75, 0.95 ],
+  "quantiles" : [ 0.0, 0.25, 0.5, 0.75, 1.0 ],
   "executorDeserializeTime" : [ 1.0, 2.0, 2.0, 2.0, 3.0 ],
   "executorDeserializeCpuTime" : [ 0.0, 0.0, 0.0, 0.0, 0.0 ],
   "executorRunTime" : [ 30.0, 74.0, 75.0, 76.0, 79.0 ],
diff --git a/core/src/test/resources/HistoryServerExpectations/stage_task_summary_w_shuffle_write_expectation.json b/core/src/test/resources/HistoryServerExpectations/stage_task_summary_w_shuffle_write_expectation.json
index 788f28cf7b36..1b074c2bfece 100644
--- a/core/src/test/resources/HistoryServerExpectations/stage_task_summary_w_shuffle_write_expectation.json
+++ b/core/src/test/resources/HistoryServerExpectations/stage_task_summary_w_shuffle_write_expectation.json
@@ -1,19 +1,19 @@
 {
-  "quantiles" : [ 0.05, 0.25, 0.5, 0.75, 0.95 ],
-  "executorDeserializeTime" : [ 2.0, 2.0, 3.0, 7.0, 31.0 ],
+  "quantiles" : [ 0.0, 0.25, 0.5, 0.75, 1.0 ],
+  "executorDeserializeTime" : [ 1.0, 2.0, 3.0, 7.0, 36.0 ],
   "executorDeserializeCpuTime" : [ 0.0, 0.0, 0.0, 0.0, 0.0 ],
-  "executorRunTime" : [ 16.0, 18.0, 28.0, 49.0, 349.0 ],
+  "executorRunTime" : [ 14.0, 18.0, 28.0, 49.0, 351.0 ],
   "executorCpuTime" : [ 0.0, 0.0, 0.0, 0.0, 0.0 ],
   "resultSize" : [ 2010.0, 2065.0, 2065.0, 2065.0, 2065.0 ],
   "jvmGcTime" : [ 0.0, 0.0, 0.0, 5.0, 7.0 ],
-  "resultSerializationTime" : [ 0.0, 0.0, 0.0, 0.0, 1.0 ],
+  "resultSerializationTime" : [ 0.0, 0.0, 0.0, 0.0, 2.0 ],
   "gettingResultTime" : [ 0.0, 0.0, 0.0, 0.0, 0.0 ],
-  "schedulerDelay" : [ 2.0, 4.0, 6.0, 13.0, 40.0 ],
+  "schedulerDelay" : [ 2.0, 4.0, 6.0, 13.0, 53.0 ],
   "peakExecutionMemory" : [ 0.0, 0.0, 0.0, 0.0, 0.0 ],
   "memoryBytesSpilled" : [ 0.0, 0.0, 0.0, 0.0, 0.0 ],
   "diskBytesSpilled" : [ 0.0, 0.0, 0.0, 0.0, 0.0 ],
   "inputMetrics" : {
-    "bytesRead" : [ 60488.0, 70564.0, 70564.0, 70564.0, 70564.0 ],
+    "bytesRead" : [ 49294.0, 70564.0, 70564.0, 70564.0, 70565.0 ],
     "recordsRead" : [ 10000.0, 10000.0, 10000.0, 10000.0, 10000.0 ]
   },
   "outputMetrics" : {
@@ -33,6 +33,6 @@
   "shuffleWriteMetrics" : {
     "writeBytes" : [ 1710.0, 1710.0, 1710.0, 1710.0, 1710.0 ],
     "writeRecords" : [ 10.0, 10.0, 10.0, 10.0, 10.0 ],
-    "writeTime" : [ 90329.0, 95848.0, 102159.0, 121551.0, 2579051.0 ]
+    "writeTime" : [ 83022.0, 95848.0, 102159.0, 121551.0, 4016617.0 ]
   }
 }
diff --git a/docs/monitoring.md b/docs/monitoring.md
index 5b3278bca031..a5e5244fa8c1 100644
--- a/docs/monitoring.md
+++ b/docs/monitoring.md
@@ -490,6 +490,7 @@ can be identified by their `[attempt-id]`. In the API listed below, when running
     <td>
       Summary metrics of all tasks in the given stage attempt.
       <br><code>?quantiles</code> summarize the metrics with the given quantiles.
+      <br>The default value is <code>0.0,0.25,0.5,0.75,1.0</code>.
       <br>Example: <code>?quantiles=0.01,0.5,0.99</code>
     </td>
   </tr>