diff --git a/js/web/lib/wasm/jsep/backend-webnn.ts b/js/web/lib/wasm/jsep/backend-webnn.ts
index 860424d31ffab..0bb1b09687018 100644
--- a/js/web/lib/wasm/jsep/backend-webnn.ts
+++ b/js/web/lib/wasm/jsep/backend-webnn.ts
@@ -97,6 +97,10 @@ export class WebNNBackend {
    * Temporary tensors for the current session.
    */
   private temporarySessionTensorIds: Map<number, TensorId[]> = new Map();
+  /**
+   * Maps from session id to MLOpSupportLimits.
+   */
+  private mlOpSupportLimitsBySessionId = new Map<number, MLOpSupportLimits>();
 
   constructor(env: Env) {
     configureLogger(env.logLevel!, !!env.debug);
@@ -172,6 +176,10 @@ export class WebNNBackend {
     }
     sessionIds.add(sessionId);
 
+    if (!this.mlOpSupportLimitsBySessionId.has(sessionId)) {
+      this.mlOpSupportLimitsBySessionId.set(sessionId, mlContext.opSupportLimits());
+    }
+
     if (this.temporaryGraphInputs.length > 0) {
       this.sessionGraphInputs.set(sessionId, this.temporaryGraphInputs);
       this.temporaryGraphInputs = [];
@@ -192,6 +200,7 @@ export class WebNNBackend {
     }
     this.tensorManager.releaseTensorsForSession(sessionId);
     this.mlContextBySessionId.delete(sessionId);
+    this.mlOpSupportLimitsBySessionId.delete(sessionId);
     const sessionIds = this.sessionIdsByMLContext.get(mlContext)!;
     sessionIds.delete(sessionId);
     if (sessionIds.size === 0) {
@@ -207,6 +216,10 @@ export class WebNNBackend {
     return this.mlContextBySessionId.get(sessionId);
   }
 
+  public getMLOpSupportLimits(sessionId: number): MLOpSupportLimits | undefined {
+    return this.mlOpSupportLimitsBySessionId.get(sessionId);
+  }
+
   public reserveTensorId(): TensorId {
     return this.tensorManager.reserveTensorId();
   }
@@ -399,17 +412,17 @@ export class WebNNBackend {
   }
 
   public isGraphInputOutputTypeSupported(sessionId: number, type: Tensor.Type, isInput = true): boolean {
-    const context = this.mlContextBySessionId.get(sessionId);
     const dataType = onnxDataTypeToWebnnDataType.get(tensorDataTypeStringToEnum(type));
+    const opLimits = this.mlOpSupportLimitsBySessionId.get(sessionId);
 
     if (typeof dataType === 'undefined') {
       return false;
     }
 
     if (isInput) {
-      return !!context?.opSupportLimits().input.dataTypes.includes(dataType);
+      return !!opLimits?.input.dataTypes.includes(dataType);
     } else {
-      return !!context?.opSupportLimits().output.dataTypes.includes(dataType);
+      return !!opLimits?.output.dataTypes.includes(dataType);
     }
   }
 
diff --git a/js/web/lib/wasm/jsep/webnn/tensor-manager.ts b/js/web/lib/wasm/jsep/webnn/tensor-manager.ts
index 784e5ab53c1fa..70a2a9a892470 100644
--- a/js/web/lib/wasm/jsep/webnn/tensor-manager.ts
+++ b/js/web/lib/wasm/jsep/webnn/tensor-manager.ts
@@ -336,11 +336,12 @@ class TensorIdTracker {
     copyOld: boolean,
   ): Promise<MLTensor> {
     const context = this.tensorManager.getMLContext(sessionId);
+    const opLimits = this.tensorManager.getMLOpSupportLimits(sessionId);
     let fallbackDataType: MLOperandDataType | undefined;
     // Check if the context supports the data type. If not, try to use the fallback data type.
-    if (!context.opSupportLimits().input.dataTypes.includes(dataType)) {
+    if (!opLimits?.input.dataTypes.includes(dataType)) {
       fallbackDataType = webnnDataTypeToFallback.get(dataType);
-      if (!fallbackDataType || !context.opSupportLimits().input.dataTypes.includes(fallbackDataType)) {
+      if (!fallbackDataType || opLimits?.input.dataTypes.includes(fallbackDataType)) {
         throw new Error(`WebNN backend does not support data type: ${dataType}`);
       }
       LOG_DEBUG(
@@ -460,6 +461,10 @@ class TensorManagerImpl implements TensorManager {
     return context;
   }
 
+  public getMLOpSupportLimits(sessionId: number): MLOpSupportLimits | undefined {
+    return this.backend.getMLOpSupportLimits(sessionId);
+  }
+
   public reserveTensorId(): TensorId {
     const tensorId = createNewTensorId();
     this.tensorTrackersById.set(tensorId, new TensorIdTracker(this));
diff --git a/onnxruntime/core/providers/webnn/data_transfer.cc b/onnxruntime/core/providers/webnn/data_transfer.cc
index 17369e6fbc75d..6b5bed4ecdeae 100644
--- a/onnxruntime/core/providers/webnn/data_transfer.cc
+++ b/onnxruntime/core/providers/webnn/data_transfer.cc
@@ -35,19 +35,17 @@ common::Status DataTransfer::CopyTensor(const Tensor& src, Tensor& dst) const {
 
     if (dst_device.Type() == OrtDevice::GPU) {
       EM_ASM({ Module.webnnUploadTensor($0, HEAPU8.subarray($1, $1 + $2)); }, dst_data, reinterpret_cast<intptr_t>(src_data), bytes);
-      if (trace) {
-        console.call<void>("timeEnd", emscripten::val("ORT::DataTransfer::webnnUploadTensor"));
-      }
     } else {
       auto webnnDownloadTensor = emscripten::val::module_property("webnnDownloadTensor");
       auto subarray = emscripten::typed_memory_view(bytes, static_cast<char*>(dst_data));
       webnnDownloadTensor(reinterpret_cast<intptr_t>(src_data), subarray).await();
-      if (trace) {
-        console.call<void>("timeEnd", emscripten::val("ORT::DataTransfer::webnnDownloadTensor"));
-      }
     }
   }
 
+  if (trace) {
+    console.call<void>("timeEnd", emscripten::val("ORT::DataTransfer::CopyTensor"));
+  }
+
   return Status::OK();
 }