diff --git a/backends/webgpu/runtime/ops/sdpa/sdpa_compute_attn_weights.wgsl b/backends/webgpu/runtime/ops/sdpa/sdpa_compute_attn_weights.wgsl
index e694a6b223c..9a5cd614f8b 100644
--- a/backends/webgpu/runtime/ops/sdpa/sdpa_compute_attn_weights.wgsl
+++ b/backends/webgpu/runtime/ops/sdpa/sdpa_compute_attn_weights.wgsl
@@ -85,9 +85,11 @@ fn main(@builtin(global_invocation_id) gid: vec3<u32>) {
   acc[2] = vec4<f32>(0.0, 0.0, 0.0, 0.0);
   acc[3] = vec4<f32>(0.0, 0.0, 0.0, 0.0);
 
+  // Skip fully-masked causal tiles; mirrors Vulkan attn_weights_tiled.glsl.
+  let skip_tile = c0 > s0 + (TM - 1u) + params.input_pos;
   var d4: u32 = 0u;
   loop {
-    if (d4 >= params.D) {
+    if (d4 >= params.D || skip_tile) {
       break;
     }
     var q: array<vec4<f32>, TM>;
diff --git a/backends/webgpu/runtime/ops/sdpa/sdpa_compute_attn_weights_wgsl.h b/backends/webgpu/runtime/ops/sdpa/sdpa_compute_attn_weights_wgsl.h
index 3d027b417f0..144af9b5956 100644
--- a/backends/webgpu/runtime/ops/sdpa/sdpa_compute_attn_weights_wgsl.h
+++ b/backends/webgpu/runtime/ops/sdpa/sdpa_compute_attn_weights_wgsl.h
@@ -13,7 +13,7 @@
 namespace executorch::backends::webgpu {
 
 // @generated from sdpa_compute_attn_weights.wgsl - DO NOT EDIT.
-// wgsl-sha256: e9bdc2272bba2716655e96be0597571701b4ec1496f78a85660e29d108f655f9
+// wgsl-sha256: d177264689e6c50e1794a0599808f3cfe6f30ba99c5084d3c8324da4b9f89d10
 inline constexpr const char* kSdpaComputeAttnWeightsWGSL = R"(
 @group(0) @binding(0) var<storage, read_write> t_attn_weights: array<f32>;
 @group(0) @binding(1) var<storage, read> t_q: array<f32>;
@@ -102,9 +102,11 @@ fn main(@builtin(global_invocation_id) gid: vec3<u32>) {
   acc[2] = vec4<f32>(0.0, 0.0, 0.0, 0.0);
   acc[3] = vec4<f32>(0.0, 0.0, 0.0, 0.0);
 
+  // Skip fully-masked causal tiles; mirrors Vulkan attn_weights_tiled.glsl.
+  let skip_tile = c0 > s0 + (TM - 1u) + params.input_pos;
   var d4: u32 = 0u;
   loop {
-    if (d4 >= params.D) {
+    if (d4 >= params.D || skip_tile) {
       break;
     }
     var q: array<vec4<f32>, TM>;