diff --git a/src/passes/CMakeLists.txt b/src/passes/CMakeLists.txt
index a763006ab66..f604c7ba921 100644
--- a/src/passes/CMakeLists.txt
+++ b/src/passes/CMakeLists.txt
@@ -106,6 +106,7 @@ set(passes_SOURCES
   RemoveImports.cpp
   RemoveMemoryInit.cpp
   RemoveNonJSOps.cpp
+  RemoveRelaxedSIMD.cpp
   RemoveUnusedBrs.cpp
   RemoveUnusedNames.cpp
   RemoveUnusedModuleElements.cpp
diff --git a/src/passes/RemoveRelaxedSIMD.cpp b/src/passes/RemoveRelaxedSIMD.cpp
new file mode 100644
index 00000000000..5dfd82ecd70
--- /dev/null
+++ b/src/passes/RemoveRelaxedSIMD.cpp
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2026 WebAssembly Community Group participants
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//
+// Replaces relaxed SIMD instructions with traps.
+//
+
+#include <memory>
+
+#include "ir/localize.h"
+#include "ir/utils.h"
+#include "pass.h"
+#include "wasm-builder.h"
+#include "wasm.h"
+
+namespace wasm {
+
+struct RemoveRelaxedSIMD : WalkerPass<PostWalker<RemoveRelaxedSIMD>> {
+  bool isFunctionParallel() override { return true; }
+
+  std::unique_ptr<Pass> create() override {
+    return std::make_unique<RemoveRelaxedSIMD>();
+  }
+
+  void replace(Expression* curr) {
+    auto* block =
+      ChildLocalizer(curr, getFunction(), *getModule(), getPassOptions())
+        .getChildrenReplacement();
+    block->list.push_back(Builder(*getModule()).makeUnreachable());
+    replaceCurrent(block);
+  }
+
+  void visitUnary(Unary* curr) {
+    switch (curr->op) {
+      case RelaxedTruncSVecF32x4ToVecI32x4:
+      case RelaxedTruncUVecF32x4ToVecI32x4:
+      case RelaxedTruncZeroSVecF64x2ToVecI32x4:
+      case RelaxedTruncZeroUVecF64x2ToVecI32x4:
+        replace(curr);
+        return;
+      default:
+        break;
+    }
+  }
+
+  void visitBinary(Binary* curr) {
+    switch (curr->op) {
+      case RelaxedSwizzleVecI8x16:
+      case RelaxedMinVecF32x4:
+      case RelaxedMaxVecF32x4:
+      case RelaxedMinVecF64x2:
+      case RelaxedMaxVecF64x2:
+      case RelaxedQ15MulrSVecI16x8:
+      case DotI8x16I7x16SToVecI16x8:
+        replace(curr);
+        return;
+      default:
+        break;
+    }
+  }
+
+  void visitSIMDTernary(SIMDTernary* curr) {
+    switch (curr->op) {
+      case RelaxedMaddVecF16x8:
+      case RelaxedNmaddVecF16x8:
+      case RelaxedMaddVecF32x4:
+      case RelaxedNmaddVecF32x4:
+      case RelaxedMaddVecF64x2:
+      case RelaxedNmaddVecF64x2:
+      case LaneselectI8x16:
+      case LaneselectI16x8:
+      case LaneselectI32x4:
+      case LaneselectI64x2:
+      case DotI8x16I7x16AddSToVecI32x4:
+        replace(curr);
+        return;
+      default:
+        break;
+    }
+  }
+
+  void visitFunction(Function* func) {
+    ReFinalize().walkFunctionInModule(func, getModule());
+  }
+};
+
+Pass* createRemoveRelaxedSIMDPass() { return new RemoveRelaxedSIMD(); }
+
+} // namespace wasm
diff --git a/src/passes/pass.cpp b/src/passes/pass.cpp
index 0f83013b8ab..dd49609c378 100644
--- a/src/passes/pass.cpp
+++ b/src/passes/pass.cpp
@@ -408,6 +408,9 @@ void PassRegistry::registerPasses() {
   registerPass("remove-non-js-ops",
                "removes operations incompatible with js",
                createRemoveNonJSOpsPass);
+  registerPass("remove-relaxed-simd",
+               "replaces relaxed SIMD instructions with unreachable",
+               createRemoveRelaxedSIMDPass);
   registerPass("remove-imports",
                "removes imports and replaces them with nops",
                createRemoveImportsPass);
diff --git a/src/passes/passes.h b/src/passes/passes.h
index 6481e062c6d..208b4f803e0 100644
--- a/src/passes/passes.h
+++ b/src/passes/passes.h
@@ -133,6 +133,7 @@ Pass* createPrintFunctionMapPass();
 Pass* createPropagateGlobalsGloballyPass();
 Pass* createRandomizeBranchHintsPass();
 Pass* createRemoveNonJSOpsPass();
+Pass* createRemoveRelaxedSIMDPass();
 Pass* createRemoveImportsPass();
 Pass* createRemoveMemoryInitPass();
 Pass* createRemoveUnusedBrsPass();
diff --git a/test/lit/help/wasm-metadce.test b/test/lit/help/wasm-metadce.test
index 98785fda862..b566afd8471 100644
--- a/test/lit/help/wasm-metadce.test
+++ b/test/lit/help/wasm-metadce.test
@@ -391,6 +391,9 @@
 ;; CHECK-NEXT:   --remove-non-js-ops                           removes operations incompatible
 ;; CHECK-NEXT:                                                 with js
 ;; CHECK-NEXT:
+;; CHECK-NEXT:   --remove-relaxed-simd                         replaces relaxed SIMD
+;; CHECK-NEXT:                                                 instructions with unreachable
+;; CHECK-NEXT:
 ;; CHECK-NEXT:   --remove-unused-brs                           removes breaks from locations
 ;; CHECK-NEXT:                                                 that are not needed
 ;; CHECK-NEXT:
diff --git a/test/lit/help/wasm-opt.test b/test/lit/help/wasm-opt.test
index 4c0f4f67047..eff3724891c 100644
--- a/test/lit/help/wasm-opt.test
+++ b/test/lit/help/wasm-opt.test
@@ -423,6 +423,9 @@
 ;; CHECK-NEXT:   --remove-non-js-ops                           removes operations incompatible
 ;; CHECK-NEXT:                                                 with js
 ;; CHECK-NEXT:
+;; CHECK-NEXT:   --remove-relaxed-simd                         replaces relaxed SIMD
+;; CHECK-NEXT:                                                 instructions with unreachable
+;; CHECK-NEXT:
 ;; CHECK-NEXT:   --remove-unused-brs                           removes breaks from locations
 ;; CHECK-NEXT:                                                 that are not needed
 ;; CHECK-NEXT:
diff --git a/test/lit/help/wasm2js.test b/test/lit/help/wasm2js.test
index 3c201f79ac4..cd55ac22235 100644
--- a/test/lit/help/wasm2js.test
+++ b/test/lit/help/wasm2js.test
@@ -355,6 +355,9 @@
 ;; CHECK-NEXT:   --remove-non-js-ops                           removes operations incompatible
 ;; CHECK-NEXT:                                                 with js
 ;; CHECK-NEXT:
+;; CHECK-NEXT:   --remove-relaxed-simd                         replaces relaxed SIMD
+;; CHECK-NEXT:                                                 instructions with unreachable
+;; CHECK-NEXT:
 ;; CHECK-NEXT:   --remove-unused-brs                           removes breaks from locations
 ;; CHECK-NEXT:                                                 that are not needed
 ;; CHECK-NEXT:
diff --git a/test/lit/passes/remove-relaxed-simd.wast b/test/lit/passes/remove-relaxed-simd.wast
new file mode 100644
index 00000000000..2269aedc4d2
--- /dev/null
+++ b/test/lit/passes/remove-relaxed-simd.wast
@@ -0,0 +1,207 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py and should not be edited.
+
+;; RUN: wasm-opt %s -all --remove-relaxed-simd -S -o - | filecheck %s
+
+(module
+  ;; CHECK:      (import "" "" (func $effect (type $1) (result v128)))
+  (import "" "" (func $effect (result v128)))
+  ;; CHECK:      (func $unary (type $0) (param $0 v128)
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (v128.not
+  ;; CHECK-NEXT:    (local.get $0)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $unary (param v128)
+    (drop (i32x4.relaxed_trunc_f32x4_s (local.get 0)))
+    (drop (i32x4.relaxed_trunc_f32x4_u (local.get 0)))
+    (drop (i32x4.relaxed_trunc_f64x2_s_zero (local.get 0)))
+    (drop (i32x4.relaxed_trunc_f64x2_u_zero (local.get 0)))
+    ;; Normal SIMD instruction
+    (drop (v128.not (local.get 0)))
+  )
+
+  ;; CHECK:      (func $binary (type $2) (param $0 v128) (param $1 v128)
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (v128.xor
+  ;; CHECK-NEXT:    (local.get $0)
+  ;; CHECK-NEXT:    (local.get $1)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $binary (param v128 v128)
+    (drop (i8x16.relaxed_swizzle (local.get 0) (local.get 1)))
+    (drop (f32x4.relaxed_min (local.get 0) (local.get 1)))
+    (drop (f32x4.relaxed_max (local.get 0) (local.get 1)))
+    (drop (f64x2.relaxed_min (local.get 0) (local.get 1)))
+    (drop (f64x2.relaxed_max (local.get 0) (local.get 1)))
+    (drop (i16x8.relaxed_q15mulr_s (local.get 0) (local.get 1)))
+    (drop (i16x8.dot_i8x16_i7x16_s (local.get 0) (local.get 1)))
+    ;; Normal SIMD instruction
+    (drop (v128.xor (local.get 0) (local.get 1)))
+  )
+
+  ;; CHECK:      (func $ternary (type $3) (param $0 v128) (param $1 v128) (param $2 v128)
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (v128.bitselect
+  ;; CHECK-NEXT:    (local.get $0)
+  ;; CHECK-NEXT:    (local.get $1)
+  ;; CHECK-NEXT:    (local.get $2)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $ternary (param v128 v128 v128)
+    (drop (i32x4.dot_i8x16_i7x16_add_s (local.get 0) (local.get 1) (local.get 2)))
+    (drop (f16x8.relaxed_madd (local.get 0) (local.get 1) (local.get 2)))
+    (drop (f16x8.relaxed_nmadd (local.get 0) (local.get 1) (local.get 2)))
+    (drop (f32x4.relaxed_madd (local.get 0) (local.get 1) (local.get 2)))
+    (drop (f32x4.relaxed_nmadd (local.get 0) (local.get 1) (local.get 2)))
+    (drop (f64x2.relaxed_madd (local.get 0) (local.get 1) (local.get 2)))
+    (drop (f64x2.relaxed_nmadd (local.get 0) (local.get 1) (local.get 2)))
+    ;; Normal SIMD instruction
+    (drop (v128.bitselect (local.get 0) (local.get 1) (local.get 2)))
+  )
+
+  ;; CHECK:      (func $refinalize (type $0) (param $0 v128)
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block $l
+  ;; CHECK-NEXT:    (block
+  ;; CHECK-NEXT:     (unreachable)
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $refinalize (param v128)
+    (drop
+      ;; This block should become unreachable.
+      (block $l (result v128)
+        (i32x4.relaxed_trunc_f32x4_s (local.get 0))
+      )
+    )
+  )
+
+  ;; CHECK:      (func $effects (type $0) (param $0 v128)
+  ;; CHECK-NEXT:  (local $1 v128)
+  ;; CHECK-NEXT:  (local $2 v128)
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (block
+  ;; CHECK-NEXT:    (local.set $1
+  ;; CHECK-NEXT:     (call $effect)
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:    (local.set $2
+  ;; CHECK-NEXT:     (block (result v128)
+  ;; CHECK-NEXT:      (drop
+  ;; CHECK-NEXT:       (call $effect)
+  ;; CHECK-NEXT:      )
+  ;; CHECK-NEXT:      (local.get $0)
+  ;; CHECK-NEXT:     )
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:    (unreachable)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $effects (param v128)
+    (drop
+      (f16x8.relaxed_madd
+        (call $effect)
+        (local.get 0)
+        (block (result v128)
+          (drop
+            (call $effect)
+          )
+          (local.get 0)
+        )
+      )
+    )
+  )
+)