diff --git a/include/eve/module/core/detail/simd/x86/basic_shuffle.hpp b/include/eve/module/core/detail/simd/x86/basic_shuffle.hpp
index a079c60e0a..1015dd71b3 100644
--- a/include/eve/module/core/detail/simd/x86/basic_shuffle.hpp
+++ b/include/eve/module/core/detail/simd/x86/basic_shuffle.hpp
@@ -251,7 +251,7 @@ basic_shuffle_(EVE_SUPPORTS(avx_),
               [](auto i, auto c)
               {
                 Pattern r;
-                return (i < c / 2 ? r(i, c) : r(i - c / 2, c)) << 1;
+                return (r(i,c) % 2) << 1;
               });
 
           auto const m = as_indexes<wide<T, N>>(fixed_pattern);
diff --git a/include/eve/module/core/regular/bit_shr.hpp b/include/eve/module/core/regular/bit_shr.hpp
index 814b5925a3..10316fa80d 100644
--- a/include/eve/module/core/regular/bit_shr.hpp
+++ b/include/eve/module/core/regular/bit_shr.hpp
@@ -15,13 +15,13 @@ namespace eve
   template<typename Options>
   struct bit_shr_t : strict_elementwise_callable<bit_shr_t, Options>
   {
-    template<eve::value T, integral_value S>
-    constexpr EVE_FORCEINLINE  as_wide_as_t<T, S> operator()(T v, S s) const
+    template<integral_value T, integral_value S>
+    constexpr EVE_FORCEINLINE as_wide_as_t<T, S> operator()(T v, S s) const
     { 
       return EVE_DISPATCH_CALL(v, s);
     }
 
-    template<eve::integral_value T, std::ptrdiff_t S>
+    template<integral_value T, std::ptrdiff_t S>
     constexpr EVE_FORCEINLINE T operator()(T v, index_t<S> s) const
     {
       constexpr std::ptrdiff_t l = sizeof(element_type_t<T>) * 8;
diff --git a/include/eve/module/core/regular/bit_swap_pairs.hpp b/include/eve/module/core/regular/bit_swap_pairs.hpp
index f101f9bb87..3449d29622 100644
--- a/include/eve/module/core/regular/bit_swap_pairs.hpp
+++ b/include/eve/module/core/regular/bit_swap_pairs.hpp
@@ -14,7 +14,9 @@
 #include <eve/module/core/regular/bit_cast.hpp>
 #include <eve/module/core/regular/bit_xor.hpp>
 #include <eve/module/core/regular/bit_shl.hpp>
+#include <eve/module/core/regular/convert.hpp>
 #include <eve/module/core/constant/one.hpp>
+#include <eve/traits/max_lanes.hpp>
 
 namespace eve
 {
@@ -22,11 +24,24 @@ namespace eve
   template<typename Options>
   struct bit_swap_pairs_t : strict_elementwise_callable<bit_swap_pairs_t, Options>
   {
-    template<eve::integral_value T, integral_value I0, integral_value I1>
-    constexpr EVE_FORCEINLINE T operator()(T v, I0 i0,  I1 i1) const noexcept
+    template<typename T, typename I0, typename I1>
+    struct result
+    {
+      using type = std::conditional_t<scalar_value<T> && scalar_value<I0> && scalar_value<I1>, T, as_wide_t<T, max_lanes_t<T, I0, I1>>>;
+    };
+
+    template<integral_value T, integral_value I0, integral_value I1>
+    EVE_FORCEINLINE constexpr typename result<T, I0, I1>::type operator()(T v, I0 i0,  I1 i1) const noexcept
+      requires same_lanes_or_scalar<T, I0, I1>
     {
       return EVE_DISPATCH_CALL(v, i0, i1);
     }
+    
+    template<integral_value T, std::ptrdiff_t I0, std::ptrdiff_t I1>
+    EVE_FORCEINLINE constexpr T operator()(T a, index_t<I0> i0, index_t<I1> i1) const noexcept
+    {
+      return EVE_DISPATCH_CALL(a, i0, i1);
+    }
 
     EVE_CALLABLE_OBJECT(bit_swap_pairs_t, bit_swap_pairs_);
   };
@@ -83,16 +98,24 @@ namespace eve
   namespace detail
   {
     template<callable_options O, conditional_expr C, value T, integral_value I0, integral_value I1>
-    constexpr T bit_swap_pairs_(EVE_REQUIRES(cpu_), C const& cx, O const&, T a, I0 i0, I1 i1) noexcept
+    constexpr auto bit_swap_pairs_(EVE_REQUIRES(cpu_), C const& cx, O const&, T a, I0 i0, I1 i1) noexcept
     {
-      auto i0m = if_else(cx, i0, zero);
-      auto i1m = if_else(cx, i1, zero);
+      if constexpr (scalar_value<T> && scalar_value<I0> && scalar_value<I1>)
+      {
+        return bit_swap_pairs(a, cx ? i0 : 0, cx ? i1 : 0);
+      }
+      else
+      {
+        using MC = max_lanes_t<T, I0, I1>;
 
-      return bit_swap_pairs(a, i0m, i1m);
+        auto i0m = if_else(cx, as_wide_t<I0, MC>{i0}, zero);
+        auto i1m = if_else(cx, as_wide_t<I1, MC>{i1}, zero);
+        return bit_swap_pairs(as_wide_t<T, MC>{a}, i0m, i1m);
+      }
     }
 
     template<callable_options O, value T, integral_value I0, integral_value I1>
-    constexpr T bit_swap_pairs_(EVE_REQUIRES(cpu_), O const&, T a, I0 i0, I1 i1) noexcept
+    constexpr auto bit_swap_pairs_(EVE_REQUIRES(cpu_), O const&, T a, I0 i0, I1 i1) noexcept
     {
       // 1 if the bits of a at i0 and i1 are different, 0 otherwise
       auto x = bit_and(
@@ -106,5 +129,13 @@ namespace eve
       // if the bits are different, swap them by toggling both
       return bit_xor(a, bit_shl(x, i1), bit_shl(x, i0));
     }
+
+    template<callable_options O, typename T, std::ptrdiff_t I0, std::ptrdiff_t I1>
+    EVE_FORCEINLINE T bit_swap_pairs_(EVE_REQUIRES(cpu_), O const& o, T x, index_t<I0>, index_t<I1>) noexcept
+    {
+      constexpr std::ptrdiff_t C = sizeof(element_type_t<T>) * 8;
+      static_assert((I0 >= 0) && (I1 >= 0) && (I0 < C) && (I1 < C), "some index(es) are out or range");
+      return bit_swap_pairs[o](x, I0, I1);
+    }
   }
 }
diff --git a/include/eve/module/core/regular/byte_swap_pairs.hpp b/include/eve/module/core/regular/byte_swap_pairs.hpp
index 8df2ab2293..ce535e50bb 100644
--- a/include/eve/module/core/regular/byte_swap_pairs.hpp
+++ b/include/eve/module/core/regular/byte_swap_pairs.hpp
@@ -16,8 +16,10 @@ namespace eve
   struct byte_swap_pairs_t : strict_elementwise_callable<byte_swap_pairs_t, Options>
   {
     template<integral_value T, std::ptrdiff_t I0, std::ptrdiff_t I1>
-    EVE_FORCEINLINE T operator()(T a, index_t<I0> const & i0,  index_t<I1> const & i1) const noexcept
-    { return EVE_DISPATCH_CALL(a, i0, i1); }
+    EVE_FORCEINLINE T operator()(T a, index_t<I0> i0, index_t<I1> i1) const noexcept
+    {
+      return EVE_DISPATCH_CALL(a, i0, i1);
+    }
 
     EVE_CALLABLE_OBJECT(byte_swap_pairs_t, byte_swap_pairs_);
   };
diff --git a/include/eve/module/core/regular/impl/byte_swap_pairs.hpp b/include/eve/module/core/regular/impl/byte_swap_pairs.hpp
index 822a62b763..e124231c47 100644
--- a/include/eve/module/core/regular/impl/byte_swap_pairs.hpp
+++ b/include/eve/module/core/regular/impl/byte_swap_pairs.hpp
@@ -20,11 +20,7 @@
 namespace eve::detail
 {
   template<typename T, std::ptrdiff_t I0, std::ptrdiff_t I1, callable_options O>
-  EVE_FORCEINLINE T byte_swap_pairs_(EVE_REQUIRES(cpu_),
-                                     O const &,
-                                     T x ,
-                                     index_t<I0> const & ,
-                                     index_t<I1> const &) noexcept
+  EVE_FORCEINLINE T byte_swap_pairs_(EVE_REQUIRES(cpu_), O const &, T x, index_t<I0>, index_t<I1>) noexcept
   {
     if constexpr(simd_value<T>)
     {
@@ -54,12 +50,7 @@ namespace eve::detail
 
   // Masked case
   template<conditional_expr C, typename T, std::ptrdiff_t I0, std::ptrdiff_t I1, callable_options O>
-  EVE_FORCEINLINE T byte_swap_pairs_(EVE_REQUIRES(cpu_),
-                                     C const& cond,
-                                     O const &,
-                                     T t,
-                                     index_t<I0> const & i0,
-                                     index_t<I1> const & i1) noexcept
+  EVE_FORCEINLINE T byte_swap_pairs_(EVE_REQUIRES(cpu_), C const& cond, O const&, T t, index_t<I0> i0, index_t<I1> i1) noexcept
   {
     return mask_op(cond, eve::byte_swap_pairs, t, i0, i1);
   }
diff --git a/include/eve/module/core/regular/impl/swap_pairs.hpp b/include/eve/module/core/regular/impl/swap_pairs.hpp
index abc27554f8..1292aec1f4 100644
--- a/include/eve/module/core/regular/impl/swap_pairs.hpp
+++ b/include/eve/module/core/regular/impl/swap_pairs.hpp
@@ -13,24 +13,16 @@
 
 namespace eve::detail
 {
-  template<value T, std::ptrdiff_t I0, std::ptrdiff_t I1>
-  EVE_FORCEINLINE T
-  swap_pairs_(EVE_SUPPORTS(cpu_), T x
-                  , index_t<I0> const &
-                  , index_t<I1> const &  ) noexcept
+  template<callable_options O, simd_value T, std::ptrdiff_t I0, std::ptrdiff_t I1>
+  EVE_FORCEINLINE constexpr T swap_pairs_(EVE_REQUIRES(cpu_), O const&, T x, index_t<I0>, index_t<I1>) noexcept
   {
-    [[maybe_unused]] constexpr std::ptrdiff_t C = scalar_value<T> ? 1 : cardinal_v<T>;
-    EVE_ASSERT((I0 >= 0) && (I1 >= 0) && (I0 < C) && (I1 < C), "some index(es) are out or range");
-    if constexpr(simd_value<T>)
-    {
-      auto p = [](auto i,  auto){
-       return (i == I0) ? I1 :(i == I1 ? I0 : i) ;
-      };
-      return eve::shuffle(x, eve::as_pattern(p));
-    }
-    else if constexpr(scalar_value<T>)
-    {
-      return x;
-    }
+    constexpr std::ptrdiff_t C = cardinal_v<T>;
+    static_assert((I0 >= 0) && (I1 >= 0) && (I0 < C) && (I1 < C), "some index(es) are out or range");
+    
+    auto p = [](auto i,  auto){
+      return (i == I0) ? I1 :(i == I1 ? I0 : i) ;
+    };
+
+    return eve::shuffle(x, eve::as_pattern(p));
   }
 }
diff --git a/include/eve/module/core/regular/swap_pairs.hpp b/include/eve/module/core/regular/swap_pairs.hpp
index 84b8aab770..2f78108534 100644
--- a/include/eve/module/core/regular/swap_pairs.hpp
+++ b/include/eve/module/core/regular/swap_pairs.hpp
@@ -11,47 +11,57 @@
 
 namespace eve
 {
-//TODO DOC
-//================================================================================================
-//! @addtogroup core_bitops
-//! @{
-//!   @var swap_pairs
-//!   @brief swap chosen pair of elements.
-//!
-//!   @groupheader{Header file}
-//!
-//!   @code
-//!   #include <eve/module/core.hpp>
-//!   @endcode
-//!
-//!   @groupheader{Callable Signatures}
-//!
-//!   @code
-//!   namespace eve
-//!   {
-//!      template<value T, std::ptrdiff_t I0, std::ptrdiff_t I1 >
-//!      T swap_pairs(T x, index_t<I0> const & i0, index_t<I1> const & i1);
-//!   @endcode
-//!
-//!   **Parameters**
-//!
-//!     * `x` :  [argument](@ref eve::value).
-//!     * `i0` : first index
-//!     * `i1` : second index
-//!
-//!    **Return value**
-//!
-//!    Return x with element i0 and i1 swapped. Action on scalar is identity.
-//!    Assert if i0 or i1 are out of range.
-//!
-//!  @groupheader{Example}
-//!
-//!  @godbolt{doc/core/swap_pairs.cpp}
-//================================================================================================
-EVE_MAKE_CALLABLE(swap_pairs_, swap_pairs);
-//================================================================================================
-//! @}
-//================================================================================================
+  template<typename Options>
+  struct swap_pairs_t : callable<swap_pairs_t, Options>
+  {
+    template<simd_value T, std::ptrdiff_t I0, std::ptrdiff_t I1>
+    EVE_FORCEINLINE T operator()(T x, index_t<I0> i0, index_t<I1> i1) const noexcept
+    {
+      return EVE_DISPATCH_CALL(x, i0, i1);
+    }
+
+    EVE_CALLABLE_OBJECT(swap_pairs_t, swap_pairs_);
+  };
+
+  //================================================================================================
+  //! @addtogroup core_bitops
+  //! @{
+  //!   @var swap_pairs
+  //!   @brief swap chosen pair of elements.
+  //!
+  //!   @groupheader{Header file}
+  //!
+  //!   @code
+  //!   #include <eve/module/core.hpp>
+  //!   @endcode
+  //!
+  //!   @groupheader{Callable Signatures}
+  //!
+  //!   @code
+  //!   namespace eve
+  //!   {
+  //!      template<simd_value T, std::ptrdiff_t I0, std::ptrdiff_t I1 >
+  //!      T swap_pairs(T x, index_t<I0> i0, index_t<I1> i1);
+  //!   @endcode
+  //!
+  //!   **Parameters**
+  //!
+  //!     * `x` :  [argument](@ref eve::simd_value).
+  //!     * `i0` : first index
+  //!     * `i1` : second index
+  //!
+  //!    **Return value**
+  //!
+  //!    Return x with element i0 and i1 swapped.
+  //!
+  //!  @groupheader{Example}
+  //!
+  //!  @godbolt{doc/core/swap_pairs.cpp}
+  //================================================================================================
+  inline constexpr auto swap_pairs = functor<swap_pairs_t>;
+  //================================================================================================
+  //! @}
+  //================================================================================================
 }
 
 #include <eve/module/core/regular/impl/swap_pairs.hpp>
diff --git a/include/eve/traits/max_lanes.hpp b/include/eve/traits/max_lanes.hpp
new file mode 100644
index 0000000000..6566e65c84
--- /dev/null
+++ b/include/eve/traits/max_lanes.hpp
@@ -0,0 +1,51 @@
+//==================================================================================================
+/*
+  EVE - Expressive Vector Engine
+  Copyright : EVE Project Contributors
+  SPDX-License-Identifier: BSL-1.0
+*/
+//==================================================================================================
+#pragma once
+
+namespace eve
+{
+  namespace detail
+  {
+    template<typename... Ts>
+    consteval auto compute_max_lanes()
+    {
+      std::ptrdiff_t cards[] = { cardinal_v<Ts>... };
+
+      auto max_card = cards[0];
+      for(auto c : cards) max_card = max_card < c ? c : max_card;
+
+      return max_card;
+    }
+  }
+
+  //================================================================================================
+  //! @addtogroup traits
+  //! @{
+  //!  @var max_lanes
+  //!
+  //!  @tparam Ts Types to process
+  //!
+  //!  @brief A meta function for getting a maximum lane count of given wide or scalar types.
+  //! @}
+  //================================================================================================
+  template <typename... Ts>
+  inline constexpr auto max_lanes_v = detail::compute_max_lanes<Ts...>();
+
+  //================================================================================================
+  //! @addtogroup traits
+  //! @{
+  //!  @var max_lanes
+  //!
+  //!  @tparam Ts Types to process
+  //!
+  //!  @brief The cardinal type of the maximum lane count of given wide or scalar types.
+  //! @}
+  //================================================================================================
+  template <typename... Ts>
+  using max_lanes_t = fixed<max_lanes_v<Ts...>>; 
+}
diff --git a/test/doc/core/bit_swap_pairs.cpp b/test/doc/core/bit_swap_pairs.cpp
index dca51044cb..15cb98e399 100644
--- a/test/doc/core/bit_swap_pairs.cpp
+++ b/test/doc/core/bit_swap_pairs.cpp
@@ -12,9 +12,19 @@ int main()
   std::cout << std::showbase << std::hex;
   std::cout << "<- wi0                                           = " << wi0 << "\n";
   std::cout << "<- wi1                                           = " << wi1 << "\n";
-  std::cout << "<- wi2                                           = " << wi2 << "\n";
+  std::cout << "<- wi2                                           = " << wi2 << "\n\n";
                                                                  
   std::cout << "-> bit_swap_pairs(wi0, wi1, wi2)                 = " << eve::bit_swap_pairs(wi0, wi1, wi2) << "\n";
   std::cout << "-> bit_swap_pairs[ignore_last(2)](wi0, wi1, wi2) = " << eve::bit_swap_pairs[eve::ignore_last(2)](wi0, wi1, wi2) << "\n";
-  std::cout << "-> bit_swap_pairs[wi3 > 0](wi0, wi1, wi3)        = " << eve::bit_swap_pairs[wi3 >= 0](wi0, wi1, wi3) << "\n";
+  std::cout << "-> bit_swap_pairs[wi3 > 0](wi0, wi1, wi3)        = " << eve::bit_swap_pairs[wi3 >= 0](wi0, wi1, wi3) << "\n\n";
+
+  std::cout << "-> bit_swap_pairs(wi0, 3, 2)                 = " << eve::bit_swap_pairs(wi0, 3, 2) << "\n";
+  std::cout << "-> bit_swap_pairs[ignore_last(2)](wi0, 3, 2) = " << eve::bit_swap_pairs[eve::ignore_last(2)](wi0, 3, 2) << "\n";
+  std::cout << "-> bit_swap_pairs[wi3 > 0](wi0, 3, 2)        = " << eve::bit_swap_pairs[wi3 >= 0](wi0, 3, 2) << "\n\n";
+
+  auto i3 = eve::index_t<3>{};
+  auto i2 = eve::index_t<2>{};
+  std::cout << "-> bit_swap_pairs(wi0, i3, i2)                 = " << eve::bit_swap_pairs(wi0, i3, i2) << "\n";
+  std::cout << "-> bit_swap_pairs[ignore_last(2)](wi0, i3, i2) = " << eve::bit_swap_pairs[eve::ignore_last(2)](wi0, i3, i2) << "\n";
+  std::cout << "-> bit_swap_pairs[wi3 > 0](wi0, i3, i2)        = " << eve::bit_swap_pairs[wi3 >= 0](wi0, i3, i2) << "\n\n";
 }
diff --git a/test/unit/module/core/bit_swap_pairs.cpp b/test/unit/module/core/bit_swap_pairs.cpp
index 49c3d52729..4663466ae2 100644
--- a/test/unit/module/core/bit_swap_pairs.cpp
+++ b/test/unit/module/core/bit_swap_pairs.cpp
@@ -20,8 +20,21 @@ TTS_CASE_WITH("Check behavior of bit_swap_pairs(simd) on integral types",
   using v_t = eve::element_type_t<T>;
   using eve::bit_swap_pairs;
 
-  TTS_EQUAL(bit_swap_pairs(a0, 0u, 7u), tts::map([](auto e) -> v_t { return eve::bit_swap_pairs(e, 0u, 7u); }, a0)) << a0 << '\n';
-  TTS_EQUAL(eve::bit_swap_pairs[t](a0, 0u, 7u), eve::if_else(t, eve::bit_swap_pairs(a0, 0u, 7u), a0));
+  // full scalar
+  TTS_EQUAL(eve::bit_swap_pairs(0b01010101, 0, 7), 0b11010100);
+  TTS_EQUAL(eve::bit_swap_pairs(0b01010101, eve::index<0>, eve::index<7>), 0b11010100);
+
+  // scalar into wide
+  using wt = eve::wide<int, eve::fixed<4>>;
+  TTS_EQUAL(eve::bit_swap_pairs(0b01010101, wt{0}, wt{7}), wt{0b11010100});
+
+  // wide
+  TTS_EQUAL(bit_swap_pairs(a0, 0u, 7), tts::map([](auto e) -> v_t { return eve::bit_swap_pairs(e, 0, 7u); }, a0)) << a0 << '\n';
+  TTS_EQUAL(bit_swap_pairs(a0, eve::index<0>, eve::index<7>), tts::map([](auto e) -> v_t { return eve::bit_swap_pairs(e, eve::index<0>, eve::index<7>); }, a0)) << a0 << '\n';
+  
+  // wide masked
+  TTS_EQUAL(eve::bit_swap_pairs[t](a0, 0u, 7), eve::if_else(t, eve::bit_swap_pairs(a0, 0, 7u), a0));
+  TTS_EQUAL(eve::bit_swap_pairs[t](a0, eve::index<0>, eve::index<7>), eve::if_else(t, eve::bit_swap_pairs(a0, eve::index<0>, eve::index<7>), a0));
 
   eve::wide<int, typename T::cardinal_type> wn{[](auto i, auto) { return -i; }};
   TTS_EQUAL(eve::bit_swap_pairs[wn > 0](a0, wn, 7), a0);
diff --git a/test/unit/module/core/swap_pairs.cpp b/test/unit/module/core/swap_pairs.cpp
index 7057be5ce8..80a8b116cc 100644
--- a/test/unit/module/core/swap_pairs.cpp
+++ b/test/unit/module/core/swap_pairs.cpp
@@ -13,17 +13,19 @@
 //==================================================================================================
 TTS_CASE_WITH("Check behavior of swap_pairs(simd) on all types",
               eve::test::simd::all_types,
-              tts::generate(tts::randoms(eve::valmin, eve::valmax)
-                           )
+              tts::generate(tts::randoms(eve::valmin, eve::valmax))
              )
 <typename T>(T const& a0)
 {
-  using v_t = eve::element_type_t<T>;
   using eve::swap_pairs;
-  constexpr size_t S =  eve::cardinal_v<v_t>-1;
+  constexpr size_t S =  eve::cardinal_v<T> - 1;
   constexpr auto _0 = eve::index_t<0>();
   constexpr auto _S = eve::index_t<S>();
   constexpr auto _H = eve::index_t<S/2>();
-  TTS_EQUAL(swap_pairs(a0, _0, _S), tts::map([_0, _S](auto e) -> v_t { return swap_pairs(e, _0, _S); }, a0));
-  TTS_EQUAL(swap_pairs(a0, _0, _H), tts::map([_0, _H](auto e) -> v_t { return swap_pairs(e, _0, _H); }, a0));
+
+  T refS = [&](auto i, auto) { return i == 0 ? a0.get(S) : (i == S ? a0.get(0) : a0.get(i)); };
+  T refH = [&](auto i, auto) { return i == 0 ? a0.get(S/2) : (i == S/2 ? a0.get(0) : a0.get(i)); };
+
+  TTS_EQUAL(swap_pairs(a0, _0, _S), refS);
+  TTS_EQUAL(swap_pairs(a0, _0, _H), refH);
 };