diff --git a/deps/simdutf/simdutf.cpp b/deps/simdutf/simdutf.cpp
index 376cac3449d1cd..84e4459cf6b97a 100644
--- a/deps/simdutf/simdutf.cpp
+++ b/deps/simdutf/simdutf.cpp
@@ -1,4 +1,4 @@
-/* auto-generated on 2024-04-24 01:28:18 -0400. Do not edit! */
+/* auto-generated on 2024-05-07 22:33:11 -0400. Do not edit! */
 /* begin file src/simdutf.cpp */
 #include "simdutf.h"
 // We include base64_tables once.
@@ -1031,9 +1031,9 @@ namespace {
       return vget_lane_u64(vreinterpret_u64_u8(vshrn_n_u16(vreinterpretq_u16_u8(*this), 4)), 0);
     }
 
-    simdutf_really_inline bool any() const { return vmaxvq_u8(*this) != 0; }
-    simdutf_really_inline bool none() const { return vmaxvq_u8(*this) == 0; }
-    simdutf_really_inline bool all() const { return vminvq_u8(*this) == 0xFF; }
+    simdutf_really_inline bool any() const { return vmaxvq_u32(vreinterpretq_u32_u8(*this)) != 0; }
+    simdutf_really_inline bool none() const { return vmaxvq_u32(vreinterpretq_u32_u8(*this)) == 0; }
+    simdutf_really_inline bool all() const { return vminvq_u32(vreinterpretq_u32_u8(*this)) == 0xFFFFF; }
 
 
   };
@@ -2481,10 +2481,10 @@ namespace simd {
   struct simd8<bool>: base8<bool> {
     static simdutf_really_inline simd8<bool> splat(bool _value) { return _mm256_set1_epi8(uint8_t(-(!!_value))); }
 
-    simdutf_really_inline simd8<bool>() : base8() {}
-    simdutf_really_inline simd8<bool>(const __m256i _value) : base8<bool>(_value) {}
+    simdutf_really_inline simd8() : base8() {}
+    simdutf_really_inline simd8(const __m256i _value) : base8<bool>(_value) {}
     // Splat constructor
-    simdutf_really_inline simd8<bool>(bool _value) : base8<bool>(splat(_value)) {}
+    simdutf_really_inline simd8(bool _value) : base8<bool>(splat(_value)) {}
 
     simdutf_really_inline uint32_t to_bitmask() const { return uint32_t(_mm256_movemask_epi8(*this)); }
     simdutf_really_inline bool any() const { return !_mm256_testz_si256(*this, *this); }
@@ -3409,10 +3409,10 @@ namespace simd {
   struct simd8<bool>: base8<bool> {
     static simdutf_really_inline simd8<bool> splat(bool _value) { return _mm_set1_epi8(uint8_t(-(!!_value))); }
 
-    simdutf_really_inline simd8<bool>() : base8() {}
-    simdutf_really_inline simd8<bool>(const __m128i _value) : base8<bool>(_value) {}
+    simdutf_really_inline simd8() : base8() {}
+    simdutf_really_inline simd8(const __m128i _value) : base8<bool>(_value) {}
     // Splat constructor
-    simdutf_really_inline simd8<bool>(bool _value) : base8<bool>(splat(_value)) {}
+    simdutf_really_inline simd8(bool _value) : base8<bool>(splat(_value)) {}
 
     simdutf_really_inline int to_bitmask() const { return _mm_movemask_epi8(*this); }
     simdutf_really_inline bool any() const { return !_mm_testz_si128(*this, *this); }
@@ -4319,11 +4319,11 @@ template <> struct simd8<bool> : base8<bool> {
     return (__m128i)vec_splats((unsigned char)(-(!!_value)));
   }
 
-  simdutf_really_inline simd8<bool>() : base8() {}
-  simdutf_really_inline simd8<bool>(const __m128i _value)
+  simdutf_really_inline simd8() : base8() {}
+  simdutf_really_inline simd8(const __m128i _value)
       : base8<bool>(_value) {}
   // Splat constructor
-  simdutf_really_inline simd8<bool>(bool _value)
+  simdutf_really_inline simd8(bool _value)
       : base8<bool>(splat(_value)) {}
 
   simdutf_really_inline int to_bitmask() const {
diff --git a/deps/simdutf/simdutf.h b/deps/simdutf/simdutf.h
index da588f100dd432..d37bd2c7db5be8 100644
--- a/deps/simdutf/simdutf.h
+++ b/deps/simdutf/simdutf.h
@@ -1,4 +1,4 @@
-/* auto-generated on 2024-04-24 01:28:18 -0400. Do not edit! */
+/* auto-generated on 2024-05-07 22:33:11 -0400. Do not edit! */
 /* begin file include/simdutf.h */
 #ifndef SIMDUTF_H
 #define SIMDUTF_H
@@ -594,7 +594,7 @@ SIMDUTF_DISABLE_UNDESIRED_WARNINGS
 #define SIMDUTF_SIMDUTF_VERSION_H
 
 /** The version of simdutf being used (major.minor.revision) */
-#define SIMDUTF_VERSION "5.2.6"
+#define SIMDUTF_VERSION "5.2.8"
 
 namespace simdutf {
 enum {
@@ -609,7 +609,7 @@ enum {
   /**
    * The revision (major.minor.REVISION) of simdutf being used.
    */
-  SIMDUTF_VERSION_REVISION = 6
+  SIMDUTF_VERSION_REVISION = 8
 };
 } // namespace simdutf
 
@@ -682,6 +682,17 @@ POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 
+// RISC-V ISA detection utilities
+#if SIMDUTF_IS_RISCV64 && defined(__linux__)
+#include <unistd.h> // for syscall
+// We define these ourselves, for backwards compatibility
+struct simdutf_riscv_hwprobe { int64_t key; uint64_t value; };
+#define simdutf_riscv_hwprobe(...) syscall(258, __VA_ARGS__)
+#define SIMDUTF_RISCV_HWPROBE_KEY_IMA_EXT_0 4
+#define SIMDUTF_RISCV_HWPROBE_IMA_V    (1 << 2)
+#define SIMDUTF_RISCV_HWPROBE_EXT_ZVBB (1 << 17)
+#endif // SIMDUTF_IS_RISCV64 && defined(__linux__)
+
 namespace simdutf {
 namespace internal {
 
@@ -716,17 +727,6 @@ static inline uint32_t detect_supported_architectures() {
 
 #elif SIMDUTF_IS_RISCV64
 
-#if defined(__linux__)
-
-#include <unistd.h>
-// We define these our selfs, for backwards compatibility
-struct simdutf_riscv_hwprobe { int64_t key; uint64_t value; };
-#define simdutf_riscv_hwprobe(...) syscall(258, __VA_ARGS__)
-#define SIMDUTF_RISCV_HWPROBE_KEY_IMA_EXT_0 4
-#define SIMDUTF_RISCV_HWPROBE_IMA_V    (1 << 2)
-#define SIMDUTF_RISCV_HWPROBE_EXT_ZVBB (1 << 17)
-#endif
-
 static inline uint32_t detect_supported_architectures() {
   uint32_t host_isa = instruction_set::DEFAULT;
 #if SIMDUTF_IS_RVV
@@ -2374,7 +2374,7 @@ simdutf_warn_unused size_t base64_length_from_binary(size_t length, base64_optio
  * @param length        the length of the input in bytes
  * @param output        the pointer to buffer that can hold the conversion result (should be at least base64_length_from_binary(length) bytes long)
  * @param options       the base64 options to use, can be base64_default or base64_url, is base64_default by default.
- * @return number of written bytes, will be equal to base64_length_from_binary(length)
+ * @return number of written bytes, will be equal to base64_length_from_binary(length, options)
  */
 size_t binary_to_base64(const char * input, size_t length, char* output, base64_options options = base64_default) noexcept;
 
@@ -3599,7 +3599,7 @@ class implementation {
    * @param length        the length of the input in bytes
    * @param output        the pointer to buffer that can hold the conversion result (should be at least base64_length_from_binary(length) bytes long)
    * @param options       the base64 options to use, can be base64_default or base64_url, is base64_default by default.
-   * @return number of written bytes, will be equal to base64_length_from_binary(length)
+   * @return number of written bytes, will be equal to base64_length_from_binary(length, options)
    */
   virtual size_t binary_to_base64(const char * input, size_t length, char* output, base64_options options = base64_default) const noexcept = 0;