diff --git a/Hashes.h b/Hashes.h
index e6988dc5..b2dbe53d 100644
--- a/Hashes.h
+++ b/Hashes.h
@@ -628,6 +628,17 @@ inline void wyhash32low (const void * key, int len, uint32_t seed, void * out) {
 }
 #endif
 
+#ifdef HAVE_INT64
+#include "rapidhash.h"
+inline void rapidhash_test (const void * key, int len, uint32_t seed, void * out) {
+  *(uint64_t*)out = rapidhash_withSeed_compact(key, (uint64_t)len, (uint64_t)seed);
+}
+
+inline void rapidhash_unrolled_test (const void * key, int len, uint32_t seed, void * out) {
+  *(uint64_t*)out = rapidhash_withSeed_unrolled(key, (uint64_t)len, (uint64_t)seed);
+}
+#endif
+
 #ifdef HAVE_INT64
 #include "o1hash.h"
 // unseeded. objsize: 101
diff --git a/main.cpp b/main.cpp
index 2d24b83b..eeb920ae 100644
--- a/main.cpp
+++ b/main.cpp
@@ -747,6 +747,10 @@ HashInfo g_hashes[] =
   {0x1443cf9a, 0x2ae375a2, 0x729973d2, 0x72d3aa79, 0xd3e475d5} },
 { wyhash_test,          64, 0x9DAE7DD3, "wyhash", "wyhash v4.2 (64-bit)", GOOD, {}},
 #endif
+#ifdef HAVE_INT64
+{ rapidhash_test,          64, 0xAF404C4B, "rapidhash", "rapidhash v1", GOOD, {}},
+{ rapidhash_unrolled_test,          64, 0xAF404C4B, "rapidhash_unrolled", "rapidhash v1 - unrolled", GOOD, {}},
+#endif
 { nmhash32_test,        32, 0x12A30553, "nmhash32",       "nmhash32", GOOD, {}},
 { nmhash32x_test,       32, 0xA8580227, "nmhash32x",      "nmhash32x", GOOD, {}},
 #ifdef HAVE_KHASHV
diff --git a/rapidhash.h b/rapidhash.h
new file mode 100755
index 00000000..97225305
--- /dev/null
+++ b/rapidhash.h
@@ -0,0 +1,302 @@
+/*
+ * rapidhash - Very fast, high quality, platform independant hashing algorithm.
+ * Copyright (C) 2024 Nicolas De Carli
+ *
+ * Based on 'wyhash', by Wang Yi <godspeed_china@yeah.net>
+ *
+ * BSD 2-Clause License (https://www.opensource.org/licenses/bsd-license.php)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above
+ *      copyright notice, this list of conditions and the following disclaimer
+ *      in the documentation and/or other materials provided with the
+ *      distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * You can contact the author at:
+ *   - rapidhash source repository: https://github.com/Nicoshev/rapidhash
+ */
+
+/*
+ *  Includes
+ */
+#include <stdint.h>
+#include <string.h>
+#if defined(_MSC_VER)
+  #include <intrin.h>
+  #if defined(_M_X64) && !defined(_M_ARM64EC)
+    #pragma intrinsic(_umul128)
+  #endif
+#endif
+
+/*
+ *  Protection macro, alters behaviour of rapid_mum multiplication function.
+ *  
+ *  RAPIDHASH_FAST: Normal behavior, max speed.
+ *  RAPIDHASH_PROTECTED: Extra protection against entropy loss.
+ */
+#ifndef RAPIDHASH_PROTECTED
+  #define RAPIDHASH_FAST
+#elif defined(RAPIDHASH_FAST)
+  #error "cannot define RAPIDHASH_PROTECTED and RAPIDHASH_FAST simultaneously."
+#endif
+
+/*
+ *  Likely and unlikely macros
+ */
+#if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__)
+  #define _likely_(x)  __builtin_expect(x,1)
+  #define _unlikely_(x)  __builtin_expect(x,0)
+#else
+  #define _likely_(x) (x)
+  #define _unlikely_(x) (x)
+#endif
+
+/*
+ *  Endianness macros
+ */
+#ifndef RAPIDHASH_LITTLE_ENDIAN
+  #if defined(_WIN32) || defined(__LITTLE_ENDIAN__) || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+    #define RAPIDHASH_LITTLE_ENDIAN 1
+  #elif defined(__BIG_ENDIAN__) || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+    #define RAPIDHASH_LITTLE_ENDIAN 0
+  #else
+    #warning could not determine endianness! Falling back to little endian.
+    #define RAPIDHASH_LITTLE_ENDIAN 1
+  #endif
+#endif
+
+/*
+ *  Default seed.
+ */
+#define RAPID_SEED (0xbdd89aa982704029ull)
+
+/*
+ *  Default secret parameters.
+ */
+static const uint64_t rapid_secret[3] = {0x2d358dccaa6c78a5ull, 0x8bb84b93962eacc9ull, 0x4b33a62ed433d4a3ull};
+
+/*
+ *  64*64 -> 128bit multiply function
+ *  
+ *  @param A  Address of 64-bit number.
+ *  @param B  Address of 64-bit number.
+ *
+ *  Calculates 128-bit C = A * B.
+ *
+ *  When RAPIDHASH_PROTECTION==0:
+ *  Overwritres A contents with C's low 64 bits.
+ *  Overwritres B contents with C's high 64 bits.
+ *
+ *  When RAPIDHASH_PROTECTION>0:
+ *  Xors and overwrites A contents with C's low 64 bits.
+ *  Xors and overwrites B contents with C's high 64 bits.
+ *
+ */
+static inline void rapid_mum(uint64_t *A, uint64_t *B){
+#if defined(__SIZEOF_INT128__)
+  __uint128_t r=*A; r*=*B; 
+  #if(RAPIDHASH_PROTECTED)
+  *A^=(uint64_t)r; *B^=(uint64_t)(r>>64);
+  #else
+  *A=(uint64_t)r; *B=(uint64_t)(r>>64);
+  #endif
+#elif defined(_MSC_VER) && (defined(_WIN64) || defined(_M_HYBRID_CHPE_ARM64))
+  #if defined(_M_X64)
+    #if(RAPIDHASH_PROTECTED)
+    uint64_t  a,  b;
+    a=_umul128(*A,*B,&b);
+    *A^=a;  *B^=b;
+    #else
+    *A=_umul128(*A,*B,B);
+    #endif
+  #else
+    #if(RAPIDHASH_PROTECTED)
+    uint64_t a, b;
+    b = __umulh(*A, *B);
+    a = *A * *B;
+    *A^=a;  *B^=b;
+    #else
+    uint64_t c;
+    c = __umulh(*A, *B);
+    *A = *A * *B;
+    *B = c;
+    #endif
+  #endif
+#else
+  uint64_t ha=*A>>32, hb=*B>>32, la=(uint32_t)*A, lb=(uint32_t)*B, hi, lo;
+  uint64_t rh=ha*hb, rm0=ha*lb, rm1=hb*la, rl=la*lb, t=rl+(rm0<<32), c=t<rl;
+  lo=t+(rm1<<32); c+=lo<t; hi=rh+(rm0>>32)+(rm1>>32)+c;
+  #if(RAPIDHASH_PROTECTED)
+  *A^=lo;  *B^=hi;
+  #else
+  *A=lo;  *B=hi;
+  #endif
+#endif
+}
+
+/*
+ *  Multiply and xor mix function.
+ *  
+ *  @param A  64-bit number.
+ *  @param B  64-bit number.
+ *
+ *  Calculates 128-bit C = A * B.
+ *  Returns 64-bit xor between high and low 64 bits of C.
+ */
+static inline uint64_t rapid_mix(uint64_t A, uint64_t B){ rapid_mum(&A,&B); return A^B; }
+
+/*
+ *  Read functions.
+ */
+#if (RAPIDHASH_LITTLE_ENDIAN)
+static inline uint64_t rapid_read64(const uint8_t *p) { uint64_t v; memcpy(&v, p, 8); return v;}
+static inline uint64_t rapid_read32(const uint8_t *p) { uint32_t v; memcpy(&v, p, 4); return v;}
+#elif defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__)
+static inline uint64_t rapid_read64(const uint8_t *p) { uint64_t v; memcpy(&v, p, 8); return __builtin_bswap64(v);}
+static inline uint64_t rapid_read32(const uint8_t *p) { uint32_t v; memcpy(&v, p, 4); return __builtin_bswap32(v);}
+#elif defined(_MSC_VER)
+static inline uint64_t rapid_read64(const uint8_t *p) { uint64_t v; memcpy(&v, p, 8); return _byteswap_uint64(v);}
+static inline uint64_t rapid_read32(const uint8_t *p) { uint32_t v; memcpy(&v, p, 4); return _byteswap_ulong(v);}
+#else
+static inline uint64_t rapid_read64(const uint8_t *p) {
+  uint64_t v; memcpy(&v, p, 8);
+  return (((v >> 56) & 0xff)| ((v >> 40) & 0xff00)| ((v >> 24) & 0xff0000)| ((v >>  8) & 0xff000000)| ((v <<  8) & 0xff00000000)| ((v << 24) & 0xff0000000000)| ((v << 40) & 0xff000000000000)| ((v << 56) & 0xff00000000000000));
+}
+static inline uint64_t rapid_read32(const uint8_t *p) {
+  uint32_t v; memcpy(&v, p, 4);
+  return (((v >> 24) & 0xff)| ((v >>  8) & 0xff00)| ((v <<  8) & 0xff0000)| ((v << 24) & 0xff000000));
+}
+#endif
+
+/*
+ *  Reads and combines 3 bytes of input.
+ *
+ *  @param p  Buffer to read from.
+ *  @param k  Length of @p, in bytes.
+ *
+ *  Always reads and combines 3 bytes from memory.
+ *  Guarantees to read each buffer position at least once.
+ *  
+ *  Returns a 64-bit value contaning all three bytes read. 
+ */
+static inline uint64_t rapid_readSmall(const uint8_t *p, size_t k) { return (((uint64_t)p[0])<<56)|(((uint64_t)p[k>>1])<<32)|p[k-1];}
+
+#define rapidhash_internal_prologue \
+const uint8_t *p=(const uint8_t *)key; seed^=rapid_mix(seed^secret[0],secret[1])^len;  uint64_t  a,  b;\
+  if(_likely_(len<=16)){\
+    if(_likely_(len>=4)){\
+      const uint8_t * plast = p + len - 4;\
+      a = (rapid_read32(p) << 32) | rapid_read32(plast);\
+      const uint64_t delta = ((len&24)>>(len>>3));\
+      b = ((rapid_read32(p + delta) << 32) | rapid_read32(plast - delta)); }\
+    else if(_likely_(len>0)){ a=rapid_readSmall(p,len); b=0;}\
+    else a=b=0;\
+  }\
+  else{\
+    size_t i=len;\
+    if(_unlikely_(i>48)){\
+      uint64_t see1=seed, see2=seed;
+
+#define rapidhash_internal_epilogue \
+    seed^=see1^see2;\
+    }\
+    if(i>16){\
+      seed=rapid_mix(rapid_read64(p)^secret[2],rapid_read64(p+8)^seed^secret[1]);\
+      if(i>32)\
+        seed=rapid_mix(rapid_read64(p+16)^secret[2],rapid_read64(p+24)^seed);\
+    }\
+    a=rapid_read64(p+i-16);  b=rapid_read64(p+i-8);\
+  }\
+  a^=secret[1]; b^=seed;  rapid_mum(&a,&b);\
+  return  rapid_mix(a^secret[0]^len,b^secret[1]);
+
+/*
+ *  rapidhash main function
+ *
+ *  @param key     Buffer to be hashed.
+ *  @param len     @key length, in bytes.
+ *  @param seed    64-bit seed used to alter the hash result predictably.
+ *  @param secret  Triplet of 64-bit secrets used to alter hash result predictably.
+ *
+ *  Returns a 64-bit hash.
+ */
+static inline uint64_t rapidhash_internal_compact(const void *key, size_t len, uint64_t seed, const uint64_t* secret){
+  rapidhash_internal_prologue
+  do {
+    seed=rapid_mix(rapid_read64(p)^secret[0],rapid_read64(p+8)^seed);
+    see1=rapid_mix(rapid_read64(p+16)^secret[1],rapid_read64(p+24)^see1);
+    see2=rapid_mix(rapid_read64(p+32)^secret[2],rapid_read64(p+40)^see2);
+    p+=48; i-=48;
+  } while (_likely_(i>=48));
+  rapidhash_internal_epilogue
+}
+
+
+static inline uint64_t rapidhash_internal_unrolled(const void *key, size_t len, uint64_t seed, const uint64_t* secret){
+  rapidhash_internal_prologue
+  while(_likely_(i>=96)){
+    seed=rapid_mix(rapid_read64(p)^secret[0],rapid_read64(p+8)^seed);
+    see1=rapid_mix(rapid_read64(p+16)^secret[1],rapid_read64(p+24)^see1);
+    see2=rapid_mix(rapid_read64(p+32)^secret[2],rapid_read64(p+40)^see2);
+    seed=rapid_mix(rapid_read64(p+48)^secret[0],rapid_read64(p+56)^seed);
+    see1=rapid_mix(rapid_read64(p+64)^secret[1],rapid_read64(p+72)^see1);
+    see2=rapid_mix(rapid_read64(p+80)^secret[2],rapid_read64(p+88)^see2);
+    p+=96; i-=96;
+  }
+  if(_unlikely_(i>=48)){
+    seed=rapid_mix(rapid_read64(p)^secret[0],rapid_read64(p+8)^seed);
+    see1=rapid_mix(rapid_read64(p+16)^secret[1],rapid_read64(p+24)^see1);
+    see2=rapid_mix(rapid_read64(p+32)^secret[2],rapid_read64(p+40)^see2);
+    p+=48; i-=48;
+  }
+  rapidhash_internal_epilogue
+}
+/*
+ *  rapidhash default seeded hash function.
+ *
+ *  @param key     Buffer to be hashed.
+ *  @param len     @key length, in bytes.
+ *  @param seed    64-bit seed used to alter the hash result predictably.
+ *
+ *  Calls rapidhash_internal using provided parameters and default secrets.
+ *
+ *  Returns a 64-bit hash.
+ */
+static inline uint64_t rapidhash_withSeed_compact(const void *key, size_t len, uint64_t seed) {
+  return rapidhash_internal_compact(key, len, seed, rapid_secret);
+}
+
+static inline uint64_t rapidhash_withSeed_unrolled(const void *key, size_t len, uint64_t seed) {
+  return rapidhash_internal_unrolled(key, len, seed, rapid_secret);
+}
+
+/*
+ *  rapidhash default hash function.
+ *
+ *  @param key     Buffer to be hashed.
+ *  @param len     @key length, in bytes.
+ *
+ *  Calls rapidhash_withSeed using provided parameters and the default seed.
+ *
+ *  Returns a 64-bit hash.
+ */
+static inline uint64_t rapidhash(const void *key, size_t len) {
+  return rapidhash_withSeed_unrolled(key, len, RAPID_SEED);
+}