diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9b4deda7..222470b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Next version
 
+- Optimize compare and equal functions. https://github.com/rescript-association/rescript-core/pull/238
+
 ## 1.5.2
 
 - Remove aliases for runtime modules (`MapperRt`, `Internal`) and `Re`. https://github.com/rescript-association/rescript-core/pull/237
diff --git a/src/Core__Date.mjs b/src/Core__Date.mjs
index bb84ed38..38e6e98f 100644
--- a/src/Core__Date.mjs
+++ b/src/Core__Date.mjs
@@ -1,6 +1,6 @@
 // Generated by ReScript, PLEASE EDIT WITH CARE
 
-import * as Core__Float from "./Core__Float.mjs";
+import * as Caml from "rescript/lib/es6/caml.js";
 
 var UTC = {};
 
@@ -9,7 +9,7 @@ function equal(a, b) {
 }
 
 function compare(a, b) {
-  return Core__Float.compare(a.getTime(), b.getTime());
+  return Caml.float_compare(a.getTime(), b.getTime());
 }
 
 export {
diff --git a/src/Core__Float.mjs b/src/Core__Float.mjs
index 44a3d032..9fb41d4c 100644
--- a/src/Core__Float.mjs
+++ b/src/Core__Float.mjs
@@ -3,20 +3,6 @@
 
 var Constants = {};
 
-function equal(a, b) {
-  return a === b;
-}
-
-function compare(a, b) {
-  if (a < b) {
-    return -1;
-  } else if (a > b) {
-    return 1;
-  } else {
-    return 0;
-  }
-}
-
 function fromString(i) {
   var i$1 = parseFloat(i);
   if (isNaN(i$1)) {
@@ -37,8 +23,6 @@ function clamp(min, max, value) {
 
 export {
   Constants ,
-  equal ,
-  compare ,
   fromString ,
   clamp ,
 }
diff --git a/src/Core__Float.res b/src/Core__Float.res
index ada4de71..c701db92 100644
--- a/src/Core__Float.res
+++ b/src/Core__Float.res
@@ -7,10 +7,9 @@ module Constants = {
   @val external maxValue: float = "Number.MAX_VALUE"
 }
 
-let equal = (a: float, b: float) => a === b
+external equal: (float, float) => bool = "%equal"
 
-let compare = (a: float, b: float) =>
-  a < b ? Core__Ordering.less : a > b ? Core__Ordering.greater : Core__Ordering.equal
+external compare: (float, float) => Core__Ordering.t = "%compare"
 
 @val external isNaN: float => bool = "isNaN"
 @val external isFinite: float => bool = "isFinite"
diff --git a/src/Core__Float.resi b/src/Core__Float.resi
index 9609147e..806d8df9 100644
--- a/src/Core__Float.resi
+++ b/src/Core__Float.resi
@@ -109,9 +109,9 @@ module Constants: {
   external maxValue: float = "Number.MAX_VALUE"
 }
 
-let equal: (float, float) => bool
+external equal: (float, float) => bool = "%equal"
 
-let compare: (float, float) => Core__Ordering.t
+external compare: (float, float) => Core__Ordering.t = "%compare"
 
 /**
 `isNaN(v)` tests if the given `v` is `NaN`.
diff --git a/src/Core__Int.mjs b/src/Core__Int.mjs
index 96f246a0..7900b26f 100644
--- a/src/Core__Int.mjs
+++ b/src/Core__Int.mjs
@@ -2,20 +2,6 @@
 
 import * as Core__Array from "./Core__Array.mjs";
 
-function equal(a, b) {
-  return a === b;
-}
-
-function compare(a, b) {
-  if (a < b) {
-    return -1;
-  } else if (a > b) {
-    return 1;
-  } else {
-    return 0;
-  }
-}
-
 function fromString(x, radix) {
   var maybeInt = radix !== undefined ? parseInt(x, radix) : parseInt(x);
   if (isNaN(maybeInt) || maybeInt > 2147483647 || maybeInt < -2147483648) {
@@ -85,8 +71,6 @@ var Constants = {
 
 export {
   Constants ,
-  equal ,
-  compare ,
   fromString ,
   range ,
   rangeWithOptions ,
diff --git a/src/Core__Int.res b/src/Core__Int.res
index 94d57c62..b1a0f22e 100644
--- a/src/Core__Int.res
+++ b/src/Core__Int.res
@@ -3,10 +3,9 @@ module Constants = {
   @inline let maxValue = 2147483647
 }
 
-let equal = (a: int, b: int) => a === b
+external equal: (int, int) => bool = "%equal"
 
-let compare = (a: int, b: int) =>
-  a < b ? Core__Ordering.less : a > b ? Core__Ordering.greater : Core__Ordering.equal
+external compare: (int, int) => Core__Ordering.t = "%compare"
 
 @send external toExponential: (int, ~digits: int=?) => string = "toExponential"
 @deprecated("Use `toExponential` instead") @send
diff --git a/src/Core__Int.resi b/src/Core__Int.resi
index 37c44ac3..bb74f75a 100644
--- a/src/Core__Int.resi
+++ b/src/Core__Int.resi
@@ -56,9 +56,9 @@ module Constants: {
   let maxValue: int
 }
 
-let equal: (int, int) => bool
+external equal: (int, int) => bool = "%equal"
 
-let compare: (int, int) => Core__Ordering.t
+external compare: (int, int) => Core__Ordering.t = "%compare"
 
 /**
 `toExponential(n, ~digits=?)` return a `string` representing the given value in
diff --git a/src/Core__String.mjs b/src/Core__String.mjs
index c6f60393..1b8a0b9f 100644
--- a/src/Core__String.mjs
+++ b/src/Core__String.mjs
@@ -1,20 +1,6 @@
 // Generated by ReScript, PLEASE EDIT WITH CARE
 
 
-function equal(a, b) {
-  return a === b;
-}
-
-function compare(a, b) {
-  if (a < b) {
-    return -1;
-  } else if (a > b) {
-    return 1;
-  } else {
-    return 0;
-  }
-}
-
 function indexOfOpt(s, search) {
   var index = s.indexOf(search);
   if (index !== -1) {
@@ -40,8 +26,6 @@ function searchOpt(s, re) {
 }
 
 export {
-  equal ,
-  compare ,
   indexOfOpt ,
   lastIndexOfOpt ,
   searchOpt ,
diff --git a/src/Core__String.res b/src/Core__String.res
index 22db37b5..392c3165 100644
--- a/src/Core__String.res
+++ b/src/Core__String.res
@@ -6,10 +6,9 @@
 @val external fromCodePoint: int => string = "String.fromCodePoint"
 @variadic @val external fromCodePointMany: array<int> => string = "String.fromCodePoint"
 
-let equal = (a: string, b: string) => a === b
+external equal: (string, string) => bool = "%equal"
 
-let compare = (a: string, b: string) =>
-  a < b ? Core__Ordering.less : a > b ? Core__Ordering.greater : Core__Ordering.equal
+external compare: (string, string) => Core__Ordering.t = "%compare"
 
 @get external length: string => int = "length"
 @get_index external get: (string, int) => option<string> = ""
diff --git a/src/Core__String.resi b/src/Core__String.resi
index b3e429ba..99e5b6df 100644
--- a/src/Core__String.resi
+++ b/src/Core__String.resi
@@ -118,9 +118,9 @@ String.fromCodePointMany([0xd55c, 0xae00, 0x1f63a]) == `한글😺`
 @val
 external fromCodePointMany: array<int> => string = "String.fromCodePoint"
 
-let equal: (string, string) => bool
+external equal: (string, string) => bool = "%equal"
 
-let compare: (string, string) => Core__Ordering.t
+external compare: (string, string) => Core__Ordering.t = "%compare"
 
 /**
 `length(str)` returns the length of the given `string`.
diff --git a/test/FloatTests.mjs b/test/FloatTests.mjs
index 013aaabb..10d8de3a 100644
--- a/test/FloatTests.mjs
+++ b/test/FloatTests.mjs
@@ -237,6 +237,16 @@ Test.run([
       "clamp - min -infinity, max -infinity"
     ], Core__Float.clamp(PervasivesU.neg_infinity, PervasivesU.neg_infinity, 4.2), eq, PervasivesU.neg_infinity);
 
+Test.run([
+      [
+        "FloatTests.res",
+        49,
+        20,
+        46
+      ],
+      "Float.equal optimization"
+    ], false, eq, false);
+
 export {
   eq ,
 }
diff --git a/test/FloatTests.res b/test/FloatTests.res
index c9f933ca..8ca2d201 100644
--- a/test/FloatTests.res
+++ b/test/FloatTests.res
@@ -45,3 +45,5 @@ Test.run(
   eq,
   neg_infinity,
 )
+
+Test.run(__POS_OF__("Float.equal optimization"), Float.equal(1., 3.), eq, false)
diff --git a/test/IntTests.mjs b/test/IntTests.mjs
index 593fb9eb..2ab9a0ce 100644
--- a/test/IntTests.mjs
+++ b/test/IntTests.mjs
@@ -548,6 +548,16 @@ Test.run([
       "clamp - > min, > max"
     ], Core__Int.clamp(40, 40, 42), eq, 40);
 
+Test.run([
+      [
+        "IntTests.res",
+        170,
+        20,
+        44
+      ],
+      "Int.equal optimization"
+    ], false, eq, false);
+
 export {
   eq ,
   $$catch ,
diff --git a/test/IntTests.res b/test/IntTests.res
index 4535b18e..ebbb7e8c 100644
--- a/test/IntTests.res
+++ b/test/IntTests.res
@@ -166,3 +166,5 @@ Test.run(__POS_OF__("clamp - < min, < max"), Int.clamp(~min=50, ~max=60, 42), eq
 Test.run(__POS_OF__("clamp - < min, > max"), Int.clamp(~min=50, ~max=40, 42), eq, 50) // min wins
 Test.run(__POS_OF__("clamp - > min, < max"), Int.clamp(~min=40, ~max=60, 42), eq, 42)
 Test.run(__POS_OF__("clamp - > min, > max"), Int.clamp(~min=40, ~max=40, 42), eq, 40)
+
+Test.run(__POS_OF__("Int.equal optimization"), Int.equal(1, 3), eq, false)
diff --git a/test/StringTests.mjs b/test/StringTests.mjs
new file mode 100644
index 00000000..9bb62166
--- /dev/null
+++ b/test/StringTests.mjs
@@ -0,0 +1,21 @@
+// Generated by ReScript, PLEASE EDIT WITH CARE
+
+import * as Test from "./Test.mjs";
+import * as Caml_obj from "rescript/lib/es6/caml_obj.js";
+
+var eq = Caml_obj.equal;
+
+Test.run([
+      [
+        "StringTests.res",
+        5,
+        20,
+        47
+      ],
+      "String.equal optimization"
+    ], false, eq, false);
+
+export {
+  eq ,
+}
+/*  Not a pure module */
diff --git a/test/StringTests.res b/test/StringTests.res
new file mode 100644
index 00000000..a476d408
--- /dev/null
+++ b/test/StringTests.res
@@ -0,0 +1,5 @@
+open RescriptCore
+
+let eq = (a, b) => a == b
+
+Test.run(__POS_OF__("String.equal optimization"), String.equal("one", "three"), eq, false)