diff --git a/CHANGELOG.md b/CHANGELOG.md
index c9facbc69e..fc81c393fe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -41,6 +41,7 @@
 - Deprecate unsafe host-specific bindings from stdlib. https://github.com/rescript-lang/rescript/pull/7334
 - Make unsafe function names consistent in Stdlib.String. https://github.com/rescript-lang/rescript/pull/7337
 - `rescript` package does not trigger `postinstall` script anymore. https://github.com/rescript-lang/rescript/pull/7350
+- Add Stdlib Bool and Char modules and improve Pervasives deprecation messages. https://github.com/rescript-lang/rescript/pull/7361
 
 #### :bug: Bug fix
 
diff --git a/analysis/reanalyze/src/ExnLib.ml b/analysis/reanalyze/src/ExnLib.ml
index 32463bbcde..255b483942 100644
--- a/analysis/reanalyze/src/ExnLib.ml
+++ b/analysis/reanalyze/src/ExnLib.ml
@@ -51,6 +51,8 @@ let raisesLibTable : (Name.t, Exceptions.t) Hashtbl.t =
     ]
   in
   let stdlibBigInt = [("fromStringExn", [jsExnError])] in
+  let stdlibBool = [("fromStringExn", [invalidArgument])] in
+  let stdlibChar = [("fromIntExn", [invalidArgument])] in
   let stdlibError = [("raise", [jsExnError])] in
   let stdlibExn =
     [
@@ -140,7 +142,8 @@ let raisesLibTable : (Name.t, Exceptions.t) Hashtbl.t =
     ("Belt_SetInt", beltSet);
     ("Belt_SetString", beltSet);
     ("BigInt", stdlibBigInt);
-    ("Char", [("chr", [invalidArgument])]);
+    ("Bool", stdlibBool);
+    ("Char", stdlibChar);
     ("Error", stdlibError);
     ("Exn", stdlibExn);
     ("Js.Json", [("parseExn", [jsExnError])]);
@@ -159,6 +162,10 @@ let raisesLibTable : (Name.t, Exceptions.t) Hashtbl.t =
     ("Stdlib", stdlib);
     ("Stdlib_BigInt", stdlibBigInt);
     ("Stdlib.BigInt", stdlibBigInt);
+    ("Stdlib_Bool", stdlibBool);
+    ("Stdlib.Bool", stdlibBool);
+    ("Stdlib_Char", stdlibChar);
+    ("Stdlib.Char", stdlibChar);
     ("Stdlib_Error", stdlibError);
     ("Stdlib.Error", stdlibError);
     ("Stdlib_Exn", stdlibExn);
diff --git a/lib/es6/Stdlib.js b/lib/es6/Stdlib.js
index 3d8f644de2..b92fc0a385 100644
--- a/lib/es6/Stdlib.js
+++ b/lib/es6/Stdlib.js
@@ -12,7 +12,7 @@ function assertEqual(a, b) {
     RE_EXN_ID: "Assert_failure",
     _1: [
       "Stdlib.res",
-      117,
+      119,
       4
     ],
     Error: new Error()
@@ -27,6 +27,10 @@ let $$Array;
 
 let $$BigInt;
 
+let Bool;
+
+let Char;
+
 let Console;
 
 let $$DataView;
@@ -118,6 +122,8 @@ export {
   IntervalId,
   $$Array,
   $$BigInt,
+  Bool,
+  Char,
   Console,
   $$DataView,
   $$Date,
diff --git a/lib/es6/Stdlib_Bool.js b/lib/es6/Stdlib_Bool.js
new file mode 100644
index 0000000000..9d19ce0902
--- /dev/null
+++ b/lib/es6/Stdlib_Bool.js
@@ -0,0 +1,43 @@
+
+
+
+function toString(b) {
+  if (b) {
+    return "true";
+  } else {
+    return "false";
+  }
+}
+
+function fromString(s) {
+  switch (s) {
+    case "false" :
+      return false;
+    case "true" :
+      return true;
+    default:
+      return;
+  }
+}
+
+function fromStringExn(param) {
+  switch (param) {
+    case "false" :
+      return false;
+    case "true" :
+      return true;
+    default:
+      throw {
+        RE_EXN_ID: "Invalid_argument",
+        _1: "Bool.fromStringExn: value is neither \"true\" nor \"false\"",
+        Error: new Error()
+      };
+  }
+}
+
+export {
+  toString,
+  fromString,
+  fromStringExn,
+}
+/* No side effect */
diff --git a/lib/es6/Char.js b/lib/es6/Stdlib_Char.js
similarity index 71%
rename from lib/es6/Char.js
rename to lib/es6/Stdlib_Char.js
index b2a6536046..b721476036 100644
--- a/lib/es6/Char.js
+++ b/lib/es6/Stdlib_Char.js
@@ -1,6 +1,25 @@
 
 
 
+function fromIntExn(n) {
+  if (n < 0 || n > 255) {
+    throw {
+      RE_EXN_ID: "Invalid_argument",
+      _1: "`Char.fromIntExn` expects an integer between 0 and 255",
+      Error: new Error()
+    };
+  }
+  return n;
+}
+
+function fromInt(n) {
+  if (n < 0 || n > 255) {
+    return;
+  } else {
+    return n;
+  }
+}
+
 function escaped(param) {
   let exit = 0;
   if (param >= 40) {
@@ -54,7 +73,7 @@ function escaped(param) {
   }
 }
 
-function lowercase_ascii(c) {
+function toLowerCaseAscii(c) {
   if (c >= /* 'A' */65 && c <= /* 'Z' */90) {
     return c + 32 | 0;
   } else {
@@ -62,7 +81,7 @@ function lowercase_ascii(c) {
   }
 }
 
-function uppercase_ascii(c) {
+function toUpperCaseAscii(c) {
   if (c >= /* 'a' */97 && c <= /* 'z' */122) {
     return c - 32 | 0;
   } else {
@@ -70,19 +89,17 @@ function uppercase_ascii(c) {
   }
 }
 
-function compare(c1, c2) {
-  return c1 - c2 | 0;
-}
+let lowercase_ascii = toLowerCaseAscii;
 
-function equal(c1, c2) {
-  return (c1 - c2 | 0) === 0;
-}
+let uppercase_ascii = toUpperCaseAscii;
 
 export {
   escaped,
   lowercase_ascii,
   uppercase_ascii,
-  compare,
-  equal,
+  toLowerCaseAscii,
+  toUpperCaseAscii,
+  fromIntExn,
+  fromInt,
 }
 /* No side effect */
diff --git a/lib/js/Stdlib.js b/lib/js/Stdlib.js
index faf8270b03..42b72d9938 100644
--- a/lib/js/Stdlib.js
+++ b/lib/js/Stdlib.js
@@ -12,7 +12,7 @@ function assertEqual(a, b) {
     RE_EXN_ID: "Assert_failure",
     _1: [
       "Stdlib.res",
-      117,
+      119,
       4
     ],
     Error: new Error()
@@ -27,6 +27,10 @@ let $$Array;
 
 let $$BigInt;
 
+let Bool;
+
+let Char;
+
 let Console;
 
 let $$DataView;
@@ -117,6 +121,8 @@ exports.TimeoutId = TimeoutId;
 exports.IntervalId = IntervalId;
 exports.$$Array = $$Array;
 exports.$$BigInt = $$BigInt;
+exports.Bool = Bool;
+exports.Char = Char;
 exports.Console = Console;
 exports.$$DataView = $$DataView;
 exports.$$Date = $$Date;
diff --git a/lib/js/Stdlib_Bool.js b/lib/js/Stdlib_Bool.js
new file mode 100644
index 0000000000..1cbc4d4216
--- /dev/null
+++ b/lib/js/Stdlib_Bool.js
@@ -0,0 +1,41 @@
+'use strict';
+
+
+function toString(b) {
+  if (b) {
+    return "true";
+  } else {
+    return "false";
+  }
+}
+
+function fromString(s) {
+  switch (s) {
+    case "false" :
+      return false;
+    case "true" :
+      return true;
+    default:
+      return;
+  }
+}
+
+function fromStringExn(param) {
+  switch (param) {
+    case "false" :
+      return false;
+    case "true" :
+      return true;
+    default:
+      throw {
+        RE_EXN_ID: "Invalid_argument",
+        _1: "Bool.fromStringExn: value is neither \"true\" nor \"false\"",
+        Error: new Error()
+      };
+  }
+}
+
+exports.toString = toString;
+exports.fromString = fromString;
+exports.fromStringExn = fromStringExn;
+/* No side effect */
diff --git a/lib/js/Char.js b/lib/js/Stdlib_Char.js
similarity index 69%
rename from lib/js/Char.js
rename to lib/js/Stdlib_Char.js
index e854a99cd0..1babbdfe04 100644
--- a/lib/js/Char.js
+++ b/lib/js/Stdlib_Char.js
@@ -1,6 +1,25 @@
 'use strict';
 
 
+function fromIntExn(n) {
+  if (n < 0 || n > 255) {
+    throw {
+      RE_EXN_ID: "Invalid_argument",
+      _1: "`Char.fromIntExn` expects an integer between 0 and 255",
+      Error: new Error()
+    };
+  }
+  return n;
+}
+
+function fromInt(n) {
+  if (n < 0 || n > 255) {
+    return;
+  } else {
+    return n;
+  }
+}
+
 function escaped(param) {
   let exit = 0;
   if (param >= 40) {
@@ -54,7 +73,7 @@ function escaped(param) {
   }
 }
 
-function lowercase_ascii(c) {
+function toLowerCaseAscii(c) {
   if (c >= /* 'A' */65 && c <= /* 'Z' */90) {
     return c + 32 | 0;
   } else {
@@ -62,7 +81,7 @@ function lowercase_ascii(c) {
   }
 }
 
-function uppercase_ascii(c) {
+function toUpperCaseAscii(c) {
   if (c >= /* 'a' */97 && c <= /* 'z' */122) {
     return c - 32 | 0;
   } else {
@@ -70,17 +89,15 @@ function uppercase_ascii(c) {
   }
 }
 
-function compare(c1, c2) {
-  return c1 - c2 | 0;
-}
+let lowercase_ascii = toLowerCaseAscii;
 
-function equal(c1, c2) {
-  return (c1 - c2 | 0) === 0;
-}
+let uppercase_ascii = toUpperCaseAscii;
 
 exports.escaped = escaped;
 exports.lowercase_ascii = lowercase_ascii;
 exports.uppercase_ascii = uppercase_ascii;
-exports.compare = compare;
-exports.equal = equal;
+exports.toLowerCaseAscii = toLowerCaseAscii;
+exports.toUpperCaseAscii = toUpperCaseAscii;
+exports.fromIntExn = fromIntExn;
+exports.fromInt = fromInt;
 /* No side effect */
diff --git a/packages/artifacts.txt b/packages/artifacts.txt
index 0b9c84e111..c63f048884 100644
--- a/packages/artifacts.txt
+++ b/packages/artifacts.txt
@@ -72,7 +72,6 @@ lib/es6/Belt_internalMapString.js
 lib/es6/Belt_internalSetBuckets.js
 lib/es6/Belt_internalSetInt.js
 lib/es6/Belt_internalSetString.js
-lib/es6/Char.js
 lib/es6/Dom.js
 lib/es6/Dom_storage.js
 lib/es6/Dom_storage2.js
@@ -149,6 +148,8 @@ lib/es6/Stdlib_AsyncIterator.js
 lib/es6/Stdlib_BigInt.js
 lib/es6/Stdlib_BigInt64Array.js
 lib/es6/Stdlib_BigUint64Array.js
+lib/es6/Stdlib_Bool.js
+lib/es6/Stdlib_Char.js
 lib/es6/Stdlib_Console.js
 lib/es6/Stdlib_DataView.js
 lib/es6/Stdlib_Date.js
@@ -243,7 +244,6 @@ lib/js/Belt_internalMapString.js
 lib/js/Belt_internalSetBuckets.js
 lib/js/Belt_internalSetInt.js
 lib/js/Belt_internalSetString.js
-lib/js/Char.js
 lib/js/Dom.js
 lib/js/Dom_storage.js
 lib/js/Dom_storage2.js
@@ -320,6 +320,8 @@ lib/js/Stdlib_AsyncIterator.js
 lib/js/Stdlib_BigInt.js
 lib/js/Stdlib_BigInt64Array.js
 lib/js/Stdlib_BigUint64Array.js
+lib/js/Stdlib_Bool.js
+lib/js/Stdlib_Char.js
 lib/js/Stdlib_Console.js
 lib/js/Stdlib_DataView.js
 lib/js/Stdlib_Date.js
@@ -619,12 +621,6 @@ lib/ocaml/Belt_internalSetString.cmi
 lib/ocaml/Belt_internalSetString.cmj
 lib/ocaml/Belt_internalSetString.cmt
 lib/ocaml/Belt_internalSetString.res
-lib/ocaml/Char.cmi
-lib/ocaml/Char.cmj
-lib/ocaml/Char.cmt
-lib/ocaml/Char.cmti
-lib/ocaml/Char.res
-lib/ocaml/Char.resi
 lib/ocaml/Dom.cmi
 lib/ocaml/Dom.cmj
 lib/ocaml/Dom.cmt
@@ -967,6 +963,18 @@ lib/ocaml/Stdlib_BigUint64Array.cmi
 lib/ocaml/Stdlib_BigUint64Array.cmj
 lib/ocaml/Stdlib_BigUint64Array.cmt
 lib/ocaml/Stdlib_BigUint64Array.res
+lib/ocaml/Stdlib_Bool.cmi
+lib/ocaml/Stdlib_Bool.cmj
+lib/ocaml/Stdlib_Bool.cmt
+lib/ocaml/Stdlib_Bool.cmti
+lib/ocaml/Stdlib_Bool.res
+lib/ocaml/Stdlib_Bool.resi
+lib/ocaml/Stdlib_Char.cmi
+lib/ocaml/Stdlib_Char.cmj
+lib/ocaml/Stdlib_Char.cmt
+lib/ocaml/Stdlib_Char.cmti
+lib/ocaml/Stdlib_Char.res
+lib/ocaml/Stdlib_Char.resi
 lib/ocaml/Stdlib_Console.cmi
 lib/ocaml/Stdlib_Console.cmj
 lib/ocaml/Stdlib_Console.cmt
diff --git a/runtime/Char.resi b/runtime/Char.resi
deleted file mode 100644
index 3ee638c888..0000000000
--- a/runtime/Char.resi
+++ /dev/null
@@ -1,54 +0,0 @@
-// FIXME:
-//   This exists for compatibility reason.
-//   Move this into Pervasives or Core
-
-/** Return the ASCII code of the argument. */
-@deprecated("Use Core instead. This will be removed in v13")
-external code: char => int = "%identity"
-
-/** Return the character with the given ASCII code.
-   Raise [Invalid_argument "Char.chr"] if the argument is
-   outside the range 0--255. */
-@deprecated("Use Core instead. This will be removed in v13")
-external chr: int => char = "%identity"
-
-/** Return a string representing the given character,
-    with special characters escaped following the lexical conventions
-    of OCaml.
-    All characters outside the ASCII printable range (32..126) are
-    escaped, as well as backslash, double-quote, and single-quote. */
-@deprecated("Use Core instead. This will be removed in v13")
-let escaped: char => string
-
-/** Convert the given character to its equivalent lowercase character,
-   using the US-ASCII character set.
-   @since 4.03.0 */
-@deprecated("Use Core instead. This will be removed in v13")
-let lowercase_ascii: char => char
-
-/** Convert the given character to its equivalent uppercase character,
-   using the US-ASCII character set.
-   @since 4.03.0 */
-@deprecated("Use Core instead. This will be removed in v13")
-let uppercase_ascii: char => char
-
-/** An alias for the type of characters. */
-@deprecated("Use `char` instead. This will be removed in v13")
-type t = char
-
-/** The comparison function for characters, with the same specification as
-    {!Pervasives.compare}.  Along with the type [t], this function [compare]
-    allows the module [Char] to be passed as argument to the functors
-    {!Set.Make} and {!Map.Make}. */
-@deprecated("Use Core instead. This will be removed in v13")
-let compare: (t, t) => int
-
-/** The equal function for chars.
-    @since 4.03.0 */
-@deprecated("Use Core instead. This will be removed in v13")
-let equal: (t, t) => bool
-
-/* The following is for system use only. Do not call directly. */
-
-@deprecated("Use Core instead. This will be removed in v13")
-external unsafe_chr: int => char = "%identity"
diff --git a/runtime/Pervasives.res b/runtime/Pervasives.res
index 12c46bab4a..555a503808 100644
--- a/runtime/Pervasives.res
+++ b/runtime/Pervasives.res
@@ -81,7 +81,7 @@ external \"||": (bool, bool) => bool = "%sequor"
 external succ: int => int = "%succint"
 external pred: int => int = "%predint"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Math.abs` instead. This will be removed in v13")
 let abs = x =>
   if x >= 0 {
     x
@@ -99,10 +99,10 @@ external lsl: (int, int) => int = "%lslint"
 external lsr: (int, int) => int = "%lsrint"
 external asr: (int, int) => int = "%asrint"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Int.Constants.maxValue` instead. This will be removed in v13")
 let max_int = lsr(-1, 1)
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Int.Constants.minValue` instead. This will be removed in v13")
 let min_int =
   max_int + 1
 
@@ -115,91 +115,91 @@ external \"-.": (float, float) => float = "%subfloat"
 external \"*.": (float, float) => float = "%mulfloat"
 external \"/.": (float, float) => float = "%divfloat"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.exp` instead. This will be removed in v13") @val @scope("Math")
 external exp: float => float = "exp"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.acos` instead. This will be removed in v13") @val @scope("Math")
 external acos: float => float = "acos"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.asin` instead. This will be removed in v13") @val @scope("Math")
 external asin: float => float = "asin"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.atan` instead. This will be removed in v13") @val @scope("Math")
 external atan: float => float = "atan"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.atan2` instead. This will be removed in v13") @val @scope("Math")
 external atan2: (float, float) => float = "atan2"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.cos` instead. This will be removed in v13") @val @scope("Math")
 external cos: float => float = "cos"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.cosh` instead. This will be removed in v13") @val @scope("Math")
 external cosh: float => float = "cosh"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.log` instead. This will be removed in v13") @val @scope("Math")
 external log: float => float = "log"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.log10` instead. This will be removed in v13") @val @scope("Math")
 external log10: float => float = "log10"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.log1p` instead. This will be removed in v13") @val @scope("Math")
 external log1p: float => float = "log1p"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use  `Math.sin` instead. This will be removed in v13") @val @scope("Math")
 external sin: float => float = "sin"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.sinh` instead. This will be removed in v13") @val @scope("Math")
 external sinh: float => float = "sinh"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.sqrt` instead. This will be removed in v13") @val @scope("Math")
 external sqrt: float => float = "sqrt"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.tan` instead. This will be removed in v13") @val @scope("Math")
 external tan: float => float = "tan"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.tanh` instead. This will be removed in v13") @val @scope("Math")
 external tanh: float => float = "tanh"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.ceil` instead. This will be removed in v13") @val @scope("Math")
 external ceil: float => float = "ceil"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.floor` instead. This will be removed in v13") @val @scope("Math")
 external floor: float => float = "floor"
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Math")
+@deprecated("Use `Math.abs` instead. This will be removed in v13") @val @scope("Math")
 external abs_float: float => float = "abs"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `%` instead. This will be removed in v13")
 external mod_float: (float, float) => float = "%modfloat"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Int.toFloat` instead. This will be removed in v13")
 external float: int => float = "%floatofint"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Int.toFloat` instead. This will be removed in v13")
 external float_of_int: int => float = "%floatofint"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Float.toInt` instead. This will be removed in v13")
 external truncate: float => int = "%intoffloat"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Float.toInt` instead. This will be removed in v13")
 external int_of_float: float => int = "%intoffloat"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Float.positiveInfinity` instead. This will be removed in v13")
 let infinity = 0x1p2047
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Float.negativeInfinity` instead. This will be removed in v13")
 let neg_infinity = -0x1p2047
 
-@deprecated("Use Core instead. This will be removed in v13") @val @scope("Number")
+@deprecated("Use `Float.nan` instead. This will be removed in v13") @val @scope("Number")
 external nan: float = "NaN"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Float.Constants.maxValue` instead. This will be removed in v13")
 let max_float = 1.79769313486231571e+308 /* 0x1.ffff_ffff_ffff_fp+1023 */
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Float.Constants.minValue` instead. This will be removed in v13")
 let min_float = 2.22507385850720138e-308 /* 0x1p-1022 */
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Float.Constants.epsilon` instead. This will be removed in v13")
 let epsilon_float = 2.22044604925031308e-16 /* 0x1p-52 */
 
 @deprecated("Do not use. This will be removed in v13")
@@ -232,13 +232,13 @@ external \"++": (string, string) => string = "%string_concat"
 
 /* Character operations -- more in module Char */
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Char.code` instead. This will be removed in v13")
 external int_of_char: char => int = "%identity"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Char.fromIntUnsafe` instead. This will be removed in v13")
 external unsafe_char_of_int: int => char = "%identity"
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Char.fromIntExn` instead. This will be removed in v13")
 let char_of_int = n =>
   if n < 0 || n > 255 {
     invalid_arg("char_of_int")
@@ -266,7 +266,7 @@ external decr: ref<int> => unit = "%decr"
 
 /* String conversion functions */
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Bool.toString` instead. This will be removed in v13")
 let string_of_bool = b =>
   if b {
     "true"
@@ -274,7 +274,7 @@ let string_of_bool = b =>
     "false"
   }
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Bool.fromString` instead. This will be removed in v13")
 let bool_of_string = param =>
   switch param {
   | "true" => true
@@ -282,7 +282,7 @@ let bool_of_string = param =>
   | _ => invalid_arg("bool_of_string")
   }
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Bool.fromString` instead. This will be removed in v13")
 let bool_of_string_opt = param =>
   switch param {
   | "true" => Some(true)
@@ -290,10 +290,10 @@ let bool_of_string_opt = param =>
   | _ => None
   }
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `Int.toString` instead. This will be removed in v13")
 external string_of_int: int => string = "String"
 
-@deprecated("Use Core instead. This will be removed in v13") @scope("Number")
+@deprecated("Use `Int.fromString` instead. This will be removed in v13") @scope("Number")
 external int_of_string: string => int = "parseInt"
 
 let int_of_string_opt = s =>
@@ -302,12 +302,12 @@ let int_of_string_opt = s =>
   | n => Some(n)
   }
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `String.get` instead. This will be removed in v13")
 external string_get: (string, int) => char = "%string_safe_get"
 
 /* List operations -- more in module List */
 
-@deprecated("Use Core instead. This will be removed in v13")
+@deprecated("Use `List.concat` instead. This will be removed in v13")
 let rec \"@" = (l1, l2) =>
   switch l1 {
   | list{} => l2
diff --git a/runtime/Stdlib.res b/runtime/Stdlib.res
index 743a4a651c..3a66acbaa1 100644
--- a/runtime/Stdlib.res
+++ b/runtime/Stdlib.res
@@ -2,6 +2,8 @@ include Stdlib_Global
 
 module Array = Stdlib_Array
 module BigInt = Stdlib_BigInt
+module Bool = Stdlib_Bool
+module Char = Stdlib_Char
 module Console = Stdlib_Console
 module DataView = Stdlib_DataView
 module Date = Stdlib_Date
diff --git a/runtime/Stdlib_Bool.res b/runtime/Stdlib_Bool.res
new file mode 100644
index 0000000000..0d4371ddfc
--- /dev/null
+++ b/runtime/Stdlib_Bool.res
@@ -0,0 +1,27 @@
+type t = bool
+
+let toString = b =>
+  if b {
+    "true"
+  } else {
+    "false"
+  }
+
+let fromString = s => {
+  switch s {
+  | "true" => Some(true)
+  | "false" => Some(false)
+  | _ => None
+  }
+}
+
+let fromStringExn = param =>
+  switch param {
+  | "true" => true
+  | "false" => false
+  | _ => raise(Invalid_argument(`Bool.fromStringExn: value is neither "true" nor "false"`))
+  }
+
+external compare: (bool, bool) => Stdlib_Ordering.t = "%compare"
+
+external equal: (bool, bool) => bool = "%equal"
diff --git a/runtime/Stdlib_Bool.resi b/runtime/Stdlib_Bool.resi
new file mode 100644
index 0000000000..8f69613134
--- /dev/null
+++ b/runtime/Stdlib_Bool.resi
@@ -0,0 +1,53 @@
+/***
+Functions for interacting with JavaScript booleans.
+See: [`Boolean`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)
+*/
+
+/**
+Type representing a boolean.
+*/
+type t = bool
+
+/**
+Converts a boolean to a string.
+
+## Examples
+```rescript
+Bool.toString(true)->assertEqual("true")
+Bool.toString(false)->assertEqual("false")
+```
+*/
+let toString: bool => string
+
+/**
+Converts a string to a boolean.
+
+## Examples
+```rescript
+Bool.fromString("true")->assertEqual(Some(true))
+Bool.fromString("false")->assertEqual(Some(false))
+Bool.fromString("notAValidBoolean")->assertEqual(None)
+```
+*/
+let fromString: string => option<bool>
+
+/**
+Converts a string to a boolean.
+Beware, this function will throw an `Invalid_argument` exception 
+if the string is not a valid boolean.
+
+## Examples
+```rescript
+Bool.fromStringExn("true")->assertEqual(true)
+Bool.fromStringExn("false")->assertEqual(false)
+switch Bool.fromStringExn("notAValidBoolean") {
+| exception Invalid_argument(_) => assert(true)
+| _ => assert(false)
+}
+```
+*/
+let fromStringExn: string => bool
+
+external compare: (bool, bool) => Stdlib_Ordering.t = "%compare"
+
+external equal: (bool, bool) => bool = "%equal"
diff --git a/runtime/Char.res b/runtime/Stdlib_Char.res
similarity index 65%
rename from runtime/Char.res
rename to runtime/Stdlib_Char.res
index 133e63b873..7e28ed66ae 100644
--- a/runtime/Char.res
+++ b/runtime/Stdlib_Char.res
@@ -1,9 +1,3 @@
-// FIXME:
-//   This exists for compatibility reason.
-//   Move this into Pervasives or Core
-
-// Below is all deprecated and should be removed in v13
-
 type t = char
 
 external code: t => int = "%identity"
@@ -12,6 +6,22 @@ external unsafe_chr: int => t = "%identity"
 
 external chr: int => t = "%identity"
 
+external fromIntUnsafe: int => t = "%identity"
+
+let fromIntExn = n =>
+  if n < 0 || n > 255 {
+    raise(Invalid_argument("`Char.fromIntExn` expects an integer between 0 and 255"))
+  } else {
+    fromIntUnsafe(n)
+  }
+
+let fromInt = n =>
+  if n < 0 || n > 255 {
+    None
+  } else {
+    Some(fromIntUnsafe(n))
+  }
+
 external bytes_create: int => array<char> = "Array"
 
 external bytes_unsafe_set: (array<'a>, int, 'a) => unit = "%array_unsafe_set"
@@ -41,19 +51,23 @@ let escaped = param =>
     unsafe_to_string(s)
   }
 
-let lowercase_ascii = c =>
+let toLowerCaseAscii = c =>
   if c >= 'A' && c <= 'Z' {
     unsafe_chr(code(c) + 32)
   } else {
     c
   }
 
-let uppercase_ascii = c =>
+let lowercase_ascii = toLowerCaseAscii
+
+let toUpperCaseAscii = c =>
   if c >= 'a' && c <= 'z' {
     unsafe_chr(code(c) - 32)
   } else {
     c
   }
 
-let compare = (c1, c2) => code(c1) - code(c2)
-let equal = (c1: t, c2: t) => compare(c1, c2) == 0
+let uppercase_ascii = toUpperCaseAscii
+
+external equal: (char, char) => bool = "%equal"
+external compare: (char, char) => Stdlib_Ordering.t = "%compare"
diff --git a/runtime/Stdlib_Char.resi b/runtime/Stdlib_Char.resi
new file mode 100644
index 0000000000..3943f1d73b
--- /dev/null
+++ b/runtime/Stdlib_Char.resi
@@ -0,0 +1,92 @@
+/***
+ Functions for interacting with ASCII char type.
+ */
+
+/** 
+Type representing an ASCII char.
+*/
+type t = char
+
+/** Return the ASCII code of the argument. */
+external code: char => int = "%identity"
+
+/** Return the character with the given ASCII code.
+   Beware this function is unsafe. */
+@deprecated("Use `Char.fromIntExn` instead. This will be removed in v13")
+external chr: int => char = "%identity"
+
+/** Return a string representing the given character,
+    with special characters escaped following the lexical conventions
+    of OCaml.
+    All characters outside the ASCII printable range (32..126) are
+    escaped, as well as backslash, double-quote, and single-quote. */
+let escaped: char => string
+
+/** Convert the given character to its equivalent lowercase character,
+   using the US-ASCII character set.
+   @since 4.03.0 */
+@deprecated("Use `Char.toLowerCaseAscii` instead. This will be removed in v13")
+let lowercase_ascii: char => char
+
+/** Convert the given character to its equivalent uppercase character,
+   using the US-ASCII character set.
+   @since 4.03.0 */
+@deprecated("Use `Char.toUpperCaseAscii` instead. This will be removed in v13")
+let uppercase_ascii: char => char
+
+/** 
+Convert the given character to its equivalent lowercase character,
+using the US-ASCII character set. 
+
+## Examples
+
+```rescript
+Char.toLowerCaseAscii('A')->assertEqual('a')
+Char.toLowerCaseAscii('Z')->assertEqual('z')
+Char.toLowerCaseAscii('a')->assertEqual('a')
+```
+*/
+let toLowerCaseAscii: char => char
+
+/** 
+Convert the given character to its equivalent uppercase character,
+using the US-ASCII character set. 
+
+## Examples
+
+```rescript
+Char.toUpperCaseAscii('a')->assertEqual('A')
+Char.toUpperCaseAscii('z')->assertEqual('Z')
+Char.toUpperCaseAscii('A')->assertEqual('A')
+```
+
+*/
+let toUpperCaseAscii: char => char
+
+/** The comparison function for characters. */
+external compare: (char, char) => Stdlib_Ordering.t = "%compare"
+
+/** The equal function for chars. */
+external equal: (char, char) => bool = "%equal"
+
+/* The following is for system use only. Do not call directly. */
+@deprecated("Use `Char.fromIntUnsafe` instead. This will be removed in v13")
+external unsafe_chr: int => char = "%identity"
+
+/** 
+Return the character with the given ASCII code.
+Beware this function is unsafe. 
+*/
+external fromIntUnsafe: int => t = "%identity"
+
+/**
+Return the character with the given ASCII code.
+Raise an `invalid_arg` exception if the argument is not a valid ASCII code.
+*/
+let fromIntExn: int => t
+
+/**
+Return the character with the given ASCII code.
+Return `None` if the argument is not a valid ASCII code.
+*/
+let fromInt: int => option<t>
diff --git a/runtime/Stdlib_List.resi b/runtime/Stdlib_List.resi
index 1b05db8d19..f0ffe2a3c0 100644
--- a/runtime/Stdlib_List.resi
+++ b/runtime/Stdlib_List.resi
@@ -275,12 +275,12 @@ list{0, 1, 2, 3, 4}->List.splitAt(2) // Some((list{0, 1}, list{2, 3, 4}))
 let splitAt: (list<'a>, int) => option<(list<'a>, list<'a>)>
 
 /**
-`concat(list1, list2)` returns the list obtained by adding `list1` after `list2`.
+`concat(list1, list2)` returns the list obtained by adding `list2` after `list1`.
 
 ## Examples
 
 ```rescript
-List.concat(list{1, 2, 3}, list{4, 5}) // list{1, 2, 3, 4, 5}
+List.concat(list{1, 2, 3}, list{4, 5})->assertEqual(list{1, 2, 3, 4, 5})
 ```
 */
 let concat: (list<'a>, list<'a>) => list<'a>
diff --git a/tests/tests/src/coercion_module_alias_test.mjs b/tests/tests/src/coercion_module_alias_test.mjs
index d8615b6cdd..aa79854769 100644
--- a/tests/tests/src/coercion_module_alias_test.mjs
+++ b/tests/tests/src/coercion_module_alias_test.mjs
@@ -1,19 +1,19 @@
 // Generated by ReScript, PLEASE EDIT WITH CARE
 
-import * as Char from "rescript/lib/es6/Char.js";
 import * as Belt_List from "rescript/lib/es6/Belt_List.js";
+import * as Stdlib_Char from "rescript/lib/es6/Stdlib_Char.js";
 
 function l(prim) {
   console.log(prim);
 }
 
-let C$p = Char;
+let C$p = Stdlib_Char;
 
 console.log(66);
 
 console.log(66);
 
-let C3 = Char;
+let C3 = Stdlib_Char;
 
 console.log(66);
 
@@ -24,10 +24,10 @@ function g(x) {
 }
 
 function F(X) {
-  return Char;
+  return Stdlib_Char;
 }
 
-let C4 = Char;
+let C4 = Stdlib_Char;
 
 console.log(66);
 
@@ -163,7 +163,7 @@ let C;
 
 let C$p$p$p = C$p;
 
-let C$p$p = Char;
+let C$p$p = Stdlib_Char;
 
 function G0(funarg) {
   let N = {
diff --git a/tests/tests/src/ocaml_compat/Ocaml_String.mjs b/tests/tests/src/ocaml_compat/Ocaml_String.mjs
index 42bc5b9d05..d15f3d601c 100644
--- a/tests/tests/src/ocaml_compat/Ocaml_String.mjs
+++ b/tests/tests/src/ocaml_compat/Ocaml_String.mjs
@@ -1,8 +1,8 @@
 // Generated by ReScript, PLEASE EDIT WITH CARE
 
-import * as Char from "rescript/lib/es6/Char.js";
 import * as Pervasives from "rescript/lib/es6/Pervasives.js";
 import * as Ocaml_Array from "./Ocaml_Array.mjs";
+import * as Stdlib_Char from "rescript/lib/es6/Stdlib_Char.js";
 import * as Primitive_exceptions from "rescript/lib/es6/Primitive_exceptions.js";
 
 function apply1(f, bytes) {
@@ -83,7 +83,7 @@ function escaped(s) {
     return s;
   }
   let bytes = bos(s);
-  return Ocaml_Array.map(Char.escaped, bytes).join("");
+  return Ocaml_Array.map(Stdlib_Char.escaped, bytes).join("");
 }
 
 function index_rec(s, lim, _i, c) {
@@ -237,22 +237,22 @@ function rcontains_from(s, i, c) {
 
 function uppercase_ascii(s) {
   let bytes = bos(s);
-  return String.fromCodePoint(...Ocaml_Array.map(Char.uppercase_ascii, bytes));
+  return String.fromCodePoint(...Ocaml_Array.map(Stdlib_Char.uppercase_ascii, bytes));
 }
 
 function lowercase_ascii(s) {
   let bytes = bos(s);
-  return String.fromCodePoint(...Ocaml_Array.map(Char.lowercase_ascii, bytes));
+  return String.fromCodePoint(...Ocaml_Array.map(Stdlib_Char.lowercase_ascii, bytes));
 }
 
 function capitalize_ascii(s) {
   let bytes = bos(s);
-  return String.fromCodePoint(...apply1(Char.uppercase_ascii, bytes));
+  return String.fromCodePoint(...apply1(Stdlib_Char.uppercase_ascii, bytes));
 }
 
 function uncapitalize_ascii(s) {
   let bytes = bos(s);
-  return String.fromCodePoint(...apply1(Char.lowercase_ascii, bytes));
+  return String.fromCodePoint(...apply1(Stdlib_Char.lowercase_ascii, bytes));
 }
 
 function split_on_char(sep, s) {
diff --git a/tests/tests/src/ocaml_compat/Ocaml_String.res b/tests/tests/src/ocaml_compat/Ocaml_String.res
index 2c0f049e68..dd54f93463 100644
--- a/tests/tests/src/ocaml_compat/Ocaml_String.res
+++ b/tests/tests/src/ocaml_compat/Ocaml_String.res
@@ -11,8 +11,8 @@ type t = string
 module B = {
   include Array
 
-  let uppercase_ascii = bytes => map(Char.uppercase_ascii, bytes)
-  let lowercase_ascii = bytes => map(Char.lowercase_ascii, bytes)
+  let uppercase_ascii = bytes => map(Stdlib.Char.uppercase_ascii, bytes)
+  let lowercase_ascii = bytes => map(Stdlib.Char.lowercase_ascii, bytes)
 
   let apply1 = (f, bytes) =>
     if length(bytes) == 0 {
@@ -22,10 +22,10 @@ module B = {
       unsafe_set(r, 0, f(unsafe_get(bytes, 0)))
       r
     }
-  let capitalize_ascii = bytes => apply1(Char.uppercase_ascii, bytes)
-  let uncapitalize_ascii = bytes => apply1(Char.lowercase_ascii, bytes)
+  let capitalize_ascii = bytes => apply1(Stdlib.Char.uppercase_ascii, bytes)
+  let uncapitalize_ascii = bytes => apply1(Stdlib.Char.lowercase_ascii, bytes)
 
-  let escaped = bytes => map(Char.escaped, bytes)
+  let escaped = bytes => map(Stdlib.Char.escaped, bytes)
 }
 
 @send external join: (array<string>, string) => string = "join"
diff --git a/tests/tests/src/test_char.res b/tests/tests/src/test_char.res
index 22d0122223..3dc84c52fa 100644
--- a/tests/tests/src/test_char.res
+++ b/tests/tests/src/test_char.res
@@ -1,4 +1,4 @@
 let caml_is_printable = c => {
-  let code = Char.code(c)
+  let code = Stdlib.Char.code(c)
   code > 31 && code < 127
 }