diff --git a/app/gui2/src/components/visualizations/JSONVisualization/JsonPrimitiveWidget.vue b/app/gui2/src/components/visualizations/JSONVisualization/JsonPrimitiveWidget.vue
index ef0608111736..25e962904b15 100644
--- a/app/gui2/src/components/visualizations/JSONVisualization/JsonPrimitiveWidget.vue
+++ b/app/gui2/src/components/visualizations/JSONVisualization/JsonPrimitiveWidget.vue
@@ -29,6 +29,7 @@ const primitive = computed(() => {
 <style scoped>
 .string {
   color: darkgreen;
+  white-space: pre-wrap;
 }
 .number {
   color: darkgreen;
diff --git a/app/gui2/src/components/visualizations/TableVisualization.vue b/app/gui2/src/components/visualizations/TableVisualization.vue
index b98f630cd8b8..2fec21f1dba3 100644
--- a/app/gui2/src/components/visualizations/TableVisualization.vue
+++ b/app/gui2/src/components/visualizations/TableVisualization.vue
@@ -229,7 +229,7 @@ const numberFormat = new Intl.NumberFormat(undefined, {
 function formatNumber(params: ICellRendererParams) {
   const valueType = params.value?.type
   let value
-  if (valueType === 'BigInt') {
+  if (valueType === 'Integer') {
     value = BigInt(params.value?.value)
   } else if (valueType === 'Decimal') {
     value = Number(params.value?.value)
diff --git a/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Decimal.enso b/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Decimal.enso
index 77fafbdd2e33..668679b9bffc 100644
--- a/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Decimal.enso
+++ b/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Decimal.enso
@@ -999,6 +999,12 @@ type Decimal
     scale : Integer
     scale self = self.big_decimal.scale
 
+    ## PRIVATE
+    with_scale : Integer -> Decimal
+    private with_scale self new_scale:Integer =
+        if self.scale == new_scale then self else
+            Decimal.Value (self.big_decimal.setScale new_scale)
+
     ## PRIVATE
     unscaled_value : Integer
     unscaled_value self = self.big_decimal.unscaledValue
diff --git a/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Json.enso b/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Json.enso
index a7020a0d67e9..c9c689ca2e70 100644
--- a/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Json.enso
+++ b/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Json.enso
@@ -1,6 +1,7 @@
 import project.Any.Any
 import project.Data.Array.Array
 import project.Data.Array_Proxy.Array_Proxy
+import project.Data.Decimal.Decimal
 import project.Data.Map.Map
 import project.Data.Numbers.Float
 import project.Data.Numbers.Integer
@@ -413,9 +414,12 @@ make_enso object =
         js_object : JS_Object ->
             ## Handle deserializing date and time types.
             type_name = js_object.get "type"
-            parsed = if type_name == "Date" then Date.from js_object else
-                if type_name == "Date_Time" then Date_Time.from js_object else
-                    if type_name == "Time_Of_Day" then Time_Of_Day.from js_object else
-                        js_object
+            parsed = case type_name of
+                "Date" -> Date.from js_object
+                "Date_Time" -> Date_Time.from js_object
+                "Time_Of_Day" -> Time_Of_Day.from js_object
+                "Decimal" -> Decimal.from js_object
+                "Integer" -> Integer.from js_object
+                _ -> js_object
 
             if parsed.is_error then js_object else parsed
diff --git a/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Json/Extensions.enso b/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Json/Extensions.enso
index c5ad239dc9d6..edb0d267fa21 100644
--- a/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Json/Extensions.enso
+++ b/distribution/lib/Standard/Base/0.0.0-dev/src/Data/Json/Extensions.enso
@@ -2,6 +2,7 @@ import project.Any.Any
 import project.Data.Array.Array
 import project.Data.Array_Proxy.Array_Proxy
 import project.Data.Decimal.Decimal
+import project.Data.Numeric.Math_Context.Math_Context
 import project.Data.Json.JS_Object
 import project.Data.Json.Json
 import project.Data.Locale.Locale
@@ -13,6 +14,7 @@ import project.Data.Text.Text
 import project.Data.Text.Text_Sub_Range.Text_Sub_Range
 import project.Data.Vector.Vector
 import project.Error.Error
+import project.Errors.Illegal_Argument.Illegal_Argument
 import project.Errors.Deprecated.Deprecated
 import project.Meta
 import project.Nothing.Nothing
@@ -57,15 +59,32 @@ Number.to_js_object self = case self of
         ## JS Safe Integer range -(2^53 - 1) to (2^53 - 1)
         js_max_integer = 9007199254740991
         if self >= -js_max_integer && self < js_max_integer then self else
-            JS_Object.from_pairs [["type", "BigInt"], ["value", self.to_text]]
+            JS_Object.from_pairs [["type", "Integer"], ["value", self.to_text]]
     _ -> self
 
+## PRIVATE
+   Converts a JS_Object to an Integer.
+Integer.from (that:JS_Object) =
+    case that.get "type" == "Integer" && ["value"].all that.contains_key of
+        True -> Integer.parse (that.at "value")
+        False -> Error.throw (Illegal_Argument.Error "Invalid JS_Object for Integer.")
+
 ## PRIVATE
    Converts the given value to a JSON serializable object.
 Decimal.to_js_object : JS_Object
 Decimal.to_js_object self =
     JS_Object.from_pairs [["type", "Decimal"], ["value", self.to_text], ["scale", self.scale], ["precision", self.precision]]
 
+## PRIVATE
+   Converts a JS_Object to a Decimal.
+Decimal.from (that:JS_Object) =
+    case that.get "type" == "Decimal" && ["value", "scale", "precision"].all that.contains_key of
+        True ->
+            math_context = Math_Context.new (that.at "precision")
+            raw_value = Decimal.from_string (that.at "value") math_context
+            raw_value.with_scale (that.at "scale")
+        False -> Error.throw (Illegal_Argument.Error "Invalid JS_Object for Decimal.")
+
 ## PRIVATE
    Converts the given value to a JSON serializable object.
    For Nothing, booleans, numbers and strings, this is the value itself.
diff --git a/test/Base_Tests/src/Data/Json_Spec.enso b/test/Base_Tests/src/Data/Json_Spec.enso
index 049e07e8ade5..799d50625a59 100644
--- a/test/Base_Tests/src/Data/Json_Spec.enso
+++ b/test/Base_Tests/src/Data/Json_Spec.enso
@@ -153,6 +153,18 @@ add_specs suite_builder =
             Number.positive_infinity.to_json . should_equal "null"
             Number.negative_infinity.to_json . should_equal "null"
 
+        group_builder.specify "should serialise large integers and parse back" <|
+            large_number = 1234567890123456789012345678901234567890
+            large_number.to_json . should_equal '{"type":"Integer","value":"1234567890123456789012345678901234567890"}'
+            large_number.to_json . parse_json . should_equal large_number
+
+        group_builder.specify "should serialise decimals and parse back" <|
+            decimal = Decimal.from_string "1234567890123456789012345678901234567890.1234567890123456789012345678901234567890"
+            decimal.to_json . should_equal '{"type":"Decimal","value":"1234567890123456789012345678901234567890.1234567890123456789012345678901234567890","scale":40,"precision":80}'
+            decimal.to_json . parse_json . should_equal decimal
+            decimal.to_json . parse_json . scale . should_equal 40
+            decimal.to_json . parse_json . precision . should_equal 80
+
     suite_builder.group "JS_Object" group_builder->
         group_builder.specify "should be buildable from pairs" <|
             JS_Object.from_pairs [["foo", "bar"]] . to_json . should_equal '{"foo":"bar"}'