diff --git a/priv/test_cases/noncharacter.json b/priv/test_cases/noncharacter.json
deleted file mode 100644
index 09db417..0000000
--- a/priv/test_cases/noncharacter.json
+++ /dev/null
@@ -1 +0,0 @@
-"﷐"
\ No newline at end of file
diff --git a/priv/test_cases/noncharacter.test b/priv/test_cases/noncharacter.test
deleted file mode 100644
index 6b3732c..0000000
--- a/priv/test_cases/noncharacter.test
+++ /dev/null
@@ -1,3 +0,0 @@
-{name, "noncharacter"}.
-{jsx, {error, badjson}}.
-{json, "noncharacter.json"}.
\ No newline at end of file
diff --git a/priv/test_cases/noncharacter_replaced.json b/priv/test_cases/noncharacter_replaced.json
deleted file mode 100644
index 09db417..0000000
--- a/priv/test_cases/noncharacter_replaced.json
+++ /dev/null
@@ -1 +0,0 @@
-"﷐"
\ No newline at end of file
diff --git a/priv/test_cases/noncharacter_replaced.test b/priv/test_cases/noncharacter_replaced.test
deleted file mode 100644
index 0944886..0000000
--- a/priv/test_cases/noncharacter_replaced.test
+++ /dev/null
@@ -1,4 +0,0 @@
-{name, "noncharacter replaced"}.
-{jsx, [{string,<<16#fffd/utf8>>},end_json]}.
-{json, "noncharacter_replaced.json"}.
-{jsx_flags, [loose_unicode]}.
\ No newline at end of file
diff --git a/src/jsx_decoder.erl b/src/jsx_decoder.erl
index f70e0f8..c198253 100644
--- a/src/jsx_decoder.erl
+++ b/src/jsx_decoder.erl
@@ -145,11 +145,11 @@ value(<<$f, Rest/binary>>, Handler, Stack, Opts) ->
 value(<<$n, Rest/binary>>, Handler, Stack, Opts) ->
     nu(Rest, Handler, Stack, Opts);
 value(<<?negative, Rest/binary>>, Handler, Stack, Opts) ->
-    negative(Rest, Handler, [?new_seq($-)|Stack], Opts);
+    negative(Rest, Handler, [[$-]|Stack], Opts);
 value(<<?zero, Rest/binary>>, Handler, Stack, Opts) ->
-    zero(Rest, Handler, [?new_seq($0)|Stack], Opts);
+    zero(Rest, Handler, [[$0]|Stack], Opts);
 value(<<S, Rest/binary>>, Handler, Stack, Opts) when ?is_nonzero(S) ->
-    integer(Rest, Handler, [?new_seq(S)|Stack], Opts);
+    integer(Rest, Handler, [[S]|Stack], Opts);
 value(<<?start_object, Rest/binary>>, {Handler, State}, Stack, Opts) ->
     object(Rest, {Handler, Handler:handle_event(start_object, State)}, [key|Stack], Opts);
 value(<<?start_array, Rest/binary>>, {Handler, State}, Stack, Opts) ->
@@ -193,11 +193,11 @@ array(<<$f, Rest/binary>>, Handler, Stack, Opts) ->
 array(<<$n, Rest/binary>>, Handler, Stack, Opts) ->
     nu(Rest, Handler, Stack, Opts);
 array(<<?negative, Rest/binary>>, Handler, Stack, Opts) ->
-    negative(Rest, Handler, [?new_seq($-)|Stack], Opts);
+    negative(Rest, Handler, [[$-]|Stack], Opts);
 array(<<?zero, Rest/binary>>, Handler, Stack, Opts) ->
-    zero(Rest, Handler, [?new_seq($0)|Stack], Opts);
+    zero(Rest, Handler, [[$0]|Stack], Opts);
 array(<<S, Rest/binary>>, Handler, Stack, Opts) when ?is_nonzero(S) ->
-    integer(Rest, Handler, [?new_seq(S)|Stack], Opts);
+    integer(Rest, Handler, [[S]|Stack], Opts);
 array(<<?start_object, Rest/binary>>, {Handler, State}, Stack, Opts) ->
     object(Rest, {Handler, Handler:handle_event(start_object, State)}, [key|Stack], Opts);
 array(<<?start_array, Rest/binary>>, {Handler, State}, Stack, Opts) ->
@@ -260,6 +260,12 @@ partial_utf(<<X, Y, Z>>)
 partial_utf(_) -> false.
 
 
+%% explicitly whitelist ascii set for better efficiency (seriously, it's worth
+%%  almost a 20% increase)
+string(<<32, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 32)|Stack], Opts);
+string(<<33, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 33)|Stack], Opts);
 string(<<?doublequote, Rest/binary>>, {Handler, State}, S, Opts) ->
     case S of
         [Acc, key|Stack] ->
@@ -269,6 +275,14 @@ string(<<?doublequote, Rest/binary>>, {Handler, State}, S, Opts) ->
         [Acc|Stack] ->
             maybe_done(Rest, {Handler, Handler:handle_event({string, ?end_seq(Acc)}, State)}, Stack, Opts)
     end;
+string(<<35, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 35)|Stack], Opts);
+string(<<36, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 36)|Stack], Opts);
+string(<<37, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 37)|Stack], Opts);
+string(<<38, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 38)|Stack], Opts);
 string(<<?singlequote, Rest/binary>>, {Handler, State}, S, Opts = #opts{single_quotes=true}) ->
     case S of
         [Acc, single_quote, key|Stack] ->
@@ -278,37 +292,183 @@ string(<<?singlequote, Rest/binary>>, {Handler, State}, S, Opts = #opts{single_q
         [Acc|Stack] ->
             string(Rest, {Handler, State}, [?acc_seq(Acc, ?singlequote)|Stack], Opts)
     end;
+string(<<40, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 40)|Stack], Opts);
+string(<<41, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 41)|Stack], Opts);
+string(<<42, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 42)|Stack], Opts);
+string(<<43, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 43)|Stack], Opts);
+string(<<44, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 44)|Stack], Opts);
+string(<<45, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 45)|Stack], Opts);
+string(<<46, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 46)|Stack], Opts);
+string(<<47, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 47)|Stack], Opts);
+string(<<48, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 48)|Stack], Opts);
+string(<<49, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 49)|Stack], Opts);
+string(<<50, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 50)|Stack], Opts);
+string(<<51, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 51)|Stack], Opts);
+string(<<52, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 52)|Stack], Opts);
+string(<<53, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 53)|Stack], Opts);
+string(<<54, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 54)|Stack], Opts);
+string(<<55, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 55)|Stack], Opts);
+string(<<56, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 56)|Stack], Opts);
+string(<<57, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 57)|Stack], Opts);
+string(<<58, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 58)|Stack], Opts);
+string(<<59, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 59)|Stack], Opts);
+string(<<60, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 60)|Stack], Opts);
+string(<<61, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 61)|Stack], Opts);
+string(<<62, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 62)|Stack], Opts);
+string(<<63, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 63)|Stack], Opts);
+string(<<64, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 64)|Stack], Opts);
+string(<<65, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 65)|Stack], Opts);
+string(<<66, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 66)|Stack], Opts);
+string(<<67, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 67)|Stack], Opts);
+string(<<68, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 68)|Stack], Opts);
+string(<<69, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 69)|Stack], Opts);
+string(<<70, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 70)|Stack], Opts);
+string(<<71, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 71)|Stack], Opts);
+string(<<72, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 72)|Stack], Opts);
+string(<<73, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 73)|Stack], Opts);
+string(<<74, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 74)|Stack], Opts);
+string(<<75, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 75)|Stack], Opts);
+string(<<76, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 76)|Stack], Opts);
+string(<<77, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 77)|Stack], Opts);
+string(<<78, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 78)|Stack], Opts);
+string(<<79, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 79)|Stack], Opts);
+string(<<80, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 80)|Stack], Opts);
+string(<<81, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 81)|Stack], Opts);
+string(<<82, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 82)|Stack], Opts);
+string(<<83, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 83)|Stack], Opts);
+string(<<84, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 84)|Stack], Opts);
+string(<<85, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 85)|Stack], Opts);
+string(<<86, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 86)|Stack], Opts);
+string(<<87, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 87)|Stack], Opts);
+string(<<88, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 88)|Stack], Opts);
+string(<<89, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 89)|Stack], Opts);
+string(<<90, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 90)|Stack], Opts);
+string(<<91, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 91)|Stack], Opts);
 string(<<?rsolidus/utf8, Rest/binary>>, Handler, Stack, Opts) ->
     escape(Rest, Handler, Stack, Opts);
-%% things get dumb here. erlang doesn't properly restrict unicode non-characters
-%%   so you can't trust the codepoints it returns always
-%% the range 32..16#fdcf is safe, so allow that
-string(<<S/utf8, Rest/binary>>, Handler, [Acc|Stack], Opts)
-        when ?is_noncontrol(S), S < 16#fdd0 ->
-    string(Rest, Handler, [?acc_seq(Acc, S)|Stack], Opts);
-%% the range 16#fdf0..16#fffd is also safe
-string(<<S/utf8, Rest/binary>>, Handler, [Acc|Stack], Opts)
-        when S > 16#fdef, S < 16#fffe ->
-    string(Rest, Handler, [?acc_seq(Acc, S)|Stack], Opts);
-%% yes, i think it's insane too
-string(<<S/utf8, Rest/binary>>, Handler, [Acc|Stack], Opts)
-        when S > 16#ffff andalso
-            S =/= 16#1fffe andalso S =/= 16#1ffff andalso
-            S =/= 16#2fffe andalso S =/= 16#2ffff andalso
-            S =/= 16#3fffe andalso S =/= 16#3ffff andalso
-            S =/= 16#4fffe andalso S =/= 16#4ffff andalso
-            S =/= 16#5fffe andalso S =/= 16#5ffff andalso
-            S =/= 16#6fffe andalso S =/= 16#6ffff andalso
-            S =/= 16#7fffe andalso S =/= 16#7ffff andalso
-            S =/= 16#8fffe andalso S =/= 16#8ffff andalso
-            S =/= 16#9fffe andalso S =/= 16#9ffff andalso
-            S =/= 16#afffe andalso S =/= 16#affff andalso
-            S =/= 16#bfffe andalso S =/= 16#bffff andalso
-            S =/= 16#cfffe andalso S =/= 16#cffff andalso
-            S =/= 16#dfffe andalso S =/= 16#dffff andalso
-            S =/= 16#efffe andalso S =/= 16#effff andalso
-            S =/= 16#ffffe andalso S =/= 16#fffff andalso
-            S =/= 16#10fffe andalso S =/= 16#10ffff ->
+string(<<93, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 93)|Stack], Opts);
+string(<<94, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 94)|Stack], Opts);
+string(<<95, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 95)|Stack], Opts);
+string(<<96, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 96)|Stack], Opts);
+string(<<97, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 97)|Stack], Opts);
+string(<<98, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 98)|Stack], Opts);
+string(<<99, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 99)|Stack], Opts);
+string(<<100, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 100)|Stack], Opts);
+string(<<101, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 101)|Stack], Opts);
+string(<<102, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 102)|Stack], Opts);
+string(<<103, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 103)|Stack], Opts);
+string(<<104, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 104)|Stack], Opts);
+string(<<105, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 105)|Stack], Opts);
+string(<<106, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 106)|Stack], Opts);
+string(<<107, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 107)|Stack], Opts);
+string(<<108, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 108)|Stack], Opts);
+string(<<109, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 109)|Stack], Opts);
+string(<<110, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 110)|Stack], Opts);
+string(<<111, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 111)|Stack], Opts);
+string(<<112, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 112)|Stack], Opts);
+string(<<113, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 113)|Stack], Opts);
+string(<<114, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 114)|Stack], Opts);
+string(<<115, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 115)|Stack], Opts);
+string(<<116, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 116)|Stack], Opts);
+string(<<117, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 117)|Stack], Opts);
+string(<<118, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 118)|Stack], Opts);
+string(<<119, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 119)|Stack], Opts);
+string(<<120, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 120)|Stack], Opts);
+string(<<121, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 121)|Stack], Opts);
+string(<<122, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 122)|Stack], Opts);
+string(<<123, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 123)|Stack], Opts);
+string(<<124, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 124)|Stack], Opts);
+string(<<125, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 125)|Stack], Opts);
+string(<<126, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 126)|Stack], Opts);
+string(<<127, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
+    string(Rest, Handler, [?acc_seq(Acc, 127)|Stack], Opts);
+string(<<S/utf8, Rest/binary>>, Handler, [Acc|Stack], Opts) when ?is_noncontrol(S) ->
     string(Rest, Handler, [?acc_seq(Acc, S)|Stack], Opts);
 string(Bin, Handler, Stack, Opts) ->
     case partial_utf(Bin) of 
@@ -321,35 +481,13 @@ string(Bin, Handler, Stack, Opts) ->
     end.
     
 %% we don't need to guard against partial utf here, because it's already taken
-%%   care of in string. theoretically, the last clause of noncharacter/4 is
-%%   unreachable
-%% non-characters erlang doesn't recognize as non-characters
-noncharacter(<<S/utf8, Rest/binary>>, Handler, [Acc|Stack], Opts)
-        when ?is_noncontrol(S) ->
-    string(Rest, Handler, [?acc_seq(Acc, 16#fffd)|Stack], Opts);
-%% u+fffe and u+ffff
-noncharacter(<<239, 191, X, Rest/binary>>, Handler, [Acc|Stack], Opts) 
-        when X == 190; X == 191 ->
-    string(Rest, Handler, [?acc_seq(Acc, 16#fffd)|Stack], Opts);
+%%   care of in string
 %% surrogates
 noncharacter(<<237, X, _, Rest/binary>>, Handler, [Acc|Stack], Opts) when X >= 160 ->
     string(Rest, Handler, [?acc_seq(Acc, 16#fffd)|Stack], Opts);
-noncharacter(<<X, Y, 191, Z, Rest/binary>>, Handler, [Acc|Stack], Opts)
-        when (
-            (X == 240 andalso Y == 159) orelse
-            (X == 240 andalso Y == 175) orelse
-            (X == 240 andalso Y == 191) orelse
-            (
-                (X == 241 orelse X == 242 orelse X == 243) andalso
-                (Y == 143 orelse Y == 159 orelse Y == 175 orelse Y == 191)
-            ) orelse
-            (X == 244 andalso Y == 143)
-        ) andalso (Z == 190 orelse Z == 191) ->
-    string(Rest, Handler, [?acc_seq(Acc, 16#fffd)|Stack], Opts);
+%% bad utf8
 noncharacter(<<_, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
-    string(Rest, Handler, [?acc_seq(Acc, 16#fffd)|Stack], Opts);
-noncharacter(Bin, Handler, Stack, Opts) ->
-    ?error([Bin, Handler, Stack, Opts]).
+    string(Rest, Handler, [?acc_seq(Acc, 16#fffd)|Stack], Opts).
 
 
 escape(<<$b, Rest/binary>>, Handler, [Acc|Stack], Opts) ->
@@ -1027,7 +1165,6 @@ comments_test_() ->
         )}
     ].
 
-
 escape_forward_slash_test_() ->
     [
         {"escape forward slash test", ?_assertEqual(
@@ -1036,27 +1173,6 @@ escape_forward_slash_test_() ->
         )}
     ].
 
-
-noncharacters_test_() ->
-    [
-        {"noncharacters - badjson",
-            ?_assertEqual(check_bad(noncharacters()), [])
-        },
-        {"noncharacters - replaced",
-            ?_assertEqual(check_replaced(noncharacters()), [])
-        }
-    ].
-
-extended_noncharacters_test_() ->
-    [
-        {"extended noncharacters - badjson",
-            ?_assertEqual(check_bad(extended_noncharacters()), [])
-        },
-        {"extended noncharacters - replaced",
-            ?_assertEqual(check_replaced(extended_noncharacters()), [])
-        }
-    ].
-
 surrogates_test_() ->
     [
         {"surrogates - badjson",
@@ -1073,16 +1189,6 @@ control_test_() ->
             ?_assertEqual(check_bad(control_characters()), [])
         }
     ].
-
-reserved_test_() ->
-    [
-        {"reserved noncharacters - badjson",
-            ?_assertEqual(check_bad(reserved_space()), [])
-        },
-        {"reserved noncharacters - replaced",
-            ?_assertEqual(check_replaced(reserved_space()), [])
-        }
-    ].
     
 good_characters_test_() ->
     [
@@ -1171,34 +1277,15 @@ decode(JSON, Opts) ->
     catch
         error:badarg -> {error, badjson}
     end.
-    
 
 
-noncharacters() -> lists:seq(16#fffe, 16#ffff).
-    
-extended_noncharacters() ->
-    [16#1fffe, 16#1ffff, 16#2fffe, 16#2ffff]
-        ++ [16#3fffe, 16#3ffff, 16#4fffe, 16#4ffff]
-        ++ [16#5fffe, 16#5ffff, 16#6fffe, 16#6ffff]
-        ++ [16#7fffe, 16#7ffff, 16#8fffe, 16#8ffff]
-        ++ [16#9fffe, 16#9ffff, 16#afffe, 16#affff]
-        ++ [16#bfffe, 16#bffff, 16#cfffe, 16#cffff]
-        ++ [16#dfffe, 16#dffff, 16#efffe, 16#effff]
-        ++ [16#ffffe, 16#fffff, 16#10fffe, 16#10ffff].
-
 surrogates() -> lists:seq(16#d800, 16#dfff).
 
 control_characters() -> lists:seq(1, 31).
 
-reserved_space() -> lists:seq(16#fdd0, 16#fdef).
-
-good() -> [32, 33]
-            ++ lists:seq(16#23, 16#5b)
-            ++ lists:seq(16#5d, 16#d7ff)
-            ++ lists:seq(16#e000, 16#fdcf)
-            ++ lists:seq(16#fdf0, 16#fffd).
+good() -> [32, 33] ++ lists:seq(16#23, 16#5b) ++ lists:seq(16#5d, 16#d7ff) ++ lists:seq(16#e000, 16#ffff).
             
-good_extended() -> lists:seq(16#100000, 16#10fffd).
+good_extended() -> lists:seq(16#100000, 16#10ffff).
 
 %% erlang refuses to encode certain codepoints, so fake them all
 to_fake_utf(N, utf8) when N < 16#0080 -> <<34/utf8, N:8, 34/utf8>>;
diff --git a/src/jsx_encoder.erl b/src/jsx_encoder.erl
index 76e9111..1dbd13f 100644
--- a/src/jsx_encoder.erl
+++ b/src/jsx_encoder.erl
@@ -53,7 +53,7 @@ start(Term, {Handler, State}, Opts) ->
 
 
 value(String, {Handler, State}, Opts) when is_binary(String) ->
-    Handler:handle_event({string, clean_string(String, <<>>, Opts)}, State);
+    Handler:handle_event({string, clean_string(String, Opts)}, State);
 value(Float, {Handler, State}, _Opts) when is_float(Float) ->
     Handler:handle_event({float, Float}, State);
 value(Int, {Handler, State}, _Opts) when is_integer(Int) ->
@@ -83,7 +83,7 @@ object([{Key, Value}|Rest], {Handler, State}, Opts) ->
             Handler,
             value(
                 Value,
-                {Handler, Handler:handle_event({key, clean_string(fix_key(Key), <<>>, Opts)}, State)},
+                {Handler, Handler:handle_event({key, clean_string(fix_key(Key), Opts)}, State)},
                 Opts
             )
         },
@@ -103,96 +103,31 @@ fix_key(Key) when is_atom(Key) -> fix_key(atom_to_binary(Key, utf8));
 fix_key(Key) when is_binary(Key) -> Key.
 
 
-clean_string(<<$\", Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, $\\, $\">>, Opts);
-clean_string(<<$\\, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, $\\, $\\>>, Opts);
-clean_string(<<$\b, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, $\\, $b>>, Opts);
-clean_string(<<$\f, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, $\\, $f>>, Opts);
-clean_string(<<$\n, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, $\\, $n>>, Opts);
-clean_string(<<$\r, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, $\\, $r>>, Opts);
-clean_string(<<$\t, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, $\\, $t>>, Opts);
-clean_string(<<$/, Rest/binary>>, Acc, Opts=#opts{json_escape=true, escape_forward_slash=true}) ->
-    clean_string(Rest, <<Acc/binary, $\\, $/>>, Opts);
-clean_string(<<16#2028/utf8, Rest/binary>>, Acc, Opts=#opts{json_escape=true, no_jsonp_escapes=true}) ->
-    clean_string(Rest, <<Acc/binary, 16#2028/utf8>>, Opts);
-clean_string(<<16#2029/utf8, Rest/binary>>, Acc, Opts=#opts{json_escape=true, no_jsonp_escapes=true}) ->
-    clean_string(Rest, <<Acc/binary, 16#2029/utf8>>, Opts);
-clean_string(<<16#2028/utf8, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, (json_escape_sequence(16#2028))/binary>>, Opts);
-clean_string(<<16#2029/utf8, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) ->
-    clean_string(Rest, <<Acc/binary, (json_escape_sequence(16#2029))/binary>>, Opts);
-clean_string(<<C/utf8, Rest/binary>>, Acc, Opts=#opts{json_escape=true}) when C < 32 ->
-    clean_string(Rest, <<Acc/binary, (json_escape_sequence(C))/binary>>, Opts);
-clean_string(<<C/utf8, Rest/binary>>, Acc, Opts) when C < 16#fdd0 ->
-    clean_string(Rest, <<Acc/binary, C/utf8>>, Opts);
-clean_string(<<C/utf8, Rest/binary>>, Acc, Opts) when C > 16#fdef, C < 16#fffe ->
-    clean_string(Rest, <<Acc/binary, C/utf8>>, Opts);
-clean_string(<<C/utf8, Rest/binary>>, Acc, Opts) 
-        when C > 16#ffff andalso
-            C =/= 16#1fffe andalso C =/= 16#1ffff andalso
-            C =/= 16#2fffe andalso C =/= 16#2ffff andalso
-            C =/= 16#3fffe andalso C =/= 16#3ffff andalso
-            C =/= 16#4fffe andalso C =/= 16#4ffff andalso
-            C =/= 16#5fffe andalso C =/= 16#5ffff andalso
-            C =/= 16#6fffe andalso C =/= 16#6ffff andalso
-            C =/= 16#7fffe andalso C =/= 16#7ffff andalso
-            C =/= 16#8fffe andalso C =/= 16#8ffff andalso
-            C =/= 16#9fffe andalso C =/= 16#9ffff andalso
-            C =/= 16#afffe andalso C =/= 16#affff andalso
-            C =/= 16#bfffe andalso C =/= 16#bffff andalso
-            C =/= 16#cfffe andalso C =/= 16#cffff andalso
-            C =/= 16#dfffe andalso C =/= 16#dffff andalso
-            C =/= 16#efffe andalso C =/= 16#effff andalso
-            C =/= 16#ffffe andalso C =/= 16#fffff andalso
-            C =/= 16#10fffe andalso C =/= 16#10ffff ->
-    clean_string(Rest, <<Acc/binary, C/utf8>>, Opts);
+clean_string(Bin, Opts) ->
+    case Opts#opts.json_escape of
+        true -> jsx_utils:json_escape(Bin, Opts);
+        false -> 
+            case is_clean(Bin) of
+                true -> Bin;
+                false -> clean_string(Bin, [], Opts)
+            end
+    end.
+
+
+is_clean(<<>>) -> true;
+is_clean(<<_/utf8, Rest/binary>>) -> is_clean(Rest);
+is_clean(_) -> false.
+
+
+clean_string(Bin, _Acc, Opts=#opts{loose_unicode=false}) -> ?error([Bin, Opts]);
+clean_string(<<>>, Acc, _Opts) -> unicode:characters_to_binary(lists:reverse(Acc));
+clean_string(<<X/utf8, Rest/binary>>, Acc, Opts) -> clean_string(Rest, [X] ++ Acc, Opts);
 %% surrogates
-clean_string(<<237, X, _, Rest/binary>>, Acc, Opts=#opts{loose_unicode=true}) when X >= 160 ->
-    clean_string(Rest, <<Acc/binary, 16#fffd/utf8>>, Opts);
-%% private use noncharacters
-clean_string(<<239, 183, X, Rest/binary>>, Acc, Opts=#opts{loose_unicode=true}) when X >= 143, X =< 175 ->
-    clean_string(Rest, <<Acc/binary, 16#fffd/utf8>>, Opts);
-%% u+fffe and u+ffff
-clean_string(<<239, 191, X, Rest/binary>>, Acc, Opts=#opts{loose_unicode=true}) when X == 190; X == 191 ->
-    clean_string(Rest, <<Acc/binary, 16#fffd/utf8>>, Opts);
-%% the u+Xfffe and u+Xffff noncharacters
-clean_string(<<X, Y, 191, Z, Rest/binary>>, Acc, Opts=#opts{loose_unicode=true}) when (
-            (X == 240 andalso Y == 159) orelse
-            (X == 240 andalso Y == 175) orelse
-            (X == 240 andalso Y == 191) orelse
-            (
-                (X == 241 orelse X == 242 orelse X == 243) andalso
-                (Y == 143 orelse Y == 159 orelse Y == 175 orelse Y == 191)
-            ) orelse
-            (X == 244 andalso Y == 143)
-        ) andalso (Z == 190 orelse Z == 191) ->
-    clean_string(Rest, <<Acc/binary, 16#fffd/utf8>>, Opts);
-clean_string(<<_, Rest/binary>>, Acc, Opts=#opts{loose_unicode=true}) ->
-    clean_string(Rest, <<Acc/binary, 16#fffd/utf8>>, Opts);
-clean_string(<<>>, Acc, _) -> Acc;
-clean_string(Bin, _Acc, Opts) -> erlang:error(badarg, [Bin, Opts]).
-    
-    
-%% convert a codepoint to it's \uXXXX equiv.
-json_escape_sequence(X) ->
-    <<A:4, B:4, C:4, D:4>> = <<X:16>>,
-    unicode:characters_to_binary([$\\, $u, (to_hex(A)), (to_hex(B)), (to_hex(C)), (to_hex(D))]).
+clean_string(<<237, X, _, Rest/binary>>, Acc, Opts) when X >= 160 -> clean_string(Rest, [16#fffd] ++ Acc, Opts);
+%% bad codepoints
+clean_string(<<_, Rest/binary>>, Acc, Opts) -> clean_string(Rest, [16#fffd] ++ Acc, Opts).
 
 
-to_hex(10) -> $a;
-to_hex(11) -> $b;
-to_hex(12) -> $c;
-to_hex(13) -> $d;
-to_hex(14) -> $e;
-to_hex(15) -> $f;
-to_hex(X) -> X + 48.    %% ascii "1" is [49], "2" is [50], etc...
-
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").
 
@@ -274,26 +209,6 @@ encode_test_() ->
             )
         }
     ].
-    
-noncharacters_test_() ->
-    [
-        {"noncharacters - badjson",
-            ?_assertEqual(check_bad(noncharacters()), [])
-        },
-        {"noncharacters - replaced",
-            ?_assertEqual(check_replaced(noncharacters()), [])
-        }
-    ].
-
-extended_noncharacters_test_() ->
-    [
-        {"extended noncharacters - badjson",
-            ?_assertEqual(check_bad(extended_noncharacters()), [])
-        },
-        {"extended noncharacters - replaced",
-            ?_assertEqual(check_replaced(extended_noncharacters()), [])
-        }
-    ].
 
 surrogates_test_() ->
     [
@@ -304,16 +219,6 @@ surrogates_test_() ->
             ?_assertEqual(check_replaced(surrogates()), [])
         }
     ].
-
-reserved_test_() ->
-    [
-        {"reserved noncharacters - badjson",
-            ?_assertEqual(check_bad(reserved_space()), [])
-        },
-        {"reserved noncharacters - replaced",
-            ?_assertEqual(check_replaced(reserved_space()), [])
-        }
-    ].
     
 good_characters_test_() ->
     [
@@ -385,26 +290,11 @@ check([H|T], Opts, Acc) ->
     check(T, Opts, [{H, R}] ++ Acc).
     
 
-
-noncharacters() -> lists:seq(16#fffe, 16#ffff).
-    
-extended_noncharacters() ->
-    [16#1fffe, 16#1ffff, 16#2fffe, 16#2ffff]
-        ++ [16#3fffe, 16#3ffff, 16#4fffe, 16#4ffff]
-        ++ [16#5fffe, 16#5ffff, 16#6fffe, 16#6ffff]
-        ++ [16#7fffe, 16#7ffff, 16#8fffe, 16#8ffff]
-        ++ [16#9fffe, 16#9ffff, 16#afffe, 16#affff]
-        ++ [16#bfffe, 16#bffff, 16#cfffe, 16#cffff]
-        ++ [16#dfffe, 16#dffff, 16#efffe, 16#effff]
-        ++ [16#ffffe, 16#fffff, 16#10fffe, 16#10ffff].
-
 surrogates() -> lists:seq(16#d800, 16#dfff).
 
-reserved_space() -> lists:seq(16#fdd0, 16#fdef).
-
-good() -> lists:seq(1, 16#d7ff) ++ lists:seq(16#e000, 16#fdcf) ++ lists:seq(16#fdf0, 16#fffd).
+good() -> lists:seq(1, 16#d7ff) ++ lists:seq(16#e000, 16#ffff).
             
-good_extended() -> lists:seq(16#100000, 16#10fffd).
+good_extended() -> lists:seq(16#100000, 16#10ffff).
 
 %% erlang refuses to encode certain codepoints, so fake them all
 to_fake_utf(N, utf8) when N < 16#0080 -> <<N:8>>;
diff --git a/src/jsx_utils.erl b/src/jsx_utils.erl
index f9970ee..462e31d 100644
--- a/src/jsx_utils.erl
+++ b/src/jsx_utils.erl
@@ -90,22 +90,66 @@ extract_parser_opts([K|Rest], Acc) ->
 json_escape(String, Opts) when is_binary(String) ->
     json_escape(String, Opts, 0, size(String)).
 
+
+-define(control_character(X),
+        <<H:L/binary, X, T/binary>> ->
+            json_escape(
+                <<H/binary, (unicode:characters_to_binary(json_escape_sequence(X)))/binary, T/binary>>,
+                Opts,
+                L + 6,
+                Len + 5
+            )
+).
+
 json_escape(Str, Opts, L, Len) when L < Len ->
     case Str of
-        <<H:L/binary, $\", T/binary>> -> %"  
-            json_escape(<<H/binary, $\\, $", T/binary>>, Opts, L + 2, Len + 1);
-        <<H:L/binary, $\\, T/binary>> ->
-            json_escape(<<H/binary, $\\, $\\, T/binary>>, Opts, L + 2, Len + 1);
-        <<H:L/binary, $\b, T/binary>> ->
-            json_escape(<<H/binary, $\\, $b, T/binary>>, Opts, L + 2, Len + 1);
-        <<H:L/binary, $\f, T/binary>> ->
-            json_escape(<<H/binary, $\\, $f, T/binary>>, Opts, L + 2, Len + 1);
-        <<H:L/binary, $\n, T/binary>> ->
-            json_escape(<<H/binary, $\\, $n, T/binary>>, Opts, L + 2, Len + 1); 
-        <<H:L/binary, $\r, T/binary>> ->
-            json_escape(<<H/binary, $\\, $r, T/binary>>, Opts, L + 2, Len + 1); 
-        <<H:L/binary, $\t, T/binary>> ->
-            json_escape(<<H/binary, $\\, $t, T/binary>>, Opts, L + 2, Len + 1);
+        ?control_character(0);
+        ?control_character(1);
+        ?control_character(2);
+        ?control_character(3);
+        ?control_character(4);
+        ?control_character(5);
+        ?control_character(6);
+        ?control_character(7);
+        <<H:L/binary, $\b, T/binary>> -> json_escape(<<H/binary, $\\, $b, T/binary>>, Opts, L + 2, Len + 1);
+        <<H:L/binary, $\t, T/binary>> -> json_escape(<<H/binary, $\\, $t, T/binary>>, Opts, L + 2, Len + 1);
+        <<H:L/binary, $\n, T/binary>> -> json_escape(<<H/binary, $\\, $n, T/binary>>, Opts, L + 2, Len + 1);
+        ?control_character(11);
+        <<H:L/binary, $\f, T/binary>> -> json_escape(<<H/binary, $\\, $f, T/binary>>, Opts, L + 2, Len + 1);
+        <<H:L/binary, $\r, T/binary>> -> json_escape(<<H/binary, $\\, $r, T/binary>>, Opts, L + 2, Len + 1);
+        ?control_character(14);
+        ?control_character(15);
+        ?control_character(16);
+        ?control_character(17);
+        ?control_character(18);
+        ?control_character(19);
+        ?control_character(20);
+        ?control_character(21);
+        ?control_character(22);
+        ?control_character(23);
+        ?control_character(24);
+        ?control_character(25);
+        ?control_character(26);
+        ?control_character(27);
+        ?control_character(28);
+        ?control_character(29);
+        ?control_character(30);
+        ?control_character(31);
+        <<_:L/binary, 32, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 33, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<H:L/binary, $\", T/binary>> -> json_escape(<<H/binary, $\\, $", T/binary>>, Opts, L + 2, Len + 1);
+        <<_:L/binary, 35, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 36, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 37, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 38, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 39, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 40, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 41, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 42, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 43, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 44, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 45, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 46, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
         <<H:L/binary, $/, T/binary>> ->
             case Opts#opts.escape_forward_slash of
                 true ->
@@ -113,6 +157,86 @@ json_escape(Str, Opts, L, Len) when L < Len ->
                 false ->
                     json_escape(<<H/binary, $/, T/binary>>, Opts, L + 1, Len)
             end;
+        <<_:L/binary, 48, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 49, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 50, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 51, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 52, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 53, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 54, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 55, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 56, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 57, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 58, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 59, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 60, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 61, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 62, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 63, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 64, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 65, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 66, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 67, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 68, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 69, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 70, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 71, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 72, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 73, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 74, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 75, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 76, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 77, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 78, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 79, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 80, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 81, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 82, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 83, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 84, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 85, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 86, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 87, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 88, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 89, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 90, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 91, _/binary>> -> json_escape(Str, Opts, L + 1, Len);       
+        <<H:L/binary, $\\, T/binary>> -> json_escape(<<H/binary, $\\, $\\, T/binary>>, Opts, L + 2, Len + 1);
+        <<_:L/binary, 93, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 94, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 95, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 96, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 97, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 98, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 99, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 100, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 101, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 102, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 103, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 104, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 105, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 106, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 107, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 108, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 109, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 110, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 111, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 112, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 113, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 114, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 115, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 116, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 117, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 118, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 119, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 120, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 121, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 122, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 123, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 124, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 125, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 126, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
+        <<_:L/binary, 127, _/binary>> -> json_escape(Str, Opts, L + 1, Len);
         <<H:L/binary, 16#2028/utf8, T/binary>> ->
             case Opts#opts.no_jsonp_escapes of
                 true ->
@@ -129,9 +253,6 @@ json_escape(Str, Opts, L, Len) when L < Len ->
                     B = unicode:characters_to_binary(json_escape_sequence(16#2029)),
                     json_escape(<<H/binary, B/binary, T/binary>>, Opts, L + size(B), Len + size(B) - size(<<16#2029/utf8>>))
             end;
-        <<H:L/binary, X/utf8, T/binary>> when X < 32 ->
-            B = unicode:characters_to_binary(json_escape_sequence(X)),
-            json_escape(<<H/binary, B/binary, T/binary>>, Opts, L + size(B), Len + size(B) - size(<<X/utf8>>));
         <<_:L/binary, X/utf8, _/binary>> when X < 16#0080 ->   
             json_escape(Str, Opts, L + 1, Len);
         <<_:L/binary, X/utf8, _/binary>> when X < 16#0800 ->
@@ -140,8 +261,16 @@ json_escape(Str, Opts, L, Len) when L < Len ->
             json_escape(Str, Opts, L + 3, Len);
         <<_:L/binary, _/utf8, _/binary>> ->
             json_escape(Str, Opts, L + 4, Len);
-        <<H:L/binary, X, T/binary>> ->
-            erlang:error(badarg, [[<<H:L/binary, X, T/binary>>, Opts]])            
+        <<H:L/binary, 237, X, _, T/binary>> when X >= 160 ->
+            case Opts#opts.loose_unicode of
+                true -> json_escape(<<H/binary, 16#fffd/utf8, T/binary>>, Opts, L + 3, Len);
+                false -> erlang:error(badarg, [Str, Opts])
+            end;
+        <<H:L/binary, _, T/binary>> ->
+            case Opts#opts.loose_unicode of
+                true -> json_escape(<<H/binary, 16#fffd/utf8, T/binary>>, Opts, L + 3, Len + 2);
+                false -> erlang:error(badarg, [Str, Opts])
+            end            
     end;
 json_escape(Str, _, L, Len) when L =:= Len ->
     Str.
@@ -201,7 +330,20 @@ binary_escape_test_() ->
             )
         },
         {"bad utf8",
-            ?_assertError(badarg, json_escape(<<32, 64, 128, 256>>, #opts{}))
+            ?_assertError(badarg, json_escape(<<32, 64, 128, 255>>, #opts{}))
+        },
+        {"bad utf8 ok",
+            ?_assertEqual(
+                json_escape(<<32, 64, 128, 255>>, #opts{loose_unicode=true}),
+                <<32, 64, 16#fffd/utf8, 16#fffd/utf8>>
+            )
+        },
+        {"bad surrogate", ?_assertError(badarg, json_escape(<<237, 160, 127>>, #opts{}))},
+        {"bad surrogate ok",
+            ?_assertEqual(
+                json_escape(<<237, 160, 127>>, #opts{loose_unicode=true}),
+                <<16#fffd/utf8>>
+            )
         },
         {"all sizes of codepoints",
             ?_assertEqual(