diff --git a/ast/api_amd64.go b/ast/api_amd64.go
index 4631746ed..cd2ae21a7 100644
--- a/ast/api_amd64.go
+++ b/ast/api_amd64.go
@@ -171,3 +171,25 @@ func DecodeString(src string, pos int) (ret int, v string) {
 		return -int(_ERR_UNSUPPORT_TYPE), ""
 	}
 }
+
+// ValidSyntax check if a json has a valid JSON syntax,
+// while not validate UTF-8 charset
+func ValidSyntax(json string) bool {
+	fsm := types.NewStateMachine()
+    p := 0
+    ret := native.ValidateOne(&json, &p, fsm, 0)
+    types.FreeStateMachine(fsm)
+
+     if ret < 0 {
+        return false
+    }
+
+    /* check for trailing spaces */
+    for ;p < len(json); p++ {
+        if !isSpace(json[p]) {
+            return false
+        }
+    }
+
+    return true
+}
diff --git a/ast/api_compat.go b/ast/api_compat.go
index 0ee3d4bca..45ee732d4 100644
--- a/ast/api_compat.go
+++ b/ast/api_compat.go
@@ -136,3 +136,20 @@ func DecodeString(src string, pos int) (ret int, v string) {
     runtime.KeepAlive(src)
     return ret, rt.Mem2Str(vv)
 }
+
+// ValidSyntax check if a json has a valid JSON syntax,
+// while not validate UTF-8 charset
+func ValidSyntax(json string) bool {
+	p, _ := skipValue(json, 0)
+    if p < 0 {
+        return false
+    }
+    /* check for trailing spaces */
+    for ;p < len(json); p++ {
+        if !isSpace(json[p]) {
+            return false
+        }
+    }
+
+    return true
+}
diff --git a/ast/parser.go b/ast/parser.go
index 3debf60cc..0d41d47ee 100644
--- a/ast/parser.go
+++ b/ast/parser.go
@@ -781,6 +781,8 @@ func (self Parser) ExportError(err types.ParsingError) error {
 	}.Description())
 }
 
+// SkipFast skip a json value in fast-skip algs, 
+// while not strictly validate JSON syntax and UTF-8 charset.
 func SkipFast(src string, i int) (int, int, error) {
     p := NewParserObj(src)
     p.p = i
diff --git a/internal/encoder/encoder.go b/internal/encoder/encoder.go
index 0a46455eb..d285c2991 100644
--- a/internal/encoder/encoder.go
+++ b/internal/encoder/encoder.go
@@ -337,7 +337,7 @@ func Valid(data []byte) (ok bool, start int) {
     s := rt.Mem2Str(data)
     p := 0
     m := types.NewStateMachine()
-    ret := native.ValidateOne(&s, &p, m)
+    ret := native.ValidateOne(&s, &p, m, types.F_VALIDATE_STRING)
     types.FreeStateMachine(m)
 
     if ret < 0 {
diff --git a/internal/native/avx/native_amd64.go b/internal/native/avx/native_amd64.go
index 627ac177c..b48e78d6a 100644
--- a/internal/native/avx/native_amd64.go
+++ b/internal/native/avx/native_amd64.go
@@ -64,7 +64,7 @@ var (
 
     __skip_number func(s unsafe.Pointer, p unsafe.Pointer) (ret int)
 
-    __validate_one func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer) (ret int)
+    __validate_one func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer, flags uint64) (ret int)
 
     __get_by_path func(s unsafe.Pointer, p unsafe.Pointer, path unsafe.Pointer, m unsafe.Pointer) (ret int)
 
@@ -166,8 +166,8 @@ func skip_number(s *string, p *int) (ret int) {
 }
 
 //go:nosplit
-func validate_one(s *string, p *int, m *types.StateMachine) (ret int) {
-    return __validate_one(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)))
+func validate_one(s *string, p *int, m *types.StateMachine, flags uint64) (ret int) {
+    return __validate_one(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)), flags)
 }
 
 //go:nosplit
diff --git a/internal/native/avx/native_subr_amd64.go b/internal/native/avx/native_subr_amd64.go
index 50ae487b4..c092cde39 100644
--- a/internal/native/avx/native_subr_amd64.go
+++ b/internal/native/avx/native_subr_amd64.go
@@ -387,8 +387,8 @@ var (
     }
     _pcsp__validate_one = [][2]uint32{
         {1, 0},
-        {35, 8},
-        {41, 0},
+        {30, 8},
+        {36, 0},
     }
     _pcsp__validate_utf8 = [][2]uint32{
         {1, 0},
diff --git a/internal/native/avx/native_text_amd64.go b/internal/native/avx/native_text_amd64.go
index f3d4a4f7a..256f4062d 100644
--- a/internal/native/avx/native_text_amd64.go
+++ b/internal/native/avx/native_text_amd64.go
@@ -5853,14 +5853,13 @@ var Text__native_entry__ = []byte{
 	0x48, 0x89, 0xd0, //0x000055f4 movq         %rdx, %rax
 	0x48, 0x89, 0xf2, //0x000055f7 movq         %rsi, %rdx
 	0x48, 0x89, 0xfe, //0x000055fa movq         %rdi, %rsi
-	0xb9, 0x01, 0x00, 0x00, 0x00, //0x000055fd movl         $1, %ecx
-	0xc4, 0xe1, 0xf9, 0x6e, 0xc1, //0x00005602 vmovq        %rcx, %xmm0
+	0xbf, 0x01, 0x00, 0x00, 0x00, //0x000055fd movl         $1, %edi
+	0xc4, 0xe1, 0xf9, 0x6e, 0xc7, //0x00005602 vmovq        %rdi, %xmm0
 	0xc5, 0xfa, 0x7f, 0x00, //0x00005607 vmovdqu      %xmm0, (%rax)
-	0xb9, 0x20, 0x00, 0x00, 0x00, //0x0000560b movl         $32, %ecx
-	0x48, 0x89, 0xc7, //0x00005610 movq         %rax, %rdi
-	0x5d, //0x00005613 popq         %rbp
-	0xe9, 0xe7, 0xef, 0xff, 0xff, //0x00005614 jmp          _fsm_exec
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //0x00005619 .p2align 4, 0x00
+	0x48, 0x89, 0xc7, //0x0000560b movq         %rax, %rdi
+	0x5d, //0x0000560e popq         %rbp
+	0xe9, 0xec, 0xef, 0xff, 0xff, //0x0000560f jmp          _fsm_exec
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //0x00005614 .p2align 4, 0x00
 	//0x00005620 LCPI27_0
 	0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, //0x00005620 QUAD $0x2c2c2c2c2c2c2c2c; QUAD $0x2c2c2c2c2c2c2c2c  // .space 16, ',,,,,,,,,,,,,,,,'
 	//0x00005630 LCPI27_1
diff --git a/internal/native/avx2/native_amd64.go b/internal/native/avx2/native_amd64.go
index 1a4ea0ae3..3229b885b 100644
--- a/internal/native/avx2/native_amd64.go
+++ b/internal/native/avx2/native_amd64.go
@@ -64,7 +64,7 @@ var (
 
     __skip_number func(s unsafe.Pointer, p unsafe.Pointer) (ret int)
 
-    __validate_one func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer) (ret int)
+    __validate_one func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer, flags uint64) (ret int)
 
     __get_by_path func(s unsafe.Pointer, p unsafe.Pointer, path unsafe.Pointer, m unsafe.Pointer) (ret int)
 
@@ -166,8 +166,8 @@ func skip_number(s *string, p *int) (ret int) {
 }
 
 //go:nosplit
-func validate_one(s *string, p *int, m *types.StateMachine) (ret int) {
-    return __validate_one(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)))
+func validate_one(s *string, p *int, m *types.StateMachine, flags uint64) (ret int) {
+    return __validate_one(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)), flags)
 }
 
 //go:nosplit
diff --git a/internal/native/avx2/native_subr_amd64.go b/internal/native/avx2/native_subr_amd64.go
index 432aea923..679118fc3 100644
--- a/internal/native/avx2/native_subr_amd64.go
+++ b/internal/native/avx2/native_subr_amd64.go
@@ -395,8 +395,8 @@ var (
     }
     _pcsp__validate_one = [][2]uint32{
         {1, 0},
-        {35, 8},
-        {41, 0},
+        {30, 8},
+        {36, 0},
     }
     _pcsp__validate_utf8 = [][2]uint32{
         {1, 0},
diff --git a/internal/native/avx2/native_text_amd64.go b/internal/native/avx2/native_text_amd64.go
index 628e492b2..43a6f39bd 100644
--- a/internal/native/avx2/native_text_amd64.go
+++ b/internal/native/avx2/native_text_amd64.go
@@ -6702,14 +6702,13 @@ var Text__native_entry__ = []byte{
 	0x48, 0x89, 0xd0, //0x00006404 movq         %rdx, %rax
 	0x48, 0x89, 0xf2, //0x00006407 movq         %rsi, %rdx
 	0x48, 0x89, 0xfe, //0x0000640a movq         %rdi, %rsi
-	0xb9, 0x01, 0x00, 0x00, 0x00, //0x0000640d movl         $1, %ecx
-	0xc4, 0xe1, 0xf9, 0x6e, 0xc1, //0x00006412 vmovq        %rcx, %xmm0
+	0xbf, 0x01, 0x00, 0x00, 0x00, //0x0000640d movl         $1, %edi
+	0xc4, 0xe1, 0xf9, 0x6e, 0xc7, //0x00006412 vmovq        %rdi, %xmm0
 	0xc5, 0xfa, 0x7f, 0x00, //0x00006417 vmovdqu      %xmm0, (%rax)
-	0xb9, 0x20, 0x00, 0x00, 0x00, //0x0000641b movl         $32, %ecx
-	0x48, 0x89, 0xc7, //0x00006420 movq         %rax, %rdi
-	0x5d, //0x00006423 popq         %rbp
-	0xe9, 0x27, 0xee, 0xff, 0xff, //0x00006424 jmp          _fsm_exec
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //0x00006429 .p2align 5, 0x00
+	0x48, 0x89, 0xc7, //0x0000641b movq         %rax, %rdi
+	0x5d, //0x0000641e popq         %rbp
+	0xe9, 0x2c, 0xee, 0xff, 0xff, //0x0000641f jmp          _fsm_exec
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //0x00006424 .p2align 5, 0x00
 	//0x00006440 LCPI28_0
 	0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, //0x00006440 QUAD $0x2c2c2c2c2c2c2c2c; QUAD $0x2c2c2c2c2c2c2c2c  // .space 16, ',,,,,,,,,,,,,,,,'
 	0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, //0x00006450 QUAD $0x2c2c2c2c2c2c2c2c; QUAD $0x2c2c2c2c2c2c2c2c  // .space 16, ',,,,,,,,,,,,,,,,'
diff --git a/internal/native/dispatch_amd64.go b/internal/native/dispatch_amd64.go
index 474badebb..84bd61fe5 100644
--- a/internal/native/dispatch_amd64.go
+++ b/internal/native/dispatch_amd64.go
@@ -85,7 +85,7 @@ var (
 
     __GetByPath func(s unsafe.Pointer, p unsafe.Pointer, path unsafe.Pointer, m unsafe.Pointer) int
     
-    __ValidateOne func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer) int
+    __ValidateOne func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer, flags uint64) int
 
     __I64toa func(out unsafe.Pointer, val int64) (ret int)
 
@@ -134,8 +134,8 @@ func GetByPath(s *string, p *int, path *[]interface{}, m *types.StateMachine) in
 }
 
 //go:nosplit
-func ValidateOne(s *string, p *int, m *types.StateMachine) int {
-    return __ValidateOne(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)))
+func ValidateOne(s *string, p *int, m *types.StateMachine, flags uint64) int {
+    return __ValidateOne(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)), flags)
 }
 
 //go:nosplit
diff --git a/internal/native/native_amd64.tmpl b/internal/native/native_amd64.tmpl
index 5839da99c..bfec62aa9 100644
--- a/internal/native/native_amd64.tmpl
+++ b/internal/native/native_amd64.tmpl
@@ -62,7 +62,7 @@ var (
 
     __skip_number func(s unsafe.Pointer, p unsafe.Pointer) (ret int)
 
-    __validate_one func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer) (ret int)
+    __validate_one func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer, flags uint64) (ret int)
 
     __get_by_path func(s unsafe.Pointer, p unsafe.Pointer, path unsafe.Pointer, m unsafe.Pointer) (ret int)
 
@@ -164,8 +164,8 @@ func skip_number(s *string, p *int) (ret int) {
 }
 
 //go:nosplit
-func validate_one(s *string, p *int, m *types.StateMachine) (ret int) {
-    return __validate_one(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)))
+func validate_one(s *string, p *int, m *types.StateMachine, flags uint64) (ret int) {
+    return __validate_one(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)), flags)
 }
 
 //go:nosplit
diff --git a/internal/native/sse/native_amd64.go b/internal/native/sse/native_amd64.go
index c2ab79531..74903e9e1 100644
--- a/internal/native/sse/native_amd64.go
+++ b/internal/native/sse/native_amd64.go
@@ -64,7 +64,7 @@ var (
 
     __skip_number func(s unsafe.Pointer, p unsafe.Pointer) (ret int)
 
-    __validate_one func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer) (ret int)
+    __validate_one func(s unsafe.Pointer, p unsafe.Pointer, m unsafe.Pointer, flags uint64) (ret int)
 
     __get_by_path func(s unsafe.Pointer, p unsafe.Pointer, path unsafe.Pointer, m unsafe.Pointer) (ret int)
 
@@ -166,8 +166,8 @@ func skip_number(s *string, p *int) (ret int) {
 }
 
 //go:nosplit
-func validate_one(s *string, p *int, m *types.StateMachine) (ret int) {
-    return __validate_one(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)))
+func validate_one(s *string, p *int, m *types.StateMachine, flags uint64) (ret int) {
+    return __validate_one(rt.NoEscape(unsafe.Pointer(s)), rt.NoEscape(unsafe.Pointer(p)), rt.NoEscape(unsafe.Pointer(m)), flags)
 }
 
 //go:nosplit
diff --git a/internal/native/sse/native_subr_amd64.go b/internal/native/sse/native_subr_amd64.go
index 8c0c2d04e..2c7245929 100644
--- a/internal/native/sse/native_subr_amd64.go
+++ b/internal/native/sse/native_subr_amd64.go
@@ -388,8 +388,8 @@ var (
     }
     _pcsp__validate_one = [][2]uint32{
         {1, 0},
-        {35, 8},
-        {41, 0},
+        {30, 8},
+        {36, 0},
     }
     _pcsp__validate_utf8 = [][2]uint32{
         {1, 0},
diff --git a/internal/native/sse/native_text_amd64.go b/internal/native/sse/native_text_amd64.go
index 7a155f945..0a55d63b9 100644
--- a/internal/native/sse/native_text_amd64.go
+++ b/internal/native/sse/native_text_amd64.go
@@ -5898,14 +5898,13 @@ var Text__native_entry__ = []byte{
 	0x48, 0x89, 0xd0, //0x00005664 movq         %rdx, %rax
 	0x48, 0x89, 0xf2, //0x00005667 movq         %rsi, %rdx
 	0x48, 0x89, 0xfe, //0x0000566a movq         %rdi, %rsi
-	0xb9, 0x01, 0x00, 0x00, 0x00, //0x0000566d movl         $1, %ecx
-	0x66, 0x48, 0x0f, 0x6e, 0xc1, //0x00005672 movq         %rcx, %xmm0
+	0xbf, 0x01, 0x00, 0x00, 0x00, //0x0000566d movl         $1, %edi
+	0x66, 0x48, 0x0f, 0x6e, 0xc7, //0x00005672 movq         %rdi, %xmm0
 	0xf3, 0x0f, 0x7f, 0x00, //0x00005677 movdqu       %xmm0, (%rax)
-	0xb9, 0x20, 0x00, 0x00, 0x00, //0x0000567b movl         $32, %ecx
-	0x48, 0x89, 0xc7, //0x00005680 movq         %rax, %rdi
-	0x5d, //0x00005683 popq         %rbp
-	0xe9, 0xd7, 0xef, 0xff, 0xff, //0x00005684 jmp          _fsm_exec
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //0x00005689 .p2align 4, 0x00
+	0x48, 0x89, 0xc7, //0x0000567b movq         %rax, %rdi
+	0x5d, //0x0000567e popq         %rbp
+	0xe9, 0xdc, 0xef, 0xff, 0xff, //0x0000567f jmp          _fsm_exec
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //0x00005684 .p2align 4, 0x00
 	//0x00005690 LCPI27_0
 	0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, //0x00005690 QUAD $0x2c2c2c2c2c2c2c2c; QUAD $0x2c2c2c2c2c2c2c2c  // .space 16, ',,,,,,,,,,,,,,,,'
 	//0x000056a0 LCPI27_1
diff --git a/native/native.h b/native/native.h
index 93d55dc4d..fd655deff 100644
--- a/native/native.h
+++ b/native/native.h
@@ -145,7 +145,7 @@ bool atof_eisel_lemire64(uint64_t mant, int exp10, int sgn, double *val);
 double atof_native(const char *sp, ssize_t nb, char *dbuf, ssize_t cap);
 
 long validate_string(const GoString *src, long *p);
-long validate_one(const GoString *src, long *p, StateMachine *m);
+long validate_one(const GoString *src, long *p, StateMachine *m, uint64_t flags);
 long validate_utf8(const GoString *src, long *p, StateMachine *m);
 long validate_utf8_fast(const GoString *src); 
 
diff --git a/native/scanning.c b/native/scanning.c
index ae485d4fc..9ae718bc7 100644
--- a/native/scanning.c
+++ b/native/scanning.c
@@ -1445,9 +1445,9 @@ long skip_one(const GoString *src, long *p, StateMachine *m, uint64_t flags) {
     return fsm_exec(m, src, p, flags);
 }
 
-long validate_one(const GoString *src, long *p, StateMachine *m) {
+long validate_one(const GoString *src, long *p, StateMachine *m, uint64_t flags) {
     fsm_init(m, FSM_VAL);
-    return fsm_exec(m, src, p, MASK_VALIDATE_STRING);
+    return fsm_exec(m, src, p, flags);
 }
 
 /* Faster skip api for sonic.ast */