diff --git a/src/main.c b/src/main.c
index 2299920..2e140e9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3,6 +3,7 @@
 #include "mini_arena.h"
 #include "platform.h"
 #include "pool.h"
+#include "string.h"
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -411,6 +412,38 @@ void apool_test_autogrow(void)
 
 }
 
+void string_test_1(void)
+{
+    TRACEF("\n");
+
+    Str str1 = S_("Hello");
+    printf("str1: %.*s len %d\n", str1.len, str1.str, str1.len);
+    U64 str1_index_of_l = str_find_byte(str1, 'l');
+    U64 str1_index_of_g = str_find_byte(str1, 'g');
+    printf("str1: index of l %ld, index of g: %ld\n", str1_index_of_l, str1_index_of_g);
+
+    MARENA_DEFINE(arena, 512, 1);
+    Allocator alloc = marena_allocator(&arena);
+    Str str2 = str_dup(&alloc, S_(" World"));
+    Str str3 = str_concat(&alloc, str1, str2);
+    printf("str3: %.*s len %d\n", str3.len, str3.str, str3.len);
+}
+
+void string_split_test_1(void)
+{
+    TRACEF("\n");
+
+    Str str1 = S_("a:bb|ccc");
+    Str sep = S_("|:");
+    STRVEC_DEFINE(strings, 16);
+
+    str_split(str1, sep, &strings);
+    for (U32 i = 0; i < strings.len; i++) {
+        Str *str = &strings.strings[i];
+        printf("split %u: '%.*s'\n", i, str->len, str->str);
+    }
+}
+
 int main(int argc, char *argv[])
 {
     arena_test_1();
@@ -423,6 +456,8 @@ int main(int argc, char *argv[])
     apool_test();
     apool_test_autogrow();
     apool_test_miniarena();
+    string_test_1();
+    string_split_test_1();
 
 }
 
diff --git a/src/string.c b/src/string.c
new file mode 100644
index 0000000..1bc3e13
--- /dev/null
+++ b/src/string.c
@@ -0,0 +1,72 @@
+#include "string.h"
+
+Str str_empty(void)
+{
+    static const U8 empty_;
+    static const Str str = {(U8 *)&empty_, 0};
+    return str;
+}
+
+Str str_substr(Str str, U32 start, U32 len)
+{
+    Assert(start < str.len);
+    Assert(len <= str.len);
+
+    Str new_str = str_create(&str.str[start], len);
+    return new_str;
+}
+
+
+Str str_concat(Allocator *alloc, Str first, Str second)
+{
+    Str str;
+
+    str.len = first.len + second.len;
+    str.str = allocator_push(alloc, str.len, 1);;
+
+    MemCopy(str.str, first.str, first.len);
+    MemCopy(&str.str[first.len], second.str, second.len);
+
+    return str;
+}
+
+Str str_push(Allocator *alloc, Str str)
+{
+    U8 *mem = (U8 *)allocator_push(alloc, sizeof(Str) + str.len, alignof(Str));
+    Str *new_str = (Str *)mem;
+    new_str->len = str.len;
+    new_str->str = &mem[sizeof(Str)];
+    if (!str_is_empty(str)) {
+        MemCopy(new_str->str, str.str, str.len);
+    }
+
+    return *new_str;
+}
+
+// split @str on any byte in @separators, place split strings in @vec
+void str_split(Str str, Str separators, StrVec *vec)
+{
+    if (vec->max_len == 0 || str.len == 0) {
+        return;
+    }
+
+    U32 start_pos = 0;
+    for (U32 i = 0; i < str.len; i++) {
+        U8 byte = str.str[i];
+        if (str_find_byte(separators, byte) != -1) {
+            if (vec->len >= vec->max_len) {
+                break;
+            }
+
+            Str sub_str = str_substr(str, start_pos, i - start_pos);
+            vec->strings[vec->len] = sub_str;
+            vec->len++;
+            start_pos = i + 1;
+        }
+    }
+    if (start_pos < str.len && vec->len < vec->max_len) {
+        Str sub_str = str_substr(str, start_pos, str.len - start_pos);
+        vec->strings[vec->len] = sub_str;
+        vec->len++;
+    }
+}
diff --git a/src/string.h b/src/string.h
new file mode 100644
index 0000000..8dd10ba
--- /dev/null
+++ b/src/string.h
@@ -0,0 +1,78 @@
+#pragma once
+#include "base_core.h"
+
+typedef struct Str Str;
+struct Str {
+    U8 *str;
+    U32 len;
+};
+
+Str str_empty(void);
+Str str_substr(Str str, U32 start, U32 len);
+Str str_concat(Allocator *alloc, Str first, Str second);
+Str str_push(Allocator *alloc, Str str);
+
+#define  str_from_lit(str) str_create(((U8 *)str), sizeof(str) -1)
+#define  S_(str) str_from_lit(str)
+#define cstr_len(str) (U32)strlen(str)
+#define str_dup(alloc, str) str_push((alloc), (str))
+
+static INLINE bool str_is_empty(Str str)
+{
+    return str.len == 0;
+}
+
+static INLINE Str str_create(U8 *start, U32 len)
+{
+    Str str = {start, len};
+    return str;
+}
+
+static INLINE Str str_from_cstr(const char *cstr)
+{
+    Str str = str_create((U8 *)cstr, cstr_len(cstr));
+    return str;
+}
+
+static INLINE Str str_push_cstr(Allocator *alloc, const char *cstr)
+{
+    Str str = str_from_cstr(cstr);
+    return str_push(alloc, str);
+}
+
+static INLINE S64 str_find_byte(Str str, U8 byte)
+{
+    for (U32 i = 0; i < str.len; i++) {
+        if (str.str[i] == byte) {
+            return i;
+        }
+    }
+
+    return -1;
+}
+
+static INLINE Str str_skip(Str str, U32 len)
+{
+    U32 skip_len = Min(str.len, len);
+    Str new_str = str_substr(str, skip_len, str.len - skip_len);
+
+    return new_str;
+}
+
+
+// String Vector
+typedef struct StrVec StrVec;
+struct StrVec {
+    Str *strings;
+    U32 len;
+    U32 max_len;
+};
+#define STRVEC_STATIC_INITIALIZER(strings_) STRVEC_INITIALIZER((strings_), ArraySize(strings_))
+#define STRVEC_INITIALIZER(strings_, len_) {.strings = (strings_), .len = 0, .max_len = (len_)}
+#define STRVEC_DEFINE(var_name, len_)  \
+    struct { \
+        Str strings[len_];\
+    } var_name##_strvec_array; \
+    StrVec var_name = STRVEC_STATIC_INITIALIZER(var_name##_strvec_array.strings)
+
+void str_split(Str str, Str separators, StrVec *vec);