diff --git a/Include/Fledasty/Strings/UTF8String.h b/Include/Fledasty/Strings/UTF8String.h
index 09cb06f..31104ff 100644
--- a/Include/Fledasty/Strings/UTF8String.h
+++ b/Include/Fledasty/Strings/UTF8String.h
@@ -42,6 +42,8 @@ FledastyError fledasty_utf8_string_insert_before_string(FledastyUtf8String *curr
 FledastyError fledasty_utf8_string_insert_after_string(FledastyUtf8String *current_string, unsigned char *after_character_string, size_t after_character_string_length, unsigned char *character_string, size_t character_string_length);
 FledastyError fledasty_utf8_string_insert_at_index(FledastyUtf8String *current_string, size_t index, unsigned char *character_string, size_t character_string_length);
 
+FledastyError fledasty_utf8_string_replace_string(FledastyUtf8String *current_string, unsigned char *replace_character_string, size_t replace_character_string_length, unsigned char *character_string, size_t character_string_length);
+
 bool fledasty_utf8_string_has_string(const FledastyUtf8String *current_string, unsigned char *character_string, size_t character_string_length);
 static inline bool fledasty_utf8_string_is_empty(const FledastyUtf8String *current_string) { return current_string == NULL || current_string->size == 0; }
 
diff --git a/Src/Strings/UTF8String.c b/Src/Strings/UTF8String.c
index 28a5be6..1ee07f5 100644
--- a/Src/Strings/UTF8String.c
+++ b/Src/Strings/UTF8String.c
@@ -29,7 +29,6 @@
 #include <Hallocy/Core/Allocator.h>
 #include <Hallocy/Core/Memory.h>
 #include <Hallocy/Utils/Error.h>
-#include <stdint.h>
 
 FledastyError fledasty_utf8_string_initialize(FledastyUtf8String *new_string, unsigned char *character_string, size_t character_string_length) {
     if (new_string == NULL) {
@@ -181,6 +180,31 @@ FledastyError fledasty_utf8_string_insert_at_index(FledastyUtf8String *current_s
     return FLEDASTY_ERROR_NONE;
 }
 
+FledastyError fledasty_utf8_string_replace_string(FledastyUtf8String *current_string, unsigned char *replace_character_string, size_t replace_character_string_length, unsigned char *character_string, size_t character_string_length) {
+    if (current_string == NULL || replace_character_string == NULL || replace_character_string_length == 0 || character_string == NULL || character_string_length == 0) {
+        return FLEDASTY_ERROR_INVALID_POINTER;
+    }
+
+    if (!fledasty_utf8_string_validate(replace_character_string, replace_character_string_length) || !fledasty_utf8_string_validate(character_string, character_string_length)) {
+        return FLEDASTY_ERROR_INVALID_VALUE;
+    }
+
+    size_t index = 0;
+    while (index < current_string->size - replace_character_string_length && !hallocy_compare_memory(current_string->character_string + index, replace_character_string, replace_character_string_length)) {
+        index += 1;
+    }
+
+    if (index == current_string->size - replace_character_string_length) {
+        return FLEDASTY_ERROR_VALUE_NOT_FOUND;
+    }
+
+    hallocy_move_memory(current_string->character_string + index + character_string_length, current_string->character_string + index + replace_character_string_length, current_string->size - (index + replace_character_string_length));
+    hallocy_copy_memory(current_string->character_string + index, character_string, character_string_length);
+
+    current_string->size += character_string_length - replace_character_string_length;
+    return FLEDASTY_ERROR_NONE;
+}
+
 bool fledasty_utf8_string_has_string(const FledastyUtf8String *current_string, unsigned char *character_string, size_t character_string_length) {
     if (current_string == NULL || character_string == NULL || character_string_length == 0) {
         return false;
diff --git a/Tests/Main.c b/Tests/Main.c
index 598fe88..bd7cc1e 100644
--- a/Tests/Main.c
+++ b/Tests/Main.c
@@ -237,6 +237,8 @@ int main() {
     printf("Insert After: %s\n", test_utf8_string.character_string);
     fledasty_utf8_string_insert_at_index(&test_utf8_string, test_utf8_string.size - 1, (unsigned char*)"index", 5);
     printf("Insert at Index: %s\n", test_utf8_string.character_string);
+    fledasty_utf8_string_replace_string(&test_utf8_string, (unsigned char*)"😀", 4, (unsigned char*)"𓃶 ", 5);
+    printf("Replace: %s\n", test_utf8_string.character_string);
 
     if (fledasty_utf8_string_has_string(&test_utf8_string, (unsigned char*)"😀", 4)) {
         printf("String contains 😀!\n");