diff --git a/libutils/Unicode.cpp b/libutils/Unicode.cpp
index b6e457b..843a81a 100644
--- a/libutils/Unicode.cpp
+++ b/libutils/Unicode.cpp
@@ -359,49 +359,6 @@
 // UTF-8
 // --------------------------------------------------------------------------
 
-ssize_t utf8_length(const char *src)
-{
-    const char *cur = src;
-    size_t ret = 0;
-    while (*cur != '\0') {
-        const char first_char = *cur++;
-        if ((first_char & 0x80) == 0) { // ASCII
-            ret += 1;
-            continue;
-        }
-        // (UTF-8's character must not be like 10xxxxxx,
-        //  but 110xxxxx, 1110xxxx, ... or 1111110x)
-        if ((first_char & 0x40) == 0) {
-            return -1;
-        }
-
-        int32_t mask, to_ignore_mask;
-        size_t num_to_read = 0;
-        char32_t utf32 = 0;
-        for (num_to_read = 1, mask = 0x40, to_ignore_mask = 0x80;
-             num_to_read < 5 && (first_char & mask);
-             num_to_read++, to_ignore_mask |= mask, mask >>= 1) {
-            if ((*cur & 0xC0) != 0x80) { // must be 10xxxxxx
-                return -1;
-            }
-            // 0x3F == 00111111
-            utf32 = (utf32 << 6) + (*cur++ & 0x3F);
-        }
-        // "first_char" must be (110xxxxx - 11110xxx)
-        if (num_to_read == 5) {
-            return -1;
-        }
-        to_ignore_mask |= mask;
-        utf32 |= ((~to_ignore_mask) & first_char) << (6 * (num_to_read - 1));
-        if (utf32 > kUnicodeMaxCodepoint) {
-            return -1;
-        }
-
-        ret += num_to_read;
-    }
-    return ret;
-}
-
 ssize_t utf16_to_utf8_length(const char16_t *src, size_t src_len)
 {
     if (src == nullptr || src_len == 0) {
diff --git a/libutils/include/utils/Unicode.h b/libutils/include/utils/Unicode.h
index fc6712d..0087383 100644
--- a/libutils/include/utils/Unicode.h
+++ b/libutils/include/utils/Unicode.h
@@ -111,24 +111,6 @@
 void utf16_to_utf8(const char16_t* src, size_t src_len, char* dst, size_t dst_len);
 
 /**
- * Returns the length of "src" when "src" is valid UTF-8 string.
- * Returns 0 if src is NULL or 0-length string. Returns -1 when the source
- * is an invalid string.
- *
- * This function should be used to determine whether "src" is valid UTF-8
- * characters with valid unicode codepoints. "src" must be nul-terminated.
- *
- * If you are going to use other utf8_to_... functions defined in this header
- * with string which may not be valid UTF-8 with valid codepoint (form 0 to
- * 0x10FFFF), you should use this function before calling others, since the
- * other functions do not check whether the string is valid UTF-8 or not.
- *
- * If you do not care whether "src" is valid UTF-8 or not, you should use
- * strlen() as usual, which should be much faster.
- */
-ssize_t utf8_length(const char *src);
-
-/**
  * Returns the UTF-16 length of UTF-8 string "src". Returns -1 in case
  * it's invalid utf8. No buffer over-read occurs because of bound checks. Using overreadIsFatal you
  * can ask to log a message and fail in case the invalid utf8 could have caused an override if no