diff --git a/src/HttpServer.cc b/src/HttpServer.cc
index 93f8c917..14cb0395 100644
--- a/src/HttpServer.cc
+++ b/src/HttpServer.cc
@@ -1174,7 +1174,7 @@ void prepare_response(Stream *stream, Http2Handler *hd,
 
   auto sessions = hd->get_sessions();
 
-  url = util::percentDecode(std::begin(url), std::end(url));
+  url = util::percent_decode(std::begin(url), std::end(url));
   if (!util::check_path(url)) {
     if (stream->file_ent) {
       sessions->release_fd(stream->file_ent);
diff --git a/src/asio_common.cc b/src/asio_common.cc
index 0319169e..bbcb7e6a 100644
--- a/src/asio_common.cc
+++ b/src/asio_common.cc
@@ -134,7 +134,7 @@ generator_cb file_generator_from_fd(int fd) {
 bool check_path(const std::string &path) { return util::check_path(path); }
 
 std::string percent_decode(const std::string &s) {
-  return util::percentDecode(std::begin(s), std::end(s));
+  return util::percent_decode(std::begin(s), std::end(s));
 }
 
 std::string http_date(int64_t t) { return util::http_date(t); }
diff --git a/src/asio_common.h b/src/asio_common.h
index b2384649..7eacfa51 100644
--- a/src/asio_common.h
+++ b/src/asio_common.h
@@ -55,7 +55,7 @@ void split_path(uri_ref &dst, InputIt first, InputIt last) {
   } else {
     query_first = path_last + 1;
   }
-  dst.path = util::percentDecode(first, path_last);
+  dst.path = util::percent_decode(first, path_last);
   dst.raw_path.assign(first, path_last);
   dst.raw_query.assign(query_first, last);
 }
diff --git a/src/http2.h b/src/http2.h
index dedee285..7fa42b37 100644
--- a/src/http2.h
+++ b/src/http2.h
@@ -343,7 +343,7 @@ std::string normalize_path(InputIt first, InputIt last) {
         if (util::isHexDigit(*(first + 1)) && util::isHexDigit(*(first + 2))) {
           auto c = (util::hex_to_uint(*(first + 1)) << 4) +
                    util::hex_to_uint(*(first + 2));
-          if (util::inRFC3986UnreservedChars(c)) {
+          if (util::in_rfc3986_unreserved_chars(c)) {
             result += c;
             first += 3;
             continue;
diff --git a/src/nghttp.cc b/src/nghttp.cc
index 057eac01..2a392f67 100644
--- a/src/nghttp.cc
+++ b/src/nghttp.cc
@@ -199,7 +199,7 @@ std::string decode_host(std::string host) {
   auto zone_id_src = (*(zone_start + 1) == '2' && *(zone_start + 2) == '5')
                          ? zone_start + 3
                          : zone_start + 1;
-  auto zone_id = util::percentDecode(zone_id_src, std::end(host));
+  auto zone_id = util::percent_decode(zone_id_src, std::end(host));
   host.erase(zone_start + 1, std::end(host));
   host += zone_id;
   return host;
diff --git a/src/shrpx_config.cc b/src/shrpx_config.cc
index b379b7ac..c6b88721 100644
--- a/src/shrpx_config.cc
+++ b/src/shrpx_config.cc
@@ -1664,7 +1664,7 @@ int parse_config(const char *opt, const char *optarg,
         // Surprisingly, u.field_set & UF_USERINFO is nonzero even if
         // userinfo component is empty string.
         if (!val.empty()) {
-          val = util::percentDecode(val.begin(), val.end());
+          val = util::percent_decode(std::begin(val), std::end(val));
           mod_config()->downstream_http_proxy_userinfo = strcopy(val);
         }
       }
diff --git a/src/util.cc b/src/util.cc
index 5f0a7276..8dd84b1e 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -63,11 +63,9 @@ namespace nghttp2 {
 
 namespace util {
 
-const char DEFAULT_STRIP_CHARSET[] = "\r\n\t ";
-
 const char UPPER_XDIGITS[] = "0123456789ABCDEF";
 
-bool inRFC3986UnreservedChars(const char c) {
+bool in_rfc3986_unreserved_chars(const char c) {
   static constexpr const char unreserved[] = {'-', '.', '_', '~'};
   return isAlpha(c) || isDigit(c) ||
          std::find(std::begin(unreserved), std::end(unreserved), c) !=
@@ -81,12 +79,12 @@ bool in_rfc3986_sub_delims(const char c) {
          std::end(sub_delims);
 }
 
-std::string percentEncode(const unsigned char *target, size_t len) {
+std::string percent_encode(const unsigned char *target, size_t len) {
   std::string dest;
   for (size_t i = 0; i < len; ++i) {
     unsigned char c = target[i];
 
-    if (inRFC3986UnreservedChars(c)) {
+    if (in_rfc3986_unreserved_chars(c)) {
       dest += c;
     } else {
       dest += '%';
@@ -97,15 +95,16 @@ std::string percentEncode(const unsigned char *target, size_t len) {
   return dest;
 }
 
-std::string percentEncode(const std::string &target) {
-  return percentEncode(reinterpret_cast<const unsigned char *>(target.c_str()),
-                       target.size());
+std::string percent_encode(const std::string &target) {
+  return percent_encode(reinterpret_cast<const unsigned char *>(target.c_str()),
+                        target.size());
 }
 
 std::string percent_encode_path(const std::string &s) {
   std::string dest;
   for (auto c : s) {
-    if (inRFC3986UnreservedChars(c) || in_rfc3986_sub_delims(c) || c == '/') {
+    if (in_rfc3986_unreserved_chars(c) || in_rfc3986_sub_delims(c) ||
+        c == '/') {
       dest += c;
       continue;
     }
diff --git a/src/util.h b/src/util.h
index 8eb88cdd..b2e62171 100644
--- a/src/util.h
+++ b/src/util.h
@@ -64,104 +64,6 @@ constexpr const char NGHTTP2_H1_1[] = "http/1.1";
 
 namespace util {
 
-extern const char DEFAULT_STRIP_CHARSET[];
-
-template <typename InputIterator>
-std::pair<InputIterator, InputIterator>
-stripIter(InputIterator first, InputIterator last,
-          const char *chars = DEFAULT_STRIP_CHARSET) {
-  for (; first != last && strchr(chars, *first) != 0; ++first)
-    ;
-  if (first == last) {
-    return std::make_pair(first, last);
-  }
-  InputIterator left = last - 1;
-  for (; left != first && strchr(chars, *left) != 0; --left)
-    ;
-  return std::make_pair(first, left + 1);
-}
-
-template <typename InputIterator, typename OutputIterator>
-OutputIterator splitIter(InputIterator first, InputIterator last,
-                         OutputIterator out, char delim, bool doStrip = false,
-                         bool allowEmpty = false) {
-  for (InputIterator i = first; i != last;) {
-    InputIterator j = std::find(i, last, delim);
-    std::pair<InputIterator, InputIterator> p(i, j);
-    if (doStrip) {
-      p = stripIter(i, j);
-    }
-    if (allowEmpty || p.first != p.second) {
-      *out++ = p;
-    }
-    i = j;
-    if (j != last) {
-      ++i;
-    }
-  }
-  if (allowEmpty && (first == last || *(last - 1) == delim)) {
-    *out++ = std::make_pair(last, last);
-  }
-  return out;
-}
-
-template <typename InputIterator, typename OutputIterator>
-OutputIterator split(InputIterator first, InputIterator last,
-                     OutputIterator out, char delim, bool doStrip = false,
-                     bool allowEmpty = false) {
-  for (InputIterator i = first; i != last;) {
-    InputIterator j = std::find(i, last, delim);
-    std::pair<InputIterator, InputIterator> p(i, j);
-    if (doStrip) {
-      p = stripIter(i, j);
-    }
-    if (allowEmpty || p.first != p.second) {
-      *out++ = std::string(p.first, p.second);
-    }
-    i = j;
-    if (j != last) {
-      ++i;
-    }
-  }
-  if (allowEmpty && (first == last || *(last - 1) == delim)) {
-    *out++ = std::string(last, last);
-  }
-  return out;
-}
-
-template <typename InputIterator, typename DelimiterType>
-std::string strjoin(InputIterator first, InputIterator last,
-                    const DelimiterType &delim) {
-  std::string result;
-  if (first == last) {
-    return result;
-  }
-  InputIterator beforeLast = last - 1;
-  for (; first != beforeLast; ++first) {
-    result += *first;
-    result += delim;
-  }
-  result += *beforeLast;
-  return result;
-}
-
-template <typename InputIterator>
-std::string joinPath(InputIterator first, InputIterator last) {
-  std::vector<std::string> elements;
-  for (; first != last; ++first) {
-    if (*first == "..") {
-      if (!elements.empty()) {
-        elements.pop_back();
-      }
-    } else if (*first == ".") {
-      // do nothing
-    } else {
-      elements.push_back(*first);
-    }
-  }
-  return strjoin(elements.begin(), elements.end(), "/");
-}
-
 inline bool isAlpha(const char c) {
   return ('A' <= c && c <= 'Z') || ('a' <= c && c <= 'z');
 }
@@ -172,7 +74,7 @@ inline bool isHexDigit(const char c) {
   return isDigit(c) || ('A' <= c && c <= 'F') || ('a' <= c && c <= 'f');
 }
 
-bool inRFC3986UnreservedChars(const char c);
+bool in_rfc3986_unreserved_chars(const char c);
 
 bool in_rfc3986_sub_delims(const char c);
 
@@ -185,15 +87,15 @@ bool in_attr_char(char c);
 // if isHexDigit(c) is false.
 uint32_t hex_to_uint(char c);
 
-std::string percentEncode(const unsigned char *target, size_t len);
+std::string percent_encode(const unsigned char *target, size_t len);
 
-std::string percentEncode(const std::string &target);
+std::string percent_encode(const std::string &target);
 
 // percent-encode path component of URI |s|.
 std::string percent_encode_path(const std::string &s);
 
 template <typename InputIt>
-std::string percentDecode(InputIt first, InputIt last) {
+std::string percent_decode(InputIt first, InputIt last) {
   std::string result;
   for (; first != last; ++first) {
     if (*first == '%') {
diff --git a/src/util_test.cc b/src/util_test.cc
index da2485a9..77542017 100644
--- a/src/util_test.cc
+++ b/src/util_test.cc
@@ -147,15 +147,15 @@ void test_util_percent_encode_path(void) {
 void test_util_percent_decode(void) {
   {
     std::string s = "%66%6F%6f%62%61%72";
-    CU_ASSERT("foobar" == util::percentDecode(std::begin(s), std::end(s)));
+    CU_ASSERT("foobar" == util::percent_decode(std::begin(s), std::end(s)));
   }
   {
     std::string s = "%66%6";
-    CU_ASSERT("f%6" == util::percentDecode(std::begin(s), std::end(s)));
+    CU_ASSERT("f%6" == util::percent_decode(std::begin(s), std::end(s)));
   }
   {
     std::string s = "%66%";
-    CU_ASSERT("f%" == util::percentDecode(std::begin(s), std::end(s)));
+    CU_ASSERT("f%" == util::percent_decode(std::begin(s), std::end(s)));
   }
 }