diff --git a/buffet/url_utils.cc b/buffet/url_utils.cc
new file mode 100644
index 0000000..08d78f7
--- /dev/null
+++ b/buffet/url_utils.cc
@@ -0,0 +1,162 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "buffet/url_utils.h"
+
+#include <algorithm>
+
+namespace {
+// Given a URL string, determine where the query string starts and ends.
+// URLs have schema, domain and path (along with possible user name, password
+// and port number which are of no interest for us here) which could optionally
+// have a query string that is separated from the path by '?'. Finally, the URL
+// could also have a '#'-separated URL fragment which is usually used by the
+// browser as a bookmark element. So, for example:
+//    http://server.com/path/to/object?k=v&foo=bar#fragment
+// Here:
+//    http://server.com/path/to/object - is the URL of the object,
+//    ?k=v&foo=bar                     - URL query string
+//    #fragment                        - URL framgment string
+// If |exclude_fragment| is true, the function returns the start character and
+// the length of the query string alone. If it is false, the query string length
+// will include both the query string and the fragment.
+bool GetQueryStringPos(const std::string& url, bool exclude_fragment,
+                       size_t* query_pos, size_t* query_len) {
+  size_t query_start = url.find_first_of("?#");
+  if (query_start == std::string::npos) {
+    *query_pos = url.size();
+    if (query_len)
+      *query_len = 0;
+    return false;
+  }
+
+  *query_pos = query_start;
+  if (query_len) {
+    size_t query_end = url.size();
+
+    if (exclude_fragment) {
+      if (url[query_start] == '?') {
+        size_t pos_fragment = url.find('#', query_start);
+        if (pos_fragment != std::string::npos)
+          query_end = pos_fragment;
+      } else {
+        query_end = query_start;
+      }
+    }
+    *query_len = query_end - query_start;
+  }
+  return true;
+}
+}  // anonymous namespace
+
+std::string chromeos::url::TrimOffQueryString(std::string* url) {
+  size_t query_pos;
+  if (!GetQueryStringPos(*url, false, &query_pos, nullptr))
+    return std::string();
+  std::string query_string = url->substr(query_pos);
+  url->resize(query_pos);
+  return query_string;
+}
+
+std::string chromeos::url::Combine(
+    const std::string& url, const std::string& subpath) {
+  return CombineMultiple(url, {subpath});
+}
+
+std::string chromeos::url::CombineMultiple(
+    const std::string& url, const std::vector<std::string>& parts) {
+  std::string result = url;
+  if (!parts.empty()) {
+    std::string query_string = TrimOffQueryString(&result);
+    for (auto&& part : parts) {
+      if (!part.empty()) {
+        if (!result.empty() && result.back() != '/')
+          result += '/';
+        size_t non_slash_pos = part.find_first_not_of('/');
+        if (non_slash_pos != std::string::npos)
+          result += part.substr(non_slash_pos);
+      }
+    }
+    result += query_string;
+  }
+  return result;
+}
+
+std::string chromeos::url::GetQueryString(
+    const std::string& url, bool remove_fragment) {
+  std::string query_string;
+  size_t query_pos, query_len;
+  if (GetQueryStringPos(url, remove_fragment, &query_pos, &query_len)) {
+    query_string = url.substr(query_pos, query_len);
+  }
+  return query_string;
+}
+
+chromeos::data_encoding::WebParamList chromeos::url::GetQueryStringParameters(
+    const std::string& url) {
+  // Extract the query string and remove the leading '?'.
+  std::string query_string = GetQueryString(url, true).substr(1);
+  return chromeos::data_encoding::WebParamsDecode(query_string);
+}
+
+std::string chromeos::url::GetQueryStringValue(
+    const std::string& url, const std::string& name) {
+  return GetQueryStringValue(GetQueryStringParameters(url), name);
+}
+
+std::string chromeos::url::GetQueryStringValue(
+    const chromeos::data_encoding::WebParamList& params,
+    const std::string& name) {
+  for (auto&& pair : params) {
+    if (name.compare(pair.first) == 0)
+      return pair.second;
+  }
+  return std::string();
+}
+
+std::string chromeos::url::RemoveQueryString(
+    const std::string& url, bool remove_fragment_too) {
+  size_t query_pos, query_len;
+  if (!GetQueryStringPos(url, !remove_fragment_too, &query_pos, &query_len))
+    return url;
+  std::string result = url.substr(0, query_pos);
+  size_t fragment_pos = query_pos + query_len;
+  if (fragment_pos < url.size()) {
+    result += url.substr(fragment_pos);
+  }
+  return result;
+}
+
+std::string chromeos::url::AppendQueryParam(
+    const std::string& url, const std::string& name, const std::string& value) {
+  return AppendQueryParams(url, {{name, value}});
+}
+
+std::string chromeos::url::AppendQueryParams(
+    const std::string& url,
+    const chromeos::data_encoding::WebParamList& params) {
+  if (params.empty())
+    return url;
+  size_t query_pos, query_len;
+  GetQueryStringPos(url, true, &query_pos, &query_len);
+  size_t fragment_pos = query_pos + query_len;
+  std::string result = url.substr(0, fragment_pos);
+  if (query_len == 0) {
+    result += '?';
+  } else if (query_len > 1) {
+    result += '&';
+  }
+  result += chromeos::data_encoding::WebParamsEncode(params);
+  if (fragment_pos < url.size()) {
+    result += url.substr(fragment_pos);
+  }
+  return result;
+}
+
+bool chromeos::url::HasQueryString(const std::string& url) {
+  size_t query_pos, query_len;
+  GetQueryStringPos(url, true, &query_pos, &query_len);
+  return (query_len > 0);
+}
+