diff --git a/client/snapClient.cpp b/client/snapClient.cpp
index eba291bf..a567bfa0 100644
--- a/client/snapClient.cpp
+++ b/client/snapClient.cpp
@@ -171,7 +171,7 @@ int main (int argc, char **argv)
 				if (userValue.getValue().empty())
 					std::invalid_argument("user must not be empty");
 
-				vector<string> user_group = split(userValue.getValue(), ':');
+				vector<string> user_group = utils::string::split(userValue.getValue(), ':');
 				user = user_group[0];
 				if (user_group.size() > 1)
 					group = user_group[1];
diff --git a/common/sampleFormat.cpp b/common/sampleFormat.cpp
index 699cdc41..e03e245c 100644
--- a/common/sampleFormat.cpp
+++ b/common/sampleFormat.cpp
@@ -22,6 +22,7 @@
 
 #include "sampleFormat.h"
 #include "common/strCompat.h"
+#include "common/utils/string_utils.h"
 #include "common/utils.h"
 #include "common/log.h"
 
@@ -57,7 +58,7 @@ string SampleFormat::getFormat() const
 void SampleFormat::setFormat(const std::string& format)
 {
 	std::vector<std::string> strs;
-	strs = split(format, ':');
+	strs = utils::string::split(format, ':');
 	if (strs.size() == 3)
 		setFormat(
 		    cpt::stoul(strs[0]),
diff --git a/common/utils.h b/common/utils.h
index 7d060e46..83b25984 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -20,8 +20,8 @@
 #define UTILS_H
 
 #include "common/strCompat.h"
+#include "common/utils/string_utils.h"
 
-#include <algorithm>
 #include <functional>
 #include <cctype>
 #include <locale>
@@ -51,94 +51,11 @@
 #endif
 
 
-// trim from start
-static inline std::string &ltrim(std::string &s)
-{
-	s.erase(s.begin(), std::find_if(s.begin(), s.end(), std::not1(std::ptr_fun<int, int>(std::isspace))));
-	return s;
-}
-
-// trim from end
-static inline std::string &rtrim(std::string &s)
-{
-	s.erase(std::find_if(s.rbegin(), s.rend(), std::not1(std::ptr_fun<int, int>(std::isspace))).base(), s.end());
-	return s;
-}
-
-// trim from both ends
-static inline std::string &trim(std::string &s)
-{
-	return ltrim(rtrim(s));
-}
-
-// trim from start
-static inline std::string ltrim_copy(const std::string &s)
-{
-	std::string str(s);
-	return ltrim(str);
-}
-
-// trim from end
-static inline std::string rtrim_copy(const std::string &s)
-{
-	std::string str(s);
-	return rtrim(str);
-}
-
-// trim from both ends
-static inline std::string trim_copy(const std::string &s)
-{
-	std::string str(s);
-	return trim(str);
-}
-
-// decode %xx to char
-static std::string uriDecode(const std::string& src) {
-	std::string ret;
-	char ch;
-	for (size_t i=0; i<src.length(); i++)
-	{
-		if (int(src[i]) == 37)
-		{
-			unsigned int ii;
-			sscanf(src.substr(i+1, 2).c_str(), "%x", &ii);
-			ch = static_cast<char>(ii);
-			ret += ch;
-			i += 2;
-		}
-		else
-		{
-			ret += src[i];
-		}
-	}
-	return (ret);
-}
-
-
-
-static std::vector<std::string> &split(const std::string &s, char delim, std::vector<std::string> &elems)
-{
-	std::stringstream ss(s);
-	std::string item;
-	while (std::getline(ss, item, delim))
-	{
-		elems.push_back(item);
-	}
-	return elems;
-}
-
-
-static std::vector<std::string> split(const std::string &s, char delim)
-{
-	std::vector<std::string> elems;
-	split(s, delim, elems);
-	return elems;
-}
-
+namespace strutils = utils::string;
 
 static int mkdirRecursive(const char *path, mode_t mode)
 {
-	std::vector<std::string> pathes = split(path, '/');
+	std::vector<std::string> pathes = strutils::split(path, '/');
 	std::stringstream ss;
 	int res = 0;
 	for (const auto& p: pathes)
@@ -166,7 +83,7 @@ static std::string execGetOutput(const std::string& cmd)
 		if (fgets(buffer, 1024, pipe.get()) != NULL)
 			result += buffer;
 	}
-	return trim(result);
+	return strutils::trim(result);
 }
 
 
@@ -182,18 +99,18 @@ static std::string getOS()
 {
 	std::string os;
 #ifdef ANDROID
-	os = trim_copy("Android " + getProp("ro.build.version.release"));
+	os = strutils::trim_copy("Android " + getProp("ro.build.version.release"));
 #else
 	os = execGetOutput("lsb_release -d");
 	if ((os.find(":") != std::string::npos) && (os.find("lsb_release") == std::string::npos))
-		os = trim_copy(os.substr(os.find(":") + 1));
+		os = strutils::trim_copy(os.substr(os.find(":") + 1));
 #endif
 	if (os.empty())
 	{
-		os = trim_copy(execGetOutput("grep /etc/os-release /etc/openwrt_release -e PRETTY_NAME -e DISTRIB_DESCRIPTION"));
+		os = strutils::trim_copy(execGetOutput("grep /etc/os-release /etc/openwrt_release -e PRETTY_NAME -e DISTRIB_DESCRIPTION"));
 		if (os.find("=") != std::string::npos)
 		{
-			os = trim_copy(os.substr(os.find("=") + 1));
+			os = strutils::trim_copy(os.substr(os.find("=") + 1));
 			os.erase(std::remove(os.begin(), os.end(), '"'), os.end());
 			os.erase(std::remove(os.begin(), os.end(), '\''), os.end());
 		}
@@ -204,7 +121,7 @@ static std::string getOS()
 		uname(&u);
 		os = u.sysname;
 	}
-	return trim_copy(os);
+	return strutils::trim_copy(os);
 }
 
 
@@ -235,7 +152,7 @@ static std::string getArch()
 		arch = execGetOutput("uname -i");
 	if (arch.empty() || (arch == "unknown"))
 		arch = execGetOutput("uname -m");
-	return trim_copy(arch);
+	return strutils::trim_copy(arch);
 }
 
 
@@ -249,7 +166,7 @@ static long uptime()
 	std::string uptime = execGetOutput("sysctl kern.boottime");
 	if ((uptime.find(" sec = ") != std::string::npos) && (uptime.find(",") != std::string::npos))
 	{
-		uptime = trim_copy(uptime.substr(uptime.find(" sec = ") + 7));
+		uptime = strutils::trim_copy(uptime.substr(uptime.find(" sec = ") + 7));
 		uptime.resize(uptime.find(","));
 		timeval now;
 		gettimeofday(&now, NULL);
@@ -361,7 +278,7 @@ static std::string getMacAddress(int sock)
 					std::string line;
 					if (infile.good() && std::getline(infile, line))
 					{
-						trim(line);
+						strutils::trim(line);
 						if ((line.size() == 17) && (line[2] == ':'))
 							return line;
 					}
@@ -391,6 +308,22 @@ static std::string getMacAddress(int sock)
 }
 
 
+static std::string getClientId(const std::string defaultId = "")
+{
+	std::string result = defaultId;
+	if (!result.empty())
+		return result;
+
+#ifdef ANDROID
+	result = getProp("ro.serialno");
+	if (!result.empty())
+		return result;
+#endif
+
+	return getHostName();
+}
+
+
 #endif
 
 
diff --git a/common/utils/string_utils.h b/common/utils/string_utils.h
new file mode 100644
index 00000000..6e86b4a9
--- /dev/null
+++ b/common/utils/string_utils.h
@@ -0,0 +1,103 @@
+#ifndef STRING_UTILS_H
+#define STRING_UTILS_H
+
+#include <algorithm>
+#include <string>
+#include <sstream>
+#include <vector>
+
+
+namespace utils
+{
+namespace string
+{
+
+// trim from start
+static inline std::string &ltrim(std::string &s)
+{
+	s.erase(s.begin(), std::find_if(s.begin(), s.end(), std::not1(std::ptr_fun<int, int>(std::isspace))));
+	return s;
+}
+
+// trim from end
+static inline std::string &rtrim(std::string &s)
+{
+	s.erase(std::find_if(s.rbegin(), s.rend(), std::not1(std::ptr_fun<int, int>(std::isspace))).base(), s.end());
+	return s;
+}
+
+// trim from both ends
+static inline std::string &trim(std::string &s)
+{
+	return ltrim(rtrim(s));
+}
+
+// trim from start
+static inline std::string ltrim_copy(const std::string &s)
+{
+	std::string str(s);
+	return ltrim(str);
+}
+
+// trim from end
+static inline std::string rtrim_copy(const std::string &s)
+{
+	std::string str(s);
+	return rtrim(str);
+}
+
+// trim from both ends
+static inline std::string trim_copy(const std::string &s)
+{
+	std::string str(s);
+	return trim(str);
+}
+
+// decode %xx to char
+static std::string uriDecode(const std::string& src) {
+	std::string ret;
+	char ch;
+	for (size_t i=0; i<src.length(); i++)
+	{
+		if (int(src[i]) == 37)
+		{
+			unsigned int ii;
+			sscanf(src.substr(i+1, 2).c_str(), "%x", &ii);
+			ch = static_cast<char>(ii);
+			ret += ch;
+			i += 2;
+		}
+		else
+		{
+			ret += src[i];
+		}
+	}
+	return (ret);
+}
+
+
+
+static std::vector<std::string> &split(const std::string &s, char delim, std::vector<std::string> &elems)
+{
+	std::stringstream ss(s);
+	std::string item;
+	while (std::getline(ss, item, delim))
+	{
+		elems.push_back(item);
+	}
+	return elems;
+}
+
+
+static std::vector<std::string> split(const std::string &s, char delim)
+{
+	std::vector<std::string> elems;
+	split(s, delim, elems);
+	return elems;
+}
+
+} // namespace string
+} // namespace utils
+
+#endif
+
diff --git a/server/config.h b/server/config.h
index 12c3effa..22c5e4fa 100644
--- a/server/config.h
+++ b/server/config.h
@@ -24,9 +24,11 @@
 #include <vector>
 #include <sys/time.h>
 #include "externals/json.hpp"
+#include "common/utils/string_utils.h"
 #include "common/utils.h"
 
 
+namespace strutils = utils::string;
 using json = nlohmann::json;
 
 struct ClientInfo;
@@ -93,11 +95,11 @@ struct Host
 
 	void fromJson(const json& j)
 	{
-		name = trim_copy(jGet<std::string>(j, "name", ""));
-		mac = trim_copy(jGet<std::string>(j, "mac", ""));
-		os = trim_copy(jGet<std::string>(j, "os", ""));
-		arch = trim_copy(jGet<std::string>(j, "arch", ""));
-		ip = trim_copy(jGet<std::string>(j, "ip", ""));
+		name = strutils::trim_copy(jGet<std::string>(j, "name", ""));
+		mac = strutils::trim_copy(jGet<std::string>(j, "mac", ""));
+		os = strutils::trim_copy(jGet<std::string>(j, "os", ""));
+		arch = strutils::trim_copy(jGet<std::string>(j, "arch", ""));
+		ip = strutils::trim_copy(jGet<std::string>(j, "ip", ""));
 	}
 
 	json toJson()
@@ -127,7 +129,7 @@ struct ClientConfig
 
 	void fromJson(const json& j)
 	{
-		name = trim_copy(jGet<std::string>(j, "name", ""));
+		name = strutils::trim_copy(jGet<std::string>(j, "name", ""));
 		volume.fromJson(j["volume"]);
 		latency = jGet<int32_t>(j, "latency", 0);
 		instance = jGet<size_t>(j, "instance", 1);
@@ -136,7 +138,7 @@ struct ClientConfig
 	json toJson()
 	{
 		json j;
-		j["name"] = trim_copy(name);
+		j["name"] = strutils::trim_copy(name);
 		j["volume"] = volume.toJson();
 		j["latency"] = latency;
 		j["instance"] = instance;
@@ -163,16 +165,16 @@ struct Snapcast
 
 	virtual void fromJson(const json& j)
 	{
-		name = trim_copy(jGet<std::string>(j, "name", ""));
-		version = trim_copy(jGet<std::string>(j, "version", ""));
+		name = strutils::trim_copy(jGet<std::string>(j, "name", ""));
+		version = strutils::trim_copy(jGet<std::string>(j, "version", ""));
 		protocolVersion = jGet<int>(j, "protocolVersion", 1);
 	}
 
 	virtual json toJson()
 	{
 		json j;
-		j["name"] = trim_copy(name);
-		j["version"] = trim_copy(version);
+		j["name"] = strutils::trim_copy(name);
+		j["version"] = strutils::trim_copy(version);
 		j["protocolVersion"] = protocolVersion;
 		return j;
 	}
@@ -266,9 +268,9 @@ struct Group
 
 	void fromJson(const json& j)
 	{
-		name = trim_copy(jGet<std::string>(j, "name", ""));
-		id = trim_copy(jGet<std::string>(j, "id", ""));
-		streamId = trim_copy(jGet<std::string>(j, "stream_id", ""));
+		name = strutils::trim_copy(jGet<std::string>(j, "name", ""));
+		id = strutils::trim_copy(jGet<std::string>(j, "id", ""));
+		streamId = strutils::trim_copy(jGet<std::string>(j, "stream_id", ""));
 		muted = jGet<bool>(j, "muted", false);
 		clients.clear();
 		if (j.count("clients"))
@@ -286,9 +288,9 @@ struct Group
 	json toJson()
 	{
 		json j;
-		j["name"] = trim_copy(name);
-		j["id"] = trim_copy(id);
-		j["stream_id"] = trim_copy(streamId);
+		j["name"] = strutils::trim_copy(name);
+		j["id"] = strutils::trim_copy(id);
+		j["stream_id"] = strutils::trim_copy(streamId);
 		j["muted"] = muted;
 
 		json jClients = json::array();
diff --git a/server/encoder/encoderFactory.cpp b/server/encoder/encoderFactory.cpp
index 292f2d56..75e99add 100644
--- a/server/encoder/encoderFactory.cpp
+++ b/server/encoder/encoderFactory.cpp
@@ -20,7 +20,7 @@
 #include "pcmEncoder.h"
 #include "oggEncoder.h"
 #include "flacEncoder.h"
-#include "common/utils.h"
+#include "common/utils/string_utils.h"
 #include "common/snapException.h"
 #include "common/log.h"
 
@@ -35,8 +35,8 @@ Encoder* EncoderFactory::createEncoder(const std::string& codecSettings) const
 	std::string codecOptions;
 	if (codec.find(":") != std::string::npos)
 	{
-		codecOptions = trim_copy(codec.substr(codec.find(":") + 1));
-		codec = trim_copy(codec.substr(0, codec.find(":")));
+		codecOptions = utils::string::trim_copy(codec.substr(codec.find(":") + 1));
+		codec = utils::string::trim_copy(codec.substr(0, codec.find(":")));
 	}
 	if (codec == "ogg")
 		encoder = new OggEncoder(codecOptions);
diff --git a/server/encoder/oggEncoder.cpp b/server/encoder/oggEncoder.cpp
index 1f857bb8..3aef4e89 100644
--- a/server/encoder/oggEncoder.cpp
+++ b/server/encoder/oggEncoder.cpp
@@ -22,6 +22,7 @@
 #include "oggEncoder.h"
 #include "common/snapException.h"
 #include "common/strCompat.h"
+#include "common/utils/string_utils.h"
 #include "common/utils.h"
 #include "common/log.h"
 
@@ -144,11 +145,11 @@ void OggEncoder::initEncoder()
 {
 	if (codecOptions_.find(":") == string::npos)
 		throw SnapException("Invalid codec options: \"" + codecOptions_ + "\"");
-	string mode = trim_copy(codecOptions_.substr(0, codecOptions_.find(":")));
+	string mode = utils::string::trim_copy(codecOptions_.substr(0, codecOptions_.find(":")));
 	if (mode != "VBR")
 		throw SnapException("Unsupported codec mode: \"" + mode + "\". Available: \"VBR\"");
 
-	string qual = trim_copy(codecOptions_.substr(codecOptions_.find(":") + 1));
+	string qual = utils::string::trim_copy(codecOptions_.substr(codecOptions_.find(":") + 1));
 	double quality = 1.0;
 	try
 	{
diff --git a/server/snapServer.cpp b/server/snapServer.cpp
index 111f0689..050dd60e 100644
--- a/server/snapServer.cpp
+++ b/server/snapServer.cpp
@@ -25,6 +25,7 @@
 #include "common/daemon.h"
 #endif
 #include "common/timeDefs.h"
+#include "common/utils/string_utils.h"
 #include "common/signalHandler.h"
 #include "common/snapException.h"
 #include "common/sampleFormat.h"
@@ -157,7 +158,7 @@ int main(int argc, char* argv[])
 				if (userValue.getValue().empty())
 					std::invalid_argument("user must not be empty");
 
-				vector<string> user_group = split(userValue.getValue(), ':');
+				vector<string> user_group = utils::string::split(userValue.getValue(), ':');
 				user = user_group[0];
 				if (user_group.size() > 1)
 					group = user_group[1];
diff --git a/server/streamreader/airplayStream.cpp b/server/streamreader/airplayStream.cpp
index 7c313038..6ebd3e63 100644
--- a/server/streamreader/airplayStream.cpp
+++ b/server/streamreader/airplayStream.cpp
@@ -18,6 +18,7 @@
 
 #include "airplayStream.h"
 #include "common/snapException.h"
+#include "common/utils/string_utils.h"
 #include "common/utils.h"
 #include "common/log.h"
 
@@ -68,7 +69,7 @@ void AirplayStream::initExeAndPath(const std::string& filename)
 
 void AirplayStream::onStderrMsg(const char* buffer, size_t n)
 {
-	string logmsg = trim_copy(string(buffer, n));
+	string logmsg = utils::string::trim_copy(string(buffer, n));
 	if (logmsg.empty())
 		return;
 	logO << "(" << getName() << ") " << logmsg << "\n";
diff --git a/server/streamreader/processStream.cpp b/server/streamreader/processStream.cpp
index c301c558..21e03726 100644
--- a/server/streamreader/processStream.cpp
+++ b/server/streamreader/processStream.cpp
@@ -22,6 +22,7 @@
 #include <fcntl.h>
 #include "processStream.h"
 #include "common/snapException.h"
+#include "common/utils/string_utils.h"
 #include "common/utils.h"
 #include "common/log.h"
 
@@ -120,7 +121,7 @@ void ProcessStream::onStderrMsg(const char* buffer, size_t n)
 {
 	if (logStderr_)
 	{
-		string line = trim_copy(string(buffer, n));
+		string line = utils::string::trim_copy(string(buffer, n));
 		if ((line.find('\0') == string::npos) && !line.empty())
 			logO << "(" << getName() << ") " << line << "\n";
 	}
diff --git a/server/streamreader/spotifyStream.cpp b/server/streamreader/spotifyStream.cpp
index f621787f..d82974c9 100644
--- a/server/streamreader/spotifyStream.cpp
+++ b/server/streamreader/spotifyStream.cpp
@@ -18,6 +18,7 @@
 
 #include "spotifyStream.h"
 #include "common/snapException.h"
+#include "common/utils/string_utils.h"
 #include "common/utils.h"
 #include "common/log.h"
 
@@ -101,7 +102,7 @@ void SpotifyStream::onStderrMsg(const char* buffer, size_t n)
 	// 2016-11-03 09-00-18 [out] INFO:librespot::session: Connecting to AP lon3-accesspoint-a34.ap.spotify.com:443
 	// 2016-11-03 09-00-18 [out] INFO:librespot::session: Authenticated !
 	watchdog_->trigger();
-	string logmsg = trim_copy(string(buffer, n));
+	string logmsg = utils::string::trim_copy(string(buffer, n));
 	if ((logmsg.find("allocated stream") == string::npos) &&
 		(logmsg.find("Got channel") == string::npos) &&
 		(logmsg.find('\0') == string::npos) &&
diff --git a/server/streamreader/streamUri.cpp b/server/streamreader/streamUri.cpp
index dbdf8e28..eeda6ade 100644
--- a/server/streamreader/streamUri.cpp
+++ b/server/streamreader/streamUri.cpp
@@ -17,12 +17,13 @@
 ***/
 
 #include "streamUri.h"
-#include "common/utils.h"
+#include "common/utils/string_utils.h"
 #include "common/strCompat.h"
 #include "common/log.h"
 
 
 using namespace std;
+namespace strutils = utils::string;
 
 
 StreamUri::StreamUri(const std::string& streamUri)
@@ -32,13 +33,13 @@ StreamUri::StreamUri(const std::string& streamUri)
 // would be more elegant with regex. Not yet supported on my dev machine's gcc 4.8 :(
 	logD << "StreamUri: " << streamUri << "\n";
 	size_t pos;
-	uri = trim_copy(streamUri);
+	uri = strutils::trim_copy(streamUri);
 	while (!uri.empty() && ((uri[0] == '\'') || (uri[0] == '"')))
 		uri = uri.substr(1);
 	while (!uri.empty() && ((uri[uri.length()-1] == '\'') || (uri[uri.length()-1] == '"')))
 		uri = uri.substr(0, this->uri.length()-1);
 
-	string decodedUri = uriDecode(uri);
+	string decodedUri = strutils::uriDecode(uri);
 	logD << "StreamUri: " << decodedUri << "\n";
 
 	string tmp(decodedUri);
@@ -46,7 +47,7 @@ StreamUri::StreamUri(const std::string& streamUri)
 	pos = tmp.find(':');
 	if (pos == string::npos)
 		throw invalid_argument("missing ':'");
-	scheme = trim_copy(tmp.substr(0, pos));
+	scheme = strutils::trim_copy(tmp.substr(0, pos));
 	tmp = tmp.substr(pos + 1);
 	logD << "scheme: '" << scheme << "' tmp: '" << tmp << "'\n";
 
@@ -57,7 +58,7 @@ StreamUri::StreamUri(const std::string& streamUri)
 	pos = tmp.find('/');
 	if (pos == string::npos)
 		throw invalid_argument("missing path separator: '/'");
-	host = trim_copy(tmp.substr(0, pos));
+	host = strutils::trim_copy(tmp.substr(0, pos));
 	tmp = tmp.substr(pos);
 	path = tmp;
 	logD << "host: '" << host << "' tmp: '" << tmp << "' path: '" << path << "'\n";
@@ -66,7 +67,7 @@ StreamUri::StreamUri(const std::string& streamUri)
 	if (pos == string::npos)
 		return;
 
-	path = trim_copy(tmp.substr(0, pos));
+	path = strutils::trim_copy(tmp.substr(0, pos));
 	tmp = tmp.substr(pos + 1);
 	string queryStr = tmp;
 	logD << "path: '" << path << "' tmp: '" << tmp << "' query: '" << queryStr << "'\n";
@@ -76,18 +77,18 @@ StreamUri::StreamUri(const std::string& streamUri)
 	{
 		queryStr = tmp.substr(0, pos);
 		tmp = tmp.substr(pos + 1);
-		fragment = trim_copy(tmp);
+		fragment = strutils::trim_copy(tmp);
 		logD << "query: '" << queryStr << "' fragment: '" << fragment << "' tmp: '" << tmp << "'\n";
 	}
 
-	vector<string> keyValueList = split(queryStr, '&');
+	vector<string> keyValueList = strutils::split(queryStr, '&');
 	for (auto& kv: keyValueList)
 	{
 		pos = kv.find('=');
 		if (pos != string::npos)
 		{
-			string key = trim_copy(kv.substr(0, pos));
-			string value = trim_copy(kv.substr(pos+1));
+			string key = strutils::trim_copy(kv.substr(0, pos));
+			string value = strutils::trim_copy(kv.substr(pos+1));
 			query[key] = value;
 		}
 	}