diff --git a/cmd/enricher/main.go b/cmd/enricher/main.go
index 28b90db3..23ef5db7 100644
--- a/cmd/enricher/main.go
+++ b/cmd/enricher/main.go
@@ -19,7 +19,8 @@ import (
 
 	// import various formatters
 	"github.com/netsampler/goflow2/format"
-	"github.com/netsampler/goflow2/format/json"
+	"github.com/netsampler/goflow2/format/common"
+	_ "github.com/netsampler/goflow2/format/json"
 	_ "github.com/netsampler/goflow2/format/protobuf"
 
 	// import various transports
@@ -85,8 +86,8 @@ func MapFlow(dbAsn, dbCountry *geoip2.Reader, msg *flowmessage.FlowMessageExt) {
 }
 
 func init() {
-	json.AddJSONField("SrcCountry", json.FORMAT_TYPE_STRING)
-	json.AddJSONField("DstCountry", json.FORMAT_TYPE_STRING)
+	common.AddTextField("SrcCountry", common.FORMAT_TYPE_STRING)
+	common.AddTextField("DstCountry", common.FORMAT_TYPE_STRING)
 }
 
 func main() {
diff --git a/cmd/goflow2/main.go b/cmd/goflow2/main.go
index 0bca1e92..905b3a34 100644
--- a/cmd/goflow2/main.go
+++ b/cmd/goflow2/main.go
@@ -15,6 +15,7 @@ import (
 	"github.com/netsampler/goflow2/format"
 	_ "github.com/netsampler/goflow2/format/json"
 	_ "github.com/netsampler/goflow2/format/protobuf"
+	_ "github.com/netsampler/goflow2/format/text"
 
 	// import various transports
 	"github.com/netsampler/goflow2/transport"
@@ -40,7 +41,6 @@ var (
 
 	Format    = flag.String("format", "json", fmt.Sprintf("Choose the format (available: %s)", strings.Join(format.GetFormats(), ", ")))
 	Transport = flag.String("transport", "file", fmt.Sprintf("Choose the transport (available: %s)", strings.Join(transport.GetTransports(), ", ")))
-	//FixedLength = flag.Bool("proto.fixedlen", false, "Enable fixed length protobuf")
 
 	MetricsAddr = flag.String("metrics.addr", ":8080", "Metrics address")
 	MetricsPath = flag.String("metrics.path", "/metrics", "Metrics path")
diff --git a/format/common/hash.go b/format/common/hash.go
new file mode 100644
index 00000000..1d901860
--- /dev/null
+++ b/format/common/hash.go
@@ -0,0 +1,56 @@
+package common
+
+import (
+	"flag"
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+)
+
+var (
+	fieldsVar string
+	fields    []string // Hashing fields
+
+	hashDeclared     bool
+	hashDeclaredLock = &sync.Mutex{}
+)
+
+func HashFlag() {
+	hashDeclaredLock.Lock()
+	defer hashDeclaredLock.Unlock()
+
+	if hashDeclared {
+		return
+	}
+	hashDeclared = true
+	flag.StringVar(&fieldsVar, "format.hash", "SamplerAddress", "List of fields to do hashing, separated by commas")
+
+}
+
+func ManualHashInit() error {
+	fields = strings.Split(fieldsVar, ",")
+	return nil
+}
+
+func HashProtoLocal(msg interface{}) string {
+	return HashProto(fields, msg)
+}
+
+func HashProto(fields []string, msg interface{}) string {
+	var keyStr string
+
+	if msg != nil {
+		vfm := reflect.ValueOf(msg)
+		vfm = reflect.Indirect(vfm)
+
+		for _, kf := range fields {
+			fieldValue := vfm.FieldByName(kf)
+			if fieldValue.IsValid() {
+				keyStr += fmt.Sprintf("%v-", fieldValue)
+			}
+		}
+	}
+
+	return keyStr
+}
diff --git a/format/common/selector.go b/format/common/selector.go
new file mode 100644
index 00000000..5c607998
--- /dev/null
+++ b/format/common/selector.go
@@ -0,0 +1,38 @@
+package common
+
+import (
+	"flag"
+	"strings"
+	"sync"
+)
+
+var (
+	selectorVar string
+	selector    []string // Hashing fields
+	selectorMap = make(map[string]bool)
+
+	selectorDeclared     bool
+	selectorDeclaredLock = &sync.Mutex{}
+)
+
+func SelectorFlag() {
+	selectorDeclaredLock.Lock()
+	defer selectorDeclaredLock.Unlock()
+
+	if selectorDeclared {
+		return
+	}
+	selectorDeclared = true
+	flag.StringVar(&selectorVar, "format.selector", "", "List of fields to do keep in output")
+}
+
+func ManualSelectorInit() error {
+	if selectorVar == "" {
+		return nil
+	}
+	selector = strings.Split(selectorVar, ",")
+	for _, v := range selector {
+		selectorMap[v] = true
+	}
+	return nil
+}
diff --git a/format/common/text.go b/format/common/text.go
new file mode 100644
index 00000000..23f7cf04
--- /dev/null
+++ b/format/common/text.go
@@ -0,0 +1,263 @@
+package common
+
+import (
+	"encoding/binary"
+	"fmt"
+	"github.com/golang/protobuf/proto"
+	"net"
+	"reflect"
+	"strings"
+)
+
+const (
+	FORMAT_TYPE_UNKNOWN = iota
+	FORMAT_TYPE_STRING_FUNC
+	FORMAT_TYPE_STRING
+	FORMAT_TYPE_INTEGER
+	FORMAT_TYPE_IP
+	FORMAT_TYPE_MAC
+)
+
+var (
+	EtypeName = map[uint32]string{
+		0x806:  "ARP",
+		0x800:  "IPv4",
+		0x86dd: "IPv6",
+	}
+	ProtoName = map[uint32]string{
+		1:  "ICMP",
+		6:  "TCP",
+		17: "UDP",
+		58: "ICMPv6",
+	}
+	IcmpTypeName = map[uint32]string{
+		0:  "EchoReply",
+		3:  "DestinationUnreachable",
+		8:  "Echo",
+		9:  "RouterAdvertisement",
+		10: "RouterSolicitation",
+		11: "TimeExceeded",
+	}
+	Icmp6TypeName = map[uint32]string{
+		1:   "DestinationUnreachable",
+		2:   "PacketTooBig",
+		3:   "TimeExceeded",
+		128: "EchoRequest",
+		129: "EchoReply",
+		133: "RouterSolicitation",
+		134: "RouterAdvertisement",
+	}
+
+	TextFields = []string{
+		"Type",
+		"TimeReceived",
+		"SequenceNum",
+		"SamplingRate",
+		"SamplerAddress",
+		"TimeFlowStart",
+		"TimeFlowEnd",
+		"Bytes",
+		"Packets",
+		"SrcAddr",
+		"DstAddr",
+		"Etype",
+		"Proto",
+		"SrcPort",
+		"DstPort",
+		"InIf",
+		"OutIf",
+		"SrcMac",
+		"DstMac",
+		"SrcVlan",
+		"DstVlan",
+		"VlanId",
+		"IngressVrfID",
+		"EgressVrfID",
+		"IPTos",
+		"ForwardingStatus",
+		"IPTTL",
+		"TCPFlags",
+		"IcmpType",
+		"IcmpCode",
+		"IPv6FlowLabel",
+		"FragmentId",
+		"FragmentOffset",
+		"BiFlowDirection",
+		"SrcAS",
+		"DstAS",
+		"NextHop",
+		"NextHopAS",
+		"SrcNet",
+		"DstNet",
+	}
+	TextFieldsTypes = []int{
+		FORMAT_TYPE_STRING_FUNC,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_IP,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_IP,
+		FORMAT_TYPE_IP,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_MAC,
+		FORMAT_TYPE_MAC,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_IP,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+		FORMAT_TYPE_INTEGER,
+	}
+	RenderExtras = []string{
+		"EtypeName",
+		"ProtoName",
+		"IcmpName",
+	}
+	RenderExtraCall = []RenderExtraFunction{
+		RenderExtraFunctionEtypeName,
+		RenderExtraFunctionProtoName,
+		RenderExtraFunctionIcmpName,
+	}
+)
+
+func AddTextField(name string, jtype int) {
+	TextFields = append(TextFields, name)
+	TextFieldsTypes = append(TextFieldsTypes, jtype)
+}
+
+type RenderExtraFunction func(proto.Message) string
+
+func RenderExtraFetchNumbers(msg proto.Message, fields []string) []uint64 {
+	vfm := reflect.ValueOf(msg)
+	vfm = reflect.Indirect(vfm)
+
+	values := make([]uint64, len(fields))
+	for i, kf := range fields {
+		fieldValue := vfm.FieldByName(kf)
+		if fieldValue.IsValid() {
+			values[i] = fieldValue.Uint()
+		}
+	}
+
+	return values
+}
+
+func RenderExtraFunctionEtypeName(msg proto.Message) string {
+	num := RenderExtraFetchNumbers(msg, []string{"Etype"})
+	return EtypeName[uint32(num[0])]
+}
+
+func RenderExtraFunctionProtoName(msg proto.Message) string {
+	num := RenderExtraFetchNumbers(msg, []string{"Proto"})
+	return ProtoName[uint32(num[0])]
+}
+func RenderExtraFunctionIcmpName(msg proto.Message) string {
+	num := RenderExtraFetchNumbers(msg, []string{"Proto", "IcmpCode", "IcmpType"})
+	return IcmpCodeType(uint32(num[0]), uint32(num[1]), uint32(num[2]))
+}
+
+func IcmpCodeType(proto, icmpCode, icmpType uint32) string {
+	if proto == 1 {
+		return IcmpTypeName[icmpType]
+	} else if proto == 58 {
+		return Icmp6TypeName[icmpType]
+	}
+	return ""
+}
+
+func RenderIP(addr []byte) string {
+	if addr == nil || (len(addr) != 4 && len(addr) != 16) {
+		return ""
+	}
+
+	return net.IP(addr).String()
+}
+
+func FormatMessageReflectText(msg proto.Message, ext string) string {
+	return FormatMessageReflectCustom(msg, ext, "", " ", "=", false)
+}
+
+func FormatMessageReflectJSON(msg proto.Message, ext string) string {
+	return fmt.Sprintf("{%s}", FormatMessageReflectCustom(msg, ext, "\"", ",", ":", true))
+}
+
+func FormatMessageReflectCustom(msg proto.Message, ext, quotes, sep, sign string, null bool) string {
+	fstr := make([]string, len(TextFields)+len(RenderExtras))
+
+	vfm := reflect.ValueOf(msg)
+	vfm = reflect.Indirect(vfm)
+
+	var i int
+	for j, kf := range TextFields {
+		fieldValue := vfm.FieldByName(kf)
+		if fieldValue.IsValid() {
+
+			switch TextFieldsTypes[j] {
+			case FORMAT_TYPE_STRING_FUNC:
+				strMethod := fieldValue.MethodByName("String").Call([]reflect.Value{})
+				fstr[i] = fmt.Sprintf("%s%s%s%s%q", quotes, kf, quotes, sign, strMethod[0].String())
+			case FORMAT_TYPE_STRING:
+				fstr[i] = fmt.Sprintf("%s%s%s%s%q", quotes, kf, quotes, sign, fieldValue.String())
+			case FORMAT_TYPE_INTEGER:
+				fstr[i] = fmt.Sprintf("%s%s%s%s%d", quotes, kf, quotes, sign, fieldValue.Uint())
+			case FORMAT_TYPE_IP:
+				ip := fieldValue.Bytes()
+				fstr[i] = fmt.Sprintf("%s%s%s%s%q", quotes, kf, quotes, sign, RenderIP(ip))
+			case FORMAT_TYPE_MAC:
+				mac := make([]byte, 8)
+				binary.BigEndian.PutUint64(mac, fieldValue.Uint())
+				fstr[i] = fmt.Sprintf("%s%s%s%s%q", quotes, kf, quotes, sign, net.HardwareAddr(mac[2:]).String())
+			default:
+				if null {
+					fstr[i] = fmt.Sprintf("%s%s%s%snull", quotes, kf, quotes, sign)
+				}
+			}
+
+		} else {
+			if null {
+				fstr[i] = fmt.Sprintf("%s%s%s%snull", quotes, kf, quotes, sign)
+			}
+		}
+		if len(selectorMap) == 0 || selectorMap[kf] {
+			i++
+		}
+
+	}
+
+	for j, e := range RenderExtras {
+		fstr[i] = fmt.Sprintf("%s%s%s%s%q", quotes, e, quotes, sign, RenderExtraCall[j](msg))
+		if len(selectorMap) == 0 || selectorMap[e] {
+			i++
+		}
+	}
+
+	if len(selectorMap) > 0 {
+		fstr = fstr[0:i]
+	}
+
+	return strings.Join(fstr, sep)
+}
diff --git a/format/json/json.go b/format/json/json.go
index 6e3205a2..f1113c52 100644
--- a/format/json/json.go
+++ b/format/json/json.go
@@ -2,215 +2,27 @@ package json
 
 import (
 	"context"
-	"encoding/binary"
 	"fmt"
 	"github.com/golang/protobuf/proto"
 	"github.com/netsampler/goflow2/format"
-	"github.com/netsampler/goflow2/format/protobuf"
-	flowmessage "github.com/netsampler/goflow2/pb"
-	"net"
-	"reflect"
-	"strings"
+	"github.com/netsampler/goflow2/format/common"
 )
 
-const (
-	FORMAT_TYPE_UNKNOWN = iota
-	FORMAT_TYPE_STRING_FUNC
-	FORMAT_TYPE_STRING
-	FORMAT_TYPE_INTEGER
-	FORMAT_TYPE_IP
-	FORMAT_TYPE_MAC
-)
-
-var (
-	EtypeName = map[uint32]string{
-		0x806:  "ARP",
-		0x800:  "IPv4",
-		0x86dd: "IPv6",
-	}
-	ProtoName = map[uint32]string{
-		1:  "ICMP",
-		6:  "TCP",
-		17: "UDP",
-		58: "ICMPv6",
-	}
-	IcmpTypeName = map[uint32]string{
-		0:  "EchoReply",
-		3:  "DestinationUnreachable",
-		8:  "Echo",
-		9:  "RouterAdvertisement",
-		10: "RouterSolicitation",
-		11: "TimeExceeded",
-	}
-	Icmp6TypeName = map[uint32]string{
-		1:   "DestinationUnreachable",
-		2:   "PacketTooBig",
-		3:   "TimeExceeded",
-		128: "EchoRequest",
-		129: "EchoReply",
-		133: "RouterSolicitation",
-		134: "RouterAdvertisement",
-	}
-
-	JsonFields = []string{
-		"Type",
-		"TimeReceived",
-		"SequenceNum",
-		"SamplingRate",
-		"SamplerAddress",
-		"TimeFlowStart",
-		"TimeFlowEnd",
-		"Bytes",
-		"Packets",
-		"SrcAddr",
-		"DstAddr",
-		"Etype",
-		"Proto",
-		"SrcPort",
-		"DstPort",
-		"InIf",
-		"OutIf",
-		"SrcMac",
-		"DstMac",
-		"SrcVlan",
-		"DstVlan",
-		"VlanId",
-		"IngressVrfID",
-		"EgressVrfID",
-		"IPTos",
-		"ForwardingStatus",
-		"IPTTL",
-		"TCPFlags",
-		"IcmpType",
-		"IcmpCode",
-		"IPv6FlowLabel",
-		"FragmentId",
-		"FragmentOffset",
-		"BiFlowDirection",
-		"SrcAS",
-		"DstAS",
-		"NextHop",
-		"NextHopAS",
-		"SrcNet",
-		"DstNet",
-	}
-	JsonFieldsTypes = []int{
-		FORMAT_TYPE_STRING_FUNC,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_IP,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_IP,
-		FORMAT_TYPE_IP,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_MAC,
-		FORMAT_TYPE_MAC,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_IP,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-		FORMAT_TYPE_INTEGER,
-	}
-	JsonExtras = []string{
-		"EtypeName",
-		"ProtoName",
-		"IcmpName",
-	}
-	JsonExtraCall = []JsonExtraFunction{
-		JsonExtraFunctionEtypeName,
-		JsonExtraFunctionProtoName,
-		JsonExtraFunctionIcmpName,
-	}
-)
-
-func AddJSONField(name string, jtype int) {
-	JsonFields = append(JsonFields, name)
-	JsonFieldsTypes = append(JsonFieldsTypes, jtype)
-}
-
-type JsonExtraFunction func(proto.Message) string
-
-func JsonExtraFetchNumbers(msg proto.Message, fields []string) []uint64 {
-	vfm := reflect.ValueOf(msg)
-	vfm = reflect.Indirect(vfm)
-
-	values := make([]uint64, len(fields))
-	for i, kf := range fields {
-		fieldValue := vfm.FieldByName(kf)
-		if fieldValue.IsValid() {
-			values[i] = fieldValue.Uint()
-		}
-	}
-
-	return values
-}
-
-func JsonExtraFunctionEtypeName(msg proto.Message) string {
-	num := JsonExtraFetchNumbers(msg, []string{"Etype"})
-	return EtypeName[uint32(num[0])]
-}
-func JsonExtraFunctionProtoName(msg proto.Message) string {
-	num := JsonExtraFetchNumbers(msg, []string{"Proto"})
-	return ProtoName[uint32(num[0])]
-}
-func JsonExtraFunctionIcmpName(msg proto.Message) string {
-	num := JsonExtraFetchNumbers(msg, []string{"Proto", "IcmpCode", "IcmpType"})
-	return IcmpCodeType(uint32(num[0]), uint32(num[1]), uint32(num[2]))
-}
-
-func IcmpCodeType(proto, icmpCode, icmpType uint32) string {
-	if proto == 1 {
-		return IcmpTypeName[icmpType]
-	} else if proto == 58 {
-		return Icmp6TypeName[icmpType]
-	}
-	return ""
-}
-
 type JsonDriver struct {
-	fieldsVar string
-	fields    []string // Hashing fields
-}
-
-func RenderIP(addr []byte) string {
-	if addr == nil || (len(addr) != 4 && len(addr) != 16) {
-		return ""
-	}
-
-	return net.IP(addr).String()
 }
 
 func (d *JsonDriver) Prepare() error {
+	common.HashFlag()
+	common.SelectorFlag()
 	return nil
 }
 
 func (d *JsonDriver) Init(context.Context) error {
-	return protobuf.ManualInit()
+	err := common.ManualHashInit()
+	if err != nil {
+		return err
+	}
+	return common.ManualSelectorInit()
 }
 
 func (d *JsonDriver) Format(data interface{}) ([]byte, []byte, error) {
@@ -219,151 +31,8 @@ func (d *JsonDriver) Format(data interface{}) ([]byte, []byte, error) {
 		return nil, nil, fmt.Errorf("message is not protobuf")
 	}
 
-	key := protobuf.HashProtoLocal(msg)
-	return []byte(key), []byte(FormatMessageReflect(msg, "")), nil
-}
-
-func FormatMessageReflect(msg proto.Message, ext string) string {
-	fstr := make([]string, len(JsonFields)+len(JsonExtras))
-
-	vfm := reflect.ValueOf(msg)
-	vfm = reflect.Indirect(vfm)
-
-	for i, kf := range JsonFields {
-		fieldValue := vfm.FieldByName(kf)
-		if fieldValue.IsValid() {
-
-			switch JsonFieldsTypes[i] {
-			case FORMAT_TYPE_STRING_FUNC:
-				strMethod := fieldValue.MethodByName("String").Call([]reflect.Value{})
-				fstr[i] = fmt.Sprintf("\"%s\":\"%s\"", kf, strMethod[0].String())
-			case FORMAT_TYPE_STRING:
-				fstr[i] = fmt.Sprintf("\"%s\":\"%s\"", kf, fieldValue.String())
-			case FORMAT_TYPE_INTEGER:
-				fstr[i] = fmt.Sprintf("\"%s\":%d", kf, fieldValue.Uint())
-			case FORMAT_TYPE_IP:
-				ip := fieldValue.Bytes()
-				fstr[i] = fmt.Sprintf("\"%s\":\"%s\"", kf, RenderIP(ip))
-			case FORMAT_TYPE_MAC:
-				mac := make([]byte, 8)
-				binary.BigEndian.PutUint64(mac, fieldValue.Uint())
-				fstr[i] = fmt.Sprintf("\"%s\":\"%s\"", kf, net.HardwareAddr(mac[2:]).String())
-			default:
-				fstr[i] = fmt.Sprintf("\"%s\":null", kf)
-			}
-
-		} else {
-			fstr[i] = fmt.Sprintf("\"%s\":null", kf)
-		}
-	}
-
-	for i, e := range JsonExtras {
-		fstr[i+len(JsonFields)] = fmt.Sprintf("\"%s\":\"%s\"", e, JsonExtraCall[i](msg))
-	}
-
-	return fmt.Sprintf("{%s}", strings.Join(fstr, ","))
-}
-
-func FormatMessage(msg *flowmessage.FlowMessage, ext string) string {
-	srcmac := make([]byte, 8)
-	dstmac := make([]byte, 8)
-	binary.BigEndian.PutUint64(srcmac, msg.SrcMac)
-	binary.BigEndian.PutUint64(dstmac, msg.DstMac)
-	srcmac = srcmac[2:8]
-	dstmac = dstmac[2:8]
-
-	b := fmt.Sprintf(
-		"{"+
-			"\"Type\":\"%v\","+
-			"\"TimeReceived\":%d,"+
-			"\"SequenceNum\":%d,"+
-			"\"SamplingRate\":%d,"+
-			"\"SamplerAddress\":\"%v\","+
-			"\"TimeFlowStart\":%d,"+
-			"\"TimeFlowEnd\":%d,"+
-			"\"Bytes\":%d,"+
-			"\"Packets\":%d,"+
-			"\"SrcAddr\":\"%v\","+
-			"\"DstAddr\":\"%v\","+
-			"\"Etype\":%d,"+
-			"\"EtypeName\":\"%s\","+
-			"\"Proto\":%d,"+
-			"\"ProtoName\":\"%s\","+
-			"\"SrcPort\":%d,"+
-			"\"DstPort\":%d,"+
-			"\"InIf\":%d,"+
-			"\"OutIf\":%d,"+
-			"\"SrcMac\":\"%v\","+
-			"\"DstMac\":\"%v\","+
-			"\"SrcVlan\":%d,"+
-			"\"DstVlan\":%d,"+
-			"\"VlanId\":%d,"+
-			"\"IngressVrfID\":%d,"+
-			"\"EgressVrfID\":%d,"+
-			"\"IPTos\":%d,"+
-			"\"ForwardingStatus\":%d,"+
-			"\"IPTTL\":%d,"+
-			"\"TCPFlags\":%d,"+
-			"\"IcmpType\":%d,"+
-			"\"IcmpCode\":%d,"+
-			"\"IcmpName\":\"%s\","+
-			"\"IPv6FlowLabel\":%d,"+
-			"\"FragmentId\":%d,"+
-			"\"FragmentOffset\":%d,"+
-			"\"BiFlowDirection\":\"%v\","+
-			"\"SrcAS\":%d,"+
-			"\"DstAS\":%d,"+
-			"\"NextHop\":\"%v\","+
-			"\"NextHopAS\":%d,"+
-			"\"SrcNet\":%d,"+
-			"\"DstNet\":%d"+
-			"%s}",
-		msg.Type.String(),
-		msg.TimeReceived,
-		msg.SequenceNum,
-		msg.SamplingRate,
-		RenderIP(msg.SamplerAddress),
-		msg.TimeFlowStart,
-		msg.TimeFlowEnd,
-		msg.Bytes,
-		msg.Packets,
-		RenderIP(msg.SrcAddr),
-		RenderIP(msg.DstAddr),
-		msg.Etype,
-		EtypeName[msg.Etype],
-		msg.Proto,
-		ProtoName[msg.Proto],
-		msg.SrcPort,
-		msg.DstPort,
-		msg.InIf,
-		msg.OutIf,
-		net.HardwareAddr(srcmac).String(),
-		net.HardwareAddr(dstmac).String(),
-		msg.SrcVlan,
-		msg.DstVlan,
-		msg.VlanId,
-		msg.IngressVrfID,
-		msg.EgressVrfID,
-		msg.IPTos,
-		msg.ForwardingStatus,
-		msg.IPTTL,
-		msg.TCPFlags,
-		msg.IcmpType,
-		msg.IcmpCode,
-		IcmpCodeType(msg.Proto, msg.IcmpCode, msg.IcmpType),
-		msg.IPv6FlowLabel,
-		msg.FragmentId,
-		msg.FragmentOffset,
-		msg.BiFlowDirection,
-		msg.SrcAS,
-		msg.DstAS,
-		RenderIP(msg.NextHop),
-		msg.NextHopAS,
-		msg.SrcNet,
-		msg.DstNet,
-		ext)
-
-	return b
+	key := common.HashProtoLocal(msg)
+	return []byte(key), []byte(common.FormatMessageReflectJSON(msg, "")), nil
 }
 
 func init() {
diff --git a/format/protobuf/protobuf.go b/format/protobuf/protobuf.go
index f8cc91f6..a59d1434 100644
--- a/format/protobuf/protobuf.go
+++ b/format/protobuf/protobuf.go
@@ -6,13 +6,7 @@ import (
 	"fmt"
 	"github.com/golang/protobuf/proto"
 	"github.com/netsampler/goflow2/format"
-	"reflect"
-	"strings"
-)
-
-var (
-	fieldsVar string
-	fields    []string // Hashing fields
+	"github.com/netsampler/goflow2/format/common"
 )
 
 type ProtobufDriver struct {
@@ -20,18 +14,13 @@ type ProtobufDriver struct {
 }
 
 func (d *ProtobufDriver) Prepare() error {
-	flag.StringVar(&fieldsVar, "format.hash", "SamplerAddress", "List of fields to do hashing, separated by commas")
+	common.HashFlag()
 	flag.BoolVar(&d.fixedLen, "format.protobuf.fixedlen", false, "Prefix the protobuf with message length")
 	return nil
 }
 
-func ManualInit() error {
-	fields = strings.Split(fieldsVar, ",")
-	return nil
-}
-
 func (d *ProtobufDriver) Init(context.Context) error {
-	return ManualInit()
+	return common.ManualHashInit()
 }
 
 func (d *ProtobufDriver) Format(data interface{}) ([]byte, []byte, error) {
@@ -39,7 +28,7 @@ func (d *ProtobufDriver) Format(data interface{}) ([]byte, []byte, error) {
 	if !ok {
 		return nil, nil, fmt.Errorf("message is not protobuf")
 	}
-	key := HashProtoLocal(msg)
+	key := common.HashProtoLocal(msg)
 
 	if !d.fixedLen {
 		b, err := proto.Marshal(msg)
@@ -55,25 +44,3 @@ func init() {
 	d := &ProtobufDriver{}
 	format.RegisterFormatDriver("pb", d)
 }
-
-func HashProtoLocal(msg interface{}) string {
-	return HashProto(fields, msg)
-}
-
-func HashProto(fields []string, msg interface{}) string {
-	var keyStr string
-
-	if msg != nil {
-		vfm := reflect.ValueOf(msg)
-		vfm = reflect.Indirect(vfm)
-
-		for _, kf := range fields {
-			fieldValue := vfm.FieldByName(kf)
-			if fieldValue.IsValid() {
-				keyStr += fmt.Sprintf("%v-", fieldValue)
-			}
-		}
-	}
-
-	return keyStr
-}
diff --git a/format/text/text.go b/format/text/text.go
new file mode 100644
index 00000000..dfb108e6
--- /dev/null
+++ b/format/text/text.go
@@ -0,0 +1,41 @@
+package text
+
+import (
+	"context"
+	"fmt"
+	"github.com/golang/protobuf/proto"
+	"github.com/netsampler/goflow2/format"
+	"github.com/netsampler/goflow2/format/common"
+)
+
+type TextDriver struct {
+}
+
+func (d *TextDriver) Prepare() error {
+	common.HashFlag()
+	common.SelectorFlag()
+	return nil
+}
+
+func (d *TextDriver) Init(context.Context) error {
+	err := common.ManualHashInit()
+	if err != nil {
+		return err
+	}
+	return common.ManualSelectorInit()
+}
+
+func (d *TextDriver) Format(data interface{}) ([]byte, []byte, error) {
+	msg, ok := data.(proto.Message)
+	if !ok {
+		return nil, nil, fmt.Errorf("message is not protobuf")
+	}
+
+	key := common.HashProtoLocal(msg)
+	return []byte(key), []byte(common.FormatMessageReflectText(msg, "")), nil
+}
+
+func init() {
+	d := &TextDriver{}
+	format.RegisterFormatDriver("text", d)
+}