diff --git a/group_test.go b/group_test.go
new file mode 100644
index 000000000..94ade836a
--- /dev/null
+++ b/group_test.go
@@ -0,0 +1,40 @@
+package goutil_test
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/gookit/goutil"
+	"github.com/gookit/goutil/netutil/httpreq"
+	"github.com/gookit/goutil/testutil/assert"
+)
+
+func TestNewErrGroup(t *testing.T) {
+	httpreq.ConfigStd(func(hc *http.Client) {
+		hc.Timeout = 3 * time.Second
+	})
+
+	eg := goutil.NewErrGroup()
+	eg.Add(func() error {
+		resp, err := httpreq.Get("https://httpbin.org/get", nil)
+		if err != nil {
+			return err
+		}
+
+		fmt.Println(resp.Body)
+		return nil
+	}, func() error {
+		resp, err := httpreq.Post("https://httpbin.org/post", "hi", nil)
+		if err != nil {
+			return err
+		}
+
+		fmt.Println(resp.Body)
+		return nil
+	})
+
+	err := eg.Wait()
+	assert.NoErr(t, err)
+}
diff --git a/strutil/padding.go b/strutil/padding.go
new file mode 100644
index 000000000..d3687f9c3
--- /dev/null
+++ b/strutil/padding.go
@@ -0,0 +1,168 @@
+package strutil
+
+import (
+	"fmt"
+	"strings"
+)
+
+// PosFlag type
+type PosFlag uint8
+
+// Position for padding/resize string
+const (
+	PosLeft PosFlag = iota
+	PosRight
+	PosMiddle
+)
+
+/*************************************************************
+ * String padding operation
+ *************************************************************/
+
+// Padding a string.
+func Padding(s, pad string, length int, pos PosFlag) string {
+	diff := len(s) - length
+	if diff >= 0 { // do not need padding.
+		return s
+	}
+
+	if pad == "" || pad == " " {
+		mark := ""
+		if pos == PosRight { // to right
+			mark = "-"
+		}
+
+		// padding left: "%7s", padding right: "%-7s"
+		tpl := fmt.Sprintf("%s%d", mark, length)
+		return fmt.Sprintf(`%`+tpl+`s`, s)
+	}
+
+	if pos == PosRight { // to right
+		return s + Repeat(pad, -diff)
+	}
+	return Repeat(pad, -diff) + s
+}
+
+// PadLeft a string.
+func PadLeft(s, pad string, length int) string {
+	return Padding(s, pad, length, PosLeft)
+}
+
+// PadRight a string.
+func PadRight(s, pad string, length int) string {
+	return Padding(s, pad, length, PosRight)
+}
+
+// Resize a string by given length and align settings. padding space.
+func Resize(s string, length int, align PosFlag) string {
+	diff := len(s) - length
+	if diff >= 0 { // do not need padding.
+		return s
+	}
+
+	if align == PosMiddle {
+		strLn := len(s)
+		padLn := (length - strLn) / 2
+		padStr := string(make([]byte, padLn, padLn))
+
+		if diff := length - padLn*2; diff > 0 {
+			s += " "
+		}
+		return padStr + s + padStr
+	}
+
+	return Padding(s, " ", length, align)
+}
+
+// PadChars padding a rune/byte to want length and with position flag
+func PadChars[T byte | rune](cs []T, pad T, length int, pos PosFlag) []T {
+	ln := len(cs)
+	if ln >= length {
+		ns := make([]T, length)
+		copy(ns, cs[:length])
+		return ns
+	}
+
+	idx := length - ln
+	ns := make([]T, length)
+	ps := RepeatChars(pad, idx)
+	if pos == PosRight {
+		copy(ns, cs)
+		copy(ns[idx:], ps)
+	} else { // to left
+		copy(ns[:idx], ps)
+		copy(ns[idx:], cs)
+	}
+
+	return ns
+}
+
+// PadBytes padding a byte to want length and with position flag
+func PadBytes(bs []byte, pad byte, length int, pos PosFlag) []byte {
+	return PadChars(bs, pad, length, pos)
+}
+
+// PadBytesLeft a byte to want length
+func PadBytesLeft(bs []byte, pad byte, length int) []byte {
+	return PadChars(bs, pad, length, PosLeft)
+}
+
+// PadBytesRight a byte to want length
+func PadBytesRight(bs []byte, pad byte, length int) []byte {
+	return PadChars(bs, pad, length, PosRight)
+}
+
+// PadRunes padding a rune to want length and with position flag
+func PadRunes(rs []rune, pad rune, length int, pos PosFlag) []rune {
+	return PadChars(rs, pad, length, pos)
+}
+
+// PadRunesLeft a rune to want length
+func PadRunesLeft(rs []rune, pad rune, length int) []rune {
+	return PadChars(rs, pad, length, PosLeft)
+}
+
+// PadRunesRight a rune to want length
+func PadRunesRight(rs []rune, pad rune, length int) []rune {
+	return PadChars(rs, pad, length, PosRight)
+}
+
+/*************************************************************
+ * String repeat operation
+ *************************************************************/
+
+// Repeat a string
+func Repeat(s string, times int) string {
+	if times <= 0 {
+		return ""
+	}
+	if times == 1 {
+		return s
+	}
+
+	ss := make([]string, 0, times)
+	for i := 0; i < times; i++ {
+		ss = append(ss, s)
+	}
+
+	return strings.Join(ss, "")
+}
+
+// RepeatRune repeat a rune char.
+func RepeatRune(char rune, times int) []rune {
+	return RepeatChars(char, times)
+}
+
+// RepeatBytes repeat a byte char.
+func RepeatBytes(char byte, times int) []byte {
+	return RepeatChars(char, times)
+}
+
+// RepeatChars repeat a byte char.
+func RepeatChars[T byte | rune](char T, times int) []T {
+	chars := make([]T, 0, times)
+	for i := 0; i < times; i++ {
+		chars = append(chars, char)
+	}
+	return chars
+}
diff --git a/strutil/padding_test.go b/strutil/padding_test.go
new file mode 100644
index 000000000..3422fa783
--- /dev/null
+++ b/strutil/padding_test.go
@@ -0,0 +1,100 @@
+package strutil_test
+
+import (
+	"testing"
+
+	"github.com/gookit/goutil/strutil"
+	"github.com/gookit/goutil/testutil/assert"
+)
+
+func TestPadding(t *testing.T) {
+	tests := []struct {
+		want, give, pad string
+		len             int
+		pos             strutil.PosFlag
+	}{
+		{"ab000", "ab", "0", 5, strutil.PosRight},
+		{"000ab", "ab", "0", 5, strutil.PosLeft},
+		{"ab012", "ab012", "0", 4, strutil.PosLeft},
+		{"ab   ", "ab", "", 5, strutil.PosRight},
+		{"   ab", "ab", "", 5, strutil.PosLeft},
+	}
+
+	for _, tt := range tests {
+		assert.Eq(t, tt.want, strutil.Padding(tt.give, tt.pad, tt.len, tt.pos))
+
+		if tt.pos == strutil.PosRight {
+			assert.Eq(t, tt.want, strutil.PadRight(tt.give, tt.pad, tt.len))
+		} else {
+			assert.Eq(t, tt.want, strutil.PadLeft(tt.give, tt.pad, tt.len))
+		}
+	}
+}
+
+func TestRepeat(t *testing.T) {
+	assert.Eq(t, "aaa", strutil.Repeat("a", 3))
+	assert.Eq(t, "DD", strutil.Repeat("D", 2))
+	assert.Eq(t, "D", strutil.Repeat("D", 1))
+	assert.Eq(t, "", strutil.Repeat("0", 0))
+	assert.Eq(t, "", strutil.Repeat("D", -3))
+}
+
+func TestRepeatRune(t *testing.T) {
+	tests := []struct {
+		want  []rune
+		give  rune
+		times int
+	}{
+		{[]rune("bbb"), 'b', 3},
+		{[]rune("..."), '.', 3},
+		{[]rune("  "), ' ', 2},
+	}
+
+	for _, tt := range tests {
+		assert.Eq(t, tt.want, strutil.RepeatRune(tt.give, tt.times))
+	}
+}
+
+func TestRepeatBytes(t *testing.T) {
+	assert.Eq(t, []byte("aaa"), strutil.RepeatBytes('a', 3))
+}
+
+func TestPadChars(t *testing.T) {
+	tests := []struct {
+		wt  []byte
+		ls  []byte
+		pad byte
+		pln int
+	}{
+		{
+			[]byte("aaaabc"), []byte("abc"), 'a', 6,
+		},
+		{
+			[]byte("abc"), []byte("abcd"), 'a', 3,
+		},
+	}
+	for _, item := range tests {
+		assert.Eq(t, item.wt, strutil.PadChars(item.ls, item.pad, item.pln, strutil.PosLeft))
+		assert.Eq(t, item.wt, strutil.PadBytes(item.ls, item.pad, item.pln, strutil.PosLeft))
+		assert.Eq(t, item.wt, strutil.PadBytesLeft(item.ls, item.pad, item.pln))
+	}
+
+	tests2 := []struct {
+		wt  []byte
+		ls  []byte
+		pad byte
+		pln int
+	}{
+		{
+			[]byte("abcaaa"), []byte("abc"), 'a', 6,
+		},
+		{
+			[]byte("abc"), []byte("abcd"), 'a', 3,
+		},
+	}
+	for _, item := range tests2 {
+		assert.Eq(t, item.wt, strutil.PadChars(item.ls, item.pad, item.pln, strutil.PosRight))
+		assert.Eq(t, item.wt, strutil.PadBytes(item.ls, item.pad, item.pln, strutil.PosRight))
+		assert.Eq(t, item.wt, strutil.PadBytesRight(item.ls, item.pad, item.pln))
+	}
+}
diff --git a/strutil/strutil.go b/strutil/strutil.go
index 9d7f45d46..ea1f69d5d 100644
--- a/strutil/strutil.go
+++ b/strutil/strutil.go
@@ -9,114 +9,6 @@ import (
 	"text/template"
 )
 
-// PosFlag type
-type PosFlag uint8
-
-// Position for padding/resize string
-const (
-	PosLeft PosFlag = iota
-	PosRight
-	PosMiddle
-)
-
-/*************************************************************
- * String padding operation
- *************************************************************/
-
-// Padding a string.
-func Padding(s, pad string, length int, pos PosFlag) string {
-	diff := len(s) - length
-	if diff >= 0 { // do not need padding.
-		return s
-	}
-
-	if pad == "" || pad == " " {
-		mark := ""
-		if pos == PosRight { // to right
-			mark = "-"
-		}
-
-		// padding left: "%7s", padding right: "%-7s"
-		tpl := fmt.Sprintf("%s%d", mark, length)
-		return fmt.Sprintf(`%`+tpl+`s`, s)
-	}
-
-	if pos == PosRight { // to right
-		return s + Repeat(pad, -diff)
-	}
-	return Repeat(pad, -diff) + s
-}
-
-// PadLeft a string.
-func PadLeft(s, pad string, length int) string {
-	return Padding(s, pad, length, PosLeft)
-}
-
-// PadRight a string.
-func PadRight(s, pad string, length int) string {
-	return Padding(s, pad, length, PosRight)
-}
-
-// Resize a string by given length and align settings. padding space.
-func Resize(s string, length int, align PosFlag) string {
-	diff := len(s) - length
-	if diff >= 0 { // do not need padding.
-		return s
-	}
-
-	if align == PosMiddle {
-		strLn := len(s)
-		padLn := (length - strLn) / 2
-		padStr := string(make([]byte, padLn, padLn))
-
-		if diff := length - padLn*2; diff > 0 {
-			s += " "
-		}
-		return padStr + s + padStr
-	}
-
-	return Padding(s, " ", length, align)
-}
-
-/*************************************************************
- * String repeat operation
- *************************************************************/
-
-// Repeat a string
-func Repeat(s string, times int) string {
-	if times <= 0 {
-		return ""
-	}
-	if times == 1 {
-		return s
-	}
-
-	ss := make([]string, 0, times)
-	for i := 0; i < times; i++ {
-		ss = append(ss, s)
-	}
-
-	return strings.Join(ss, "")
-}
-
-// RepeatRune repeat a rune char.
-func RepeatRune(char rune, times int) []rune {
-	chars := make([]rune, 0, times)
-	for i := 0; i < times; i++ {
-		chars = append(chars, char)
-	}
-	return chars
-}
-
-// RepeatBytes repeat a byte char.
-func RepeatBytes(char byte, times int) []byte {
-	chars := make([]byte, 0, times)
-	for i := 0; i < times; i++ {
-		chars = append(chars, char)
-	}
-	return chars
-}
-
 // Replaces replace multi strings
 //
 //	pairs: {old1: new1, old2: new2, ...}
diff --git a/strutil/strutil_test.go b/strutil/strutil_test.go
index 053a938f5..45f7d6661 100644
--- a/strutil/strutil_test.go
+++ b/strutil/strutil_test.go
@@ -13,34 +13,6 @@ func TestSimilarity(t *testing.T) {
 	is.True(ok)
 }
 
-func TestRepeat(t *testing.T) {
-	assert.Eq(t, "aaa", strutil.Repeat("a", 3))
-	assert.Eq(t, "DD", strutil.Repeat("D", 2))
-	assert.Eq(t, "D", strutil.Repeat("D", 1))
-	assert.Eq(t, "", strutil.Repeat("0", 0))
-	assert.Eq(t, "", strutil.Repeat("D", -3))
-}
-
-func TestRepeatRune(t *testing.T) {
-	tests := []struct {
-		want  []rune
-		give  rune
-		times int
-	}{
-		{[]rune("bbb"), 'b', 3},
-		{[]rune("..."), '.', 3},
-		{[]rune("  "), ' ', 2},
-	}
-
-	for _, tt := range tests {
-		assert.Eq(t, tt.want, strutil.RepeatRune(tt.give, tt.times))
-	}
-}
-
-func TestRepeatBytes(t *testing.T) {
-	assert.Eq(t, []byte("aaa"), strutil.RepeatBytes('a', 3))
-}
-
 func TestRenderTemplate(t *testing.T) {
 	tpl := "hi, My name is {{ .name | upFirst }}, age is {{ .age }}"
 	assert.Eq(t, "hi, My name is Inhere, age is 2000", strutil.RenderTemplate(tpl, map[string]any{
@@ -58,31 +30,8 @@ func TestReplaces(t *testing.T) {
 		}))
 }
 
-func TestPadding(t *testing.T) {
-	tests := []struct {
-		want, give, pad string
-		len             int
-		pos             strutil.PosFlag
-	}{
-		{"ab000", "ab", "0", 5, strutil.PosRight},
-		{"000ab", "ab", "0", 5, strutil.PosLeft},
-		{"ab012", "ab012", "0", 4, strutil.PosLeft},
-		{"ab   ", "ab", "", 5, strutil.PosRight},
-		{"   ab", "ab", "", 5, strutil.PosLeft},
-	}
-
-	for _, tt := range tests {
-		assert.Eq(t, tt.want, strutil.Padding(tt.give, tt.pad, tt.len, tt.pos))
-
-		if tt.pos == strutil.PosRight {
-			assert.Eq(t, tt.want, strutil.PadRight(tt.give, tt.pad, tt.len))
-		} else {
-			assert.Eq(t, tt.want, strutil.PadLeft(tt.give, tt.pad, tt.len))
-		}
-	}
-}
-
 func TestWrapTag(t *testing.T) {
+	assert.Eq(t, "<info>abc</info>", strutil.WrapTag("abc", "info"))
 }
 
 func TestPrettyJSON(t *testing.T) {