diff --git a/args.go b/args.go
index 47a97c6ac2..92e5d5aadc 100644
--- a/args.go
+++ b/args.go
@@ -633,3 +633,11 @@ func peekAllArgBytesToDst(dst [][]byte, h []argsKV, k []byte) [][]byte {
 	}
 	return dst
 }
+
+func peekArgsKeys(dst [][]byte, h []argsKV) [][]byte {
+	for i, n := 0, len(h); i < n; i++ {
+		kv := &h[i]
+		dst = append(dst, kv.key)
+	}
+	return dst
+}
diff --git a/header.go b/header.go
index fd3defdcd9..72bdc7d29b 100644
--- a/header.go
+++ b/header.go
@@ -43,6 +43,7 @@ type ResponseHeader struct {
 	contentEncoding []byte
 	server          []byte
 	mulHeader       [][]byte
+	keys            [][]byte
 
 	h       []argsKV
 	trailer []argsKV
@@ -81,6 +82,7 @@ type RequestHeader struct {
 	contentType []byte
 	userAgent   []byte
 	mulHeader   [][]byte
+	keys        [][]byte
 
 	h       []argsKV
 	trailer []argsKV
@@ -977,6 +979,7 @@ func (h *ResponseHeader) resetSkipNormalize() {
 	h.cookies = h.cookies[:0]
 	h.trailer = h.trailer[:0]
 	h.mulHeader = h.mulHeader[:0]
+	h.keys = h.keys[:0]
 }
 
 // SetNoDefaultContentType allows you to control if a default Content-Type header will be set (false) or not (true).
@@ -1006,6 +1009,7 @@ func (h *RequestHeader) resetSkipNormalize() {
 	h.userAgent = h.userAgent[:0]
 	h.trailer = h.trailer[:0]
 	h.mulHeader = h.mulHeader[:0]
+	h.keys = h.keys[:0]
 
 	h.h = h.h[:0]
 	h.cookies = h.cookies[:0]
@@ -1847,7 +1851,7 @@ func (h *RequestHeader) peekAll(key []byte) [][]byte {
 // PeekAll returns all header value for the given key.
 //
 // The returned value is valid until the request is released,
-// either though ReleaseRequest or your request handler returning.
+// either though ReleaseResponse or your request handler returning.
 // Do not store references to returned value. Make copies instead.
 func (h *ResponseHeader) PeekAll(key string) [][]byte {
 	k := getHeaderKeyBytes(&h.bufKV, key, h.disableNormalizing)
@@ -1887,6 +1891,50 @@ func (h *ResponseHeader) peekAll(key []byte) [][]byte {
 	return h.mulHeader
 }
 
+// PeekKeys return all header keys.
+//
+// The returned value is valid until the request is released,
+// either though ReleaseRequest or your request handler returning.
+// Do not store references to returned value. Make copies instead.
+func (h *RequestHeader) PeekKeys() [][]byte {
+	h.keys = h.keys[:0]
+	h.keys = peekArgsKeys(h.keys, h.h)
+	return h.keys
+}
+
+// PeekTrailerKeys return all trailer keys.
+//
+// The returned value is valid until the request is released,
+// either though ReleaseRequest or your request handler returning.
+// Do not store references to returned value. Make copies instead.
+func (h *RequestHeader) PeekTrailerKeys() [][]byte {
+	h.keys = h.keys[:0]
+	h.keys = peekArgsKeys(h.keys, h.trailer)
+	return h.keys
+}
+
+// PeekKeys return all header keys.
+//
+// The returned value is valid until the request is released,
+// either though ReleaseResponse or your request handler returning.
+// Do not store references to returned value. Make copies instead.
+func (h *ResponseHeader) PeekKeys() [][]byte {
+	h.keys = h.keys[:0]
+	h.keys = peekArgsKeys(h.keys, h.h)
+	return h.keys
+}
+
+// PeekTrailerKeys return all trailer keys.
+//
+// The returned value is valid until the request is released,
+// either though ReleaseResponse or your request handler returning.
+// Do not store references to returned value. Make copies instead.
+func (h *ResponseHeader) PeekTrailerKeys() [][]byte {
+	h.keys = h.keys[:0]
+	h.keys = peekArgsKeys(h.keys, h.trailer)
+	return h.keys
+}
+
 // Cookie returns cookie for the given key.
 func (h *RequestHeader) Cookie(key string) []byte {
 	h.collectCookies()
diff --git a/header_test.go b/header_test.go
index fdefc3c9e8..7d2942551d 100644
--- a/header_test.go
+++ b/header_test.go
@@ -2935,3 +2935,43 @@ func expectResponseHeaderAll(t *testing.T, h *ResponseHeader, key string, expect
 		t.Fatalf("Unexpected value for key %q: %q. Expected %q", key, h.PeekAll(key), expectedValue)
 	}
 }
+
+func TestRequestHeader_Keys(t *testing.T) {
+	h := &RequestHeader{}
+	h.Add(HeaderConnection, "keep-alive")
+	h.Add("Content-Type", "aaa")
+	err := h.SetTrailer("aaa,bbb,ccc")
+	if err != nil {
+		t.Fatal(err)
+	}
+	actualKeys := h.PeekKeys()
+	expectedKeys := [][]byte{s2b("keep-alive"), s2b("aaa")}
+	if reflect.DeepEqual(actualKeys, expectedKeys) {
+		t.Fatalf("Unexpected value %q. Expected %q", actualKeys, expectedKeys)
+	}
+	actualTrailerKeys := h.PeekTrailerKeys()
+	expectedTrailerKeys := [][]byte{s2b("aaa"), s2b("bbb"), s2b("ccc")}
+	if reflect.DeepEqual(actualTrailerKeys, expectedTrailerKeys) {
+		t.Fatalf("Unexpected value %q. Expected %q", actualTrailerKeys, expectedTrailerKeys)
+	}
+}
+
+func TestResponseHeader_Keys(t *testing.T) {
+	h := &ResponseHeader{}
+	h.Add(HeaderConnection, "keep-alive")
+	h.Add("Content-Type", "aaa")
+	err := h.SetTrailer("aaa,bbb,ccc")
+	if err != nil {
+		t.Fatal(err)
+	}
+	actualKeys := h.PeekKeys()
+	expectedKeys := [][]byte{s2b("keep-alive"), s2b("aaa")}
+	if reflect.DeepEqual(actualKeys, expectedKeys) {
+		t.Fatalf("Unexpected value %q. Expected %q", actualKeys, expectedKeys)
+	}
+	actualTrailerKeys := h.PeekTrailerKeys()
+	expectedTrailerKeys := [][]byte{s2b("aaa"), s2b("bbb"), s2b("ccc")}
+	if reflect.DeepEqual(actualTrailerKeys, expectedTrailerKeys) {
+		t.Fatalf("Unexpected value %q. Expected %q", actualTrailerKeys, expectedTrailerKeys)
+	}
+}