diff --git a/app.go b/app.go
index 06c29e11..efdd7265 100644
--- a/app.go
+++ b/app.go
@@ -105,6 +105,10 @@ type App struct {
 	server *fasthttp.Server
 	// App config
 	config Config
+	// Converts string to a byte slice
+	getBytes func(s string) (b []byte)
+	// Converts byte slice to a string
+	getString func(b []byte) string
 }
 
 // Config is a struct holding the server settings.
@@ -364,7 +368,9 @@ func New(config ...Config) *App {
 			},
 		},
 		// Create config
-		config: Config{},
+		config:    Config{},
+		getBytes:  utils.GetBytes,
+		getString: utils.GetString,
 	}
 	// Override config if provided
 	if len(config) > 0 {
@@ -394,7 +400,7 @@ func New(config ...Config) *App {
 		app.config.CompressedFileSuffix = DefaultCompressedFileSuffix
 	}
 	if app.config.Immutable {
-		getBytes, getString = getBytesImmutable, getStringImmutable
+		app.getBytes, app.getString = getBytesImmutable, getStringImmutable
 	}
 	if app.config.ErrorHandler == nil {
 		app.config.ErrorHandler = DefaultErrorHandler
diff --git a/app_test.go b/app_test.go
index e114d5a2..da638b8e 100644
--- a/app_test.go
+++ b/app_test.go
@@ -335,7 +335,7 @@ func Test_App_Use_UnescapedPath(t *testing.T) {
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
 	// check the param result
-	utils.AssertEqual(t, "اختبار", getString(body))
+	utils.AssertEqual(t, "اختبار", app.getString(body))
 
 	// with lowercase letters
 	resp, err = app.Test(httptest.NewRequest(MethodGet, "/cr%C3%A9er/%D8%A7%D8%AE%D8%AA%D8%A8%D8%A7%D8%B1", nil))
@@ -370,7 +370,7 @@ func Test_App_Use_CaseSensitive(t *testing.T) {
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
 	// check the detected path result
-	utils.AssertEqual(t, "/AbC", getString(body))
+	utils.AssertEqual(t, "/AbC", app.getString(body))
 }
 
 func Test_App_Add_Method_Test(t *testing.T) {
diff --git a/client.go b/client.go
index 2e6bf759..739e62f2 100644
--- a/client.go
+++ b/client.go
@@ -596,7 +596,7 @@ func (a *Agent) MultipartForm(args *Args) *Agent {
 
 	if args != nil {
 		args.VisitAll(func(key, value []byte) {
-			if err := a.mw.WriteField(getString(key), getString(value)); err != nil {
+			if err := a.mw.WriteField(utils.UnsafeString(key), utils.UnsafeString(value)); err != nil {
 				a.errs = append(a.errs, err)
 			}
 		})
@@ -785,7 +785,7 @@ func (a *Agent) Bytes() (code int, body []byte, errs []error) {
 
 func printDebugInfo(req *Request, resp *Response, w io.Writer) {
 	msg := fmt.Sprintf("Connected to %s(%s)\r\n\r\n", req.URI().Host(), resp.RemoteAddr())
-	_, _ = w.Write(getBytes(msg))
+	_, _ = w.Write(utils.UnsafeBytes(msg))
 	_, _ = req.WriteTo(w)
 	_, _ = resp.WriteTo(w)
 }
@@ -794,7 +794,7 @@ func printDebugInfo(req *Request, resp *Response, w io.Writer) {
 func (a *Agent) String() (int, string, []error) {
 	code, body, errs := a.Bytes()
 
-	return code, getString(body), errs
+	return code, utils.UnsafeString(body), errs
 }
 
 // Struct returns the status code, bytes body and errors of url.
diff --git a/ctx.go b/ctx.go
index 905f27e5..65fb2743 100644
--- a/ctx.go
+++ b/ctx.go
@@ -92,9 +92,9 @@ func (app *App) AcquireCtx(fctx *fasthttp.RequestCtx) *Ctx {
 	// Reset matched flag
 	c.matched = false
 	// Set paths
-	c.pathOriginal = getString(fctx.URI().PathOriginal())
+	c.pathOriginal = app.getString(fctx.URI().PathOriginal())
 	// Set method
-	c.method = getString(fctx.Request.Header.Method())
+	c.method = app.getString(fctx.Request.Header.Method())
 	c.methodINT = methodInt(c.method)
 	// Attach *fasthttp.RequestCtx to ctx
 	c.fasthttp = fctx
@@ -195,7 +195,7 @@ func (c *Ctx) Append(field string, values ...string) {
 	if len(values) == 0 {
 		return
 	}
-	h := getString(c.fasthttp.Response.Header.Peek(field))
+	h := c.app.getString(c.fasthttp.Response.Header.Peek(field))
 	originalH := h
 	for _, value := range values {
 		if len(h) == 0 {
@@ -216,7 +216,7 @@ func (c *Ctx) Attachment(filename ...string) {
 		fname := filepath.Base(filename[0])
 		c.Type(filepath.Ext(fname))
 
-		c.setCanonical(HeaderContentDisposition, `attachment; filename="`+quoteString(fname)+`"`)
+		c.setCanonical(HeaderContentDisposition, `attachment; filename="`+c.app.quoteString(fname)+`"`)
 		return
 	}
 	c.setCanonical(HeaderContentDisposition, "attachment")
@@ -339,7 +339,7 @@ func (c *Ctx) Cookie(cookie *Cookie) {
 // The returned value is only valid within the handler. Do not store any references.
 // Make copies or use the Immutable setting to use the value outside the Handler.
 func (c *Ctx) Cookies(key string, defaultValue ...string) string {
-	return defaultString(getString(c.fasthttp.Request.Header.Cookie(key)), defaultValue)
+	return defaultString(c.app.getString(c.fasthttp.Request.Header.Cookie(key)), defaultValue)
 }
 
 // Download transfers the file from path as an attachment.
@@ -353,7 +353,7 @@ func (c *Ctx) Download(file string, filename ...string) error {
 	} else {
 		fname = filepath.Base(file)
 	}
-	c.setCanonical(HeaderContentDisposition, `attachment; filename="`+quoteString(fname)+`"`)
+	c.setCanonical(HeaderContentDisposition, `attachment; filename="`+c.app.quoteString(fname)+`"`)
 	return c.SendFile(file)
 }
 
@@ -385,7 +385,7 @@ func (c *Ctx) Format(body interface{}) error {
 	case string:
 		b = val
 	case []byte:
-		b = getString(val)
+		b = c.app.getString(val)
 	default:
 		b = fmt.Sprintf("%v", val)
 	}
@@ -420,7 +420,7 @@ func (c *Ctx) FormFile(key string) (*multipart.FileHeader, error) {
 // Returned value is only valid within the handler. Do not store any references.
 // Make copies or use the Immutable setting instead.
 func (c *Ctx) FormValue(key string, defaultValue ...string) string {
-	return defaultString(getString(c.fasthttp.FormValue(key)), defaultValue)
+	return defaultString(c.app.getString(c.fasthttp.FormValue(key)), defaultValue)
 }
 
 // Fresh returns true when the response is still “fresh” in the client's cache,
@@ -449,16 +449,16 @@ func (c *Ctx) Fresh() bool {
 
 	// if-none-match
 	if noneMatch != "" && noneMatch != "*" {
-		var etag = getString(c.fasthttp.Response.Header.Peek(HeaderETag))
+		var etag = c.app.getString(c.fasthttp.Response.Header.Peek(HeaderETag))
 		if etag == "" {
 			return false
 		}
-		if isEtagStale(etag, getBytes(noneMatch)) {
+		if c.app.isEtagStale(etag, c.app.getBytes(noneMatch)) {
 			return false
 		}
 
 		if modifiedSince != "" {
-			var lastModified = getString(c.fasthttp.Response.Header.Peek(HeaderLastModified))
+			var lastModified = c.app.getString(c.fasthttp.Response.Header.Peek(HeaderLastModified))
 			if lastModified != "" {
 				lastModifiedTime, err := http.ParseTime(lastModified)
 				if err != nil {
@@ -480,14 +480,14 @@ func (c *Ctx) Fresh() bool {
 // Returned value is only valid within the handler. Do not store any references.
 // Make copies or use the Immutable setting instead.
 func (c *Ctx) Get(key string, defaultValue ...string) string {
-	return defaultString(getString(c.fasthttp.Request.Header.Peek(key)), defaultValue)
+	return defaultString(c.app.getString(c.fasthttp.Request.Header.Peek(key)), defaultValue)
 }
 
 // Hostname contains the hostname derived from the Host HTTP header.
 // Returned value is only valid within the handler. Do not store any references.
 // Make copies or use the Immutable setting instead.
 func (c *Ctx) Hostname() string {
-	return getString(c.fasthttp.Request.URI().Host())
+	return c.app.getString(c.fasthttp.Request.URI().Host())
 }
 
 // IP returns the remote IP address of the request.
@@ -509,10 +509,10 @@ func (c *Ctx) IPs() (ips []string) {
 	for {
 		commaPos = bytes.IndexByte(header, ',')
 		if commaPos != -1 {
-			ips[i] = utils.Trim(getString(header[:commaPos]), ' ')
+			ips[i] = utils.Trim(c.app.getString(header[:commaPos]), ' ')
 			header, i = header[commaPos+1:], i+1
 		} else {
-			ips[i] = utils.Trim(getString(header), ' ')
+			ips[i] = utils.Trim(c.app.getString(header), ' ')
 			return
 		}
 	}
@@ -565,7 +565,7 @@ func (c *Ctx) JSONP(data interface{}, callback ...string) error {
 		cb = "callback"
 	}
 
-	result = cb + "(" + getString(raw) + ");"
+	result = cb + "(" + c.app.getString(raw) + ");"
 
 	c.setCanonical(HeaderXContentTypeOptions, "nosniff")
 	c.fasthttp.Response.Header.SetContentType(MIMEApplicationJavaScriptCharsetUTF8)
@@ -587,7 +587,7 @@ func (c *Ctx) Links(link ...string) {
 			_, _ = bb.WriteString(`; rel="` + link[i] + `",`)
 		}
 	}
-	c.setCanonical(HeaderLink, utils.TrimRight(getString(bb.Bytes()), ','))
+	c.setCanonical(HeaderLink, utils.TrimRight(c.app.getString(bb.Bytes()), ','))
 	bytebufferpool.Put(bb)
 }
 
@@ -645,7 +645,7 @@ func (c *Ctx) Next() (err error) {
 // Returned value is only valid within the handler. Do not store any references.
 // Make copies or use the Immutable setting to use the value outside the Handler.
 func (c *Ctx) OriginalURL() string {
-	return getString(c.fasthttp.Request.Header.RequestURI())
+	return c.app.getString(c.fasthttp.Request.Header.RequestURI())
 }
 
 // Params is used to get the route parameters.
@@ -706,14 +706,14 @@ func (c *Ctx) Protocol() string {
 			return // X-Forwarded-
 		} else if bytes.HasPrefix(key, []byte("X-Forwarded-")) {
 			if bytes.Equal(key, []byte(HeaderXForwardedProto)) {
-				scheme = getString(val)
+				scheme = c.app.getString(val)
 			} else if bytes.Equal(key, []byte(HeaderXForwardedProtocol)) {
-				scheme = getString(val)
+				scheme = c.app.getString(val)
 			} else if bytes.Equal(key, []byte(HeaderXForwardedSsl)) && bytes.Equal(val, []byte("on")) {
 				scheme = "https"
 			}
 		} else if bytes.Equal(key, []byte(HeaderXUrlScheme)) {
-			scheme = getString(val)
+			scheme = c.app.getString(val)
 		}
 	})
 	return scheme
@@ -725,7 +725,7 @@ func (c *Ctx) Protocol() string {
 // Returned value is only valid within the handler. Do not store any references.
 // Make copies or use the Immutable setting to use the value outside the Handler.
 func (c *Ctx) Query(key string, defaultValue ...string) string {
-	return defaultString(getString(c.fasthttp.QueryArgs().Peek(key)), defaultValue)
+	return defaultString(c.app.getString(c.fasthttp.QueryArgs().Peek(key)), defaultValue)
 }
 
 // QueryParser binds the query string to a struct.
@@ -882,7 +882,7 @@ func (c *Ctx) Render(name string, bind interface{}, layouts ...string) error {
 			return err
 		}
 		// Parse template
-		if tmpl, err = template.New("").Parse(getString(buf.Bytes())); err != nil {
+		if tmpl, err = template.New("").Parse(c.app.getString(buf.Bytes())); err != nil {
 			return err
 		}
 		buf.Reset()
@@ -1124,7 +1124,7 @@ func (c *Ctx) configDependentPaths() {
 	if c.app.config.UnescapePath {
 		c.pathBuffer = fasthttp.AppendUnquotedArg(c.pathBuffer[:0], c.pathBuffer)
 	}
-	c.path = getString(c.pathBuffer)
+	c.path = c.app.getString(c.pathBuffer)
 
 	// another path is specified which is for routing recognition only
 	// use the path that was changed by the previous configuration flags
@@ -1137,7 +1137,7 @@ func (c *Ctx) configDependentPaths() {
 	if !c.app.config.StrictRouting && len(c.detectionPathBuffer) > 1 && c.detectionPathBuffer[len(c.detectionPathBuffer)-1] == '/' {
 		c.detectionPathBuffer = utils.TrimRightBytes(c.detectionPathBuffer, '/')
 	}
-	c.detectionPath = getString(c.detectionPathBuffer)
+	c.detectionPath = c.app.getString(c.detectionPathBuffer)
 
 	// Define the path for dividing routes into areas for fast tree detection, so that fewer routes need to be traversed,
 	// since the first three characters area select a list of routes
diff --git a/ctx_test.go b/ctx_test.go
index 97936b27..cf0d4132 100644
--- a/ctx_test.go
+++ b/ctx_test.go
@@ -229,7 +229,7 @@ func Benchmark_Ctx_Append(b *testing.B) {
 		c.Append("X-Custom-Header", "World")
 		c.Append("X-Custom-Header", "Hello")
 	}
-	utils.AssertEqual(b, "Hello, World", getString(c.Response().Header.Peek("X-Custom-Header")))
+	utils.AssertEqual(b, "Hello, World", app.getString(c.Response().Header.Peek("X-Custom-Header")))
 }
 
 // go test -run Test_Ctx_Attachment
@@ -481,7 +481,7 @@ func Benchmark_Ctx_Cookie(b *testing.B) {
 			Value: "Doe",
 		})
 	}
-	utils.AssertEqual(b, "John=Doe; path=/; SameSite=Lax", getString(c.Response().Header.Peek("Set-Cookie")))
+	utils.AssertEqual(b, "John=Doe; path=/; SameSite=Lax", app.getString(c.Response().Header.Peek("Set-Cookie")))
 }
 
 // go test -run Test_Ctx_Cookies
diff --git a/helpers.go b/helpers.go
index a0f8d161..30b3101f 100644
--- a/helpers.go
+++ b/helpers.go
@@ -95,10 +95,10 @@ func readContent(rf io.ReaderFrom, name string) (n int64, err error) {
 }
 
 // quoteString escape special characters in a given string
-func quoteString(raw string) string {
+func (app *App) quoteString(raw string) string {
 	bb := bytebufferpool.Get()
 	// quoted := string(fasthttp.AppendQuotedArg(bb.B, getBytes(raw)))
-	quoted := getString(fasthttp.AppendQuotedArg(bb.B, getBytes(raw)))
+	quoted := app.getString(fasthttp.AppendQuotedArg(bb.B, app.getBytes(raw)))
 	bytebufferpool.Put(bb)
 	return quoted
 }
@@ -272,7 +272,7 @@ func matchEtag(s string, etag string) bool {
 	return false
 }
 
-func isEtagStale(etag string, noneMatchBytes []byte) bool {
+func (app *App) isEtagStale(etag string, noneMatchBytes []byte) bool {
 	var start, end int
 
 	// Adapted from:
@@ -285,7 +285,7 @@ func isEtagStale(etag string, noneMatchBytes []byte) bool {
 				end = i + 1
 			}
 		case 0x2c:
-			if matchEtag(getString(noneMatchBytes[start:end]), etag) {
+			if matchEtag(app.getString(noneMatchBytes[start:end]), etag) {
 				return false
 			}
 			start = i + 1
@@ -295,7 +295,7 @@ func isEtagStale(etag string, noneMatchBytes []byte) bool {
 		}
 	}
 
-	return !matchEtag(getString(noneMatchBytes[start:end]), etag)
+	return !matchEtag(app.getString(noneMatchBytes[start:end]), etag)
 }
 
 func parseAddr(raw string) (host, port string) {
@@ -359,14 +359,10 @@ func (c *testConn) SetDeadline(_ time.Time) error      { return nil }
 func (c *testConn) SetReadDeadline(_ time.Time) error  { return nil }
 func (c *testConn) SetWriteDeadline(_ time.Time) error { return nil }
 
-// getString converts byte slice to a string without memory allocation.
-var getString = utils.UnsafeString
 var getStringImmutable = func(b []byte) string {
 	return string(b)
 }
 
-// getBytes converts string to a byte slice without memory allocation.
-var getBytes = utils.UnsafeBytes
 var getBytesImmutable = func(s string) (b []byte) {
 	return []byte(s)
 }
diff --git a/helpers_test.go b/helpers_test.go
index 1600ce76..291d49a0 100644
--- a/helpers_test.go
+++ b/helpers_test.go
@@ -182,9 +182,9 @@ func Benchmark_Utils_Unescape(b *testing.B) {
 
 	for n := 0; n < b.N; n++ {
 		source := "/cr%C3%A9er"
-		pathBytes := getBytes(source)
+		pathBytes := utils.UnsafeBytes(source)
 		pathBytes = fasthttp.AppendUnquotedArg(dst[:0], pathBytes)
-		unescaped = getString(pathBytes)
+		unescaped = utils.UnsafeString(pathBytes)
 	}
 
 	utils.AssertEqual(b, "/créer", unescaped)
diff --git a/router.go b/router.go
index c8765e3b..b842307c 100644
--- a/router.go
+++ b/router.go
@@ -325,7 +325,7 @@ func (app *App) registerStatic(prefix, root string, config ...Static) Router {
 		PathRewrite: func(fctx *fasthttp.RequestCtx) []byte {
 			path := fctx.Path()
 			if len(path) >= prefixLen {
-				if isStar && getString(path[0:prefixLen]) == prefix {
+				if isStar && app.getString(path[0:prefixLen]) == prefix {
 					path = append(path[0:0], '/')
 				} else if len(path) > 0 && path[len(path)-1] != '/' {
 					path = append(path[prefixLen:], '/')
diff --git a/router_test.go b/router_test.go
index 01509ba9..bebcc30d 100644
--- a/router_test.go
+++ b/router_test.go
@@ -43,7 +43,7 @@ func Test_Route_Match_SameLength(t *testing.T) {
 
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, ":param", getString(body))
+	utils.AssertEqual(t, ":param", app.getString(body))
 
 	// with param
 	resp, err = app.Test(httptest.NewRequest(MethodGet, "/test", nil))
@@ -52,7 +52,7 @@ func Test_Route_Match_SameLength(t *testing.T) {
 
 	body, err = ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "test", getString(body))
+	utils.AssertEqual(t, "test", app.getString(body))
 }
 
 func Test_Route_Match_Star(t *testing.T) {
@@ -68,7 +68,7 @@ func Test_Route_Match_Star(t *testing.T) {
 
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "*", getString(body))
+	utils.AssertEqual(t, "*", app.getString(body))
 
 	// with param
 	resp, err = app.Test(httptest.NewRequest(MethodGet, "/test", nil))
@@ -77,7 +77,7 @@ func Test_Route_Match_Star(t *testing.T) {
 
 	body, err = ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "test", getString(body))
+	utils.AssertEqual(t, "test", app.getString(body))
 
 	// without parameter
 	route := Route{
@@ -114,7 +114,7 @@ func Test_Route_Match_Root(t *testing.T) {
 
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "root", getString(body))
+	utils.AssertEqual(t, "root", app.getString(body))
 }
 
 func Test_Route_Match_Parser(t *testing.T) {
@@ -132,7 +132,7 @@ func Test_Route_Match_Parser(t *testing.T) {
 
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "bar", getString(body))
+	utils.AssertEqual(t, "bar", app.getString(body))
 
 	// with star
 	resp, err = app.Test(httptest.NewRequest(MethodGet, "/Foobar/test", nil))
@@ -141,7 +141,7 @@ func Test_Route_Match_Parser(t *testing.T) {
 
 	body, err = ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "test", getString(body))
+	utils.AssertEqual(t, "test", app.getString(body))
 }
 
 func Test_Route_Match_Middleware(t *testing.T) {
@@ -157,7 +157,7 @@ func Test_Route_Match_Middleware(t *testing.T) {
 
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "*", getString(body))
+	utils.AssertEqual(t, "*", app.getString(body))
 
 	// with param
 	resp, err = app.Test(httptest.NewRequest(MethodGet, "/foo/bar/fasel", nil))
@@ -166,7 +166,7 @@ func Test_Route_Match_Middleware(t *testing.T) {
 
 	body, err = ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "bar/fasel", getString(body))
+	utils.AssertEqual(t, "bar/fasel", app.getString(body))
 }
 
 func Test_Route_Match_UnescapedPath(t *testing.T) {
@@ -182,7 +182,7 @@ func Test_Route_Match_UnescapedPath(t *testing.T) {
 
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "test", getString(body))
+	utils.AssertEqual(t, "test", app.getString(body))
 	// without special chars
 	resp, err = app.Test(httptest.NewRequest(MethodGet, "/créer", nil))
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
@@ -208,7 +208,7 @@ func Test_Route_Match_Middleware_HasPrefix(t *testing.T) {
 
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "middleware", getString(body))
+	utils.AssertEqual(t, "middleware", app.getString(body))
 }
 
 func Test_Route_Match_Middleware_Root(t *testing.T) {
@@ -224,7 +224,7 @@ func Test_Route_Match_Middleware_Root(t *testing.T) {
 
 	body, err := ioutil.ReadAll(resp.Body)
 	utils.AssertEqual(t, nil, err, "app.Test(req)")
-	utils.AssertEqual(t, "middleware", getString(body))
+	utils.AssertEqual(t, "middleware", app.getString(body))
 }
 
 func Test_Router_Register_Missing_Handler(t *testing.T) {