diff --git a/ext/iodine/http.c b/ext/iodine/http.c
index 9607f09..8283310 100644
--- a/ext/iodine/http.c
+++ b/ext/iodine/http.c
@@ -834,6 +834,8 @@ static http_settings_s *http_settings_new(http_settings_s arg_settings) {
     if ((ssize_t)arg_settings.max_clients - HTTP_BUSY_UNLESS_HAS_FDS > 0)
       arg_settings.max_clients -= HTTP_BUSY_UNLESS_HAS_FDS;
   }
+  if (!arg_settings.deflate)
+    arg_settings.deflate = (size_t)-1;
 
   http_settings_s *settings = malloc(sizeof(*settings) + sizeof(void *));
   *settings = arg_settings;
diff --git a/ext/iodine/http.h b/ext/iodine/http.h
index e13a8e2..ab61e4c 100644
--- a/ext/iodine/http.h
+++ b/ext/iodine/http.h
@@ -403,6 +403,8 @@ struct http_settings_s {
   uint8_t log;
   /** a read only flag set automatically to indicate the protocol's mode. */
   uint8_t is_client;
+  /** minimum size of a message to deflate. Defaults to -1 bytes which means no deflation. */
+  size_t deflate;
 };
 
 /**
@@ -543,6 +545,7 @@ typedef struct {
   void (*on_close)(intptr_t uuid, void *udata);
   /** Opaque user data. */
   void *udata;
+  size_t deflate;
 } websocket_settings_s;
 
 /**
diff --git a/ext/iodine/http1.c b/ext/iodine/http1.c
index cbf4b6c..2bcb48e 100644
--- a/ext/iodine/http1.c
+++ b/ext/iodine/http1.c
@@ -349,6 +349,10 @@ static int http1_http2websocket_server(http_s *h, websocket_settings_s *args) {
   stmp = fiobj_obj2cstr(tmp);
   fiobj_str_resize(tmp,
                    fio_base64_encode(stmp.data, fio_sha1_result(&sha1), 20));
+
+  if (args->deflate != (size_t)-1) {
+    http_set_header(h, HTTP_HEADER_WS_SEC_EXTENSIONS, fiobj_dup(HTTP_HVALUE_WS_DEFLATE));
+  }
   http_set_header(h, HTTP_HEADER_CONNECTION, fiobj_dup(HTTP_HVALUE_WS_UPGRADE));
   http_set_header(h, HTTP_HEADER_UPGRADE, fiobj_dup(HTTP_HVALUE_WEBSOCKET));
   http_set_header(h, HTTP_HEADER_WS_SEC_KEY, tmp);
diff --git a/ext/iodine/http_internal.c b/ext/iodine/http_internal.c
index f3058d3..2b69b5b 100644
--- a/ext/iodine/http_internal.c
+++ b/ext/iodine/http_internal.c
@@ -126,6 +126,7 @@ FIOBJ HTTP_HEADER_ORIGIN;
 FIOBJ HTTP_HEADER_SET_COOKIE;
 FIOBJ HTTP_HEADER_UPGRADE;
 FIOBJ HTTP_HEADER_WS_SEC_CLIENT_KEY;
+FIOBJ HTTP_HEADER_WS_SEC_EXTENSIONS;
 FIOBJ HTTP_HEADER_WS_SEC_KEY;
 FIOBJ HTTP_HVALUE_BYTES;
 FIOBJ HTTP_HVALUE_CLOSE;
@@ -136,6 +137,7 @@ FIOBJ HTTP_HVALUE_MAX_AGE;
 FIOBJ HTTP_HVALUE_NO_CACHE;
 FIOBJ HTTP_HVALUE_SSE_MIME;
 FIOBJ HTTP_HVALUE_WEBSOCKET;
+FIOBJ HTTP_HVALUE_WS_DEFLATE;
 FIOBJ HTTP_HVALUE_WS_SEC_VERSION;
 FIOBJ HTTP_HVALUE_WS_UPGRADE;
 FIOBJ HTTP_HVALUE_WS_VERSION;
@@ -172,6 +174,7 @@ static void http_lib_cleanup(void *ignr_) {
   HTTPLIB_RESET(HTTP_HEADER_SET_COOKIE);
   HTTPLIB_RESET(HTTP_HEADER_UPGRADE);
   HTTPLIB_RESET(HTTP_HEADER_WS_SEC_CLIENT_KEY);
+  HTTPLIB_RESET(HTTP_HEADER_WS_SEC_EXTENSIONS);
   HTTPLIB_RESET(HTTP_HEADER_WS_SEC_KEY);
   HTTPLIB_RESET(HTTP_HVALUE_BYTES);
   HTTPLIB_RESET(HTTP_HVALUE_CLOSE);
@@ -182,6 +185,7 @@ static void http_lib_cleanup(void *ignr_) {
   HTTPLIB_RESET(HTTP_HVALUE_NO_CACHE);
   HTTPLIB_RESET(HTTP_HVALUE_SSE_MIME);
   HTTPLIB_RESET(HTTP_HVALUE_WEBSOCKET);
+  HTTPLIB_RESET(HTTP_HVALUE_WS_DEFLATE);
   HTTPLIB_RESET(HTTP_HVALUE_WS_SEC_VERSION);
   HTTPLIB_RESET(HTTP_HVALUE_WS_UPGRADE);
   HTTPLIB_RESET(HTTP_HVALUE_WS_VERSION);
@@ -213,6 +217,7 @@ static void http_lib_init(void *ignr_) {
   HTTP_HEADER_SET_COOKIE = fiobj_str_new("set-cookie", 10);
   HTTP_HEADER_UPGRADE = fiobj_str_new("upgrade", 7);
   HTTP_HEADER_WS_SEC_CLIENT_KEY = fiobj_str_new("sec-websocket-key", 17);
+  HTTP_HEADER_WS_SEC_EXTENSIONS = fiobj_str_new("sec-websocket-extensions", 24);
   HTTP_HEADER_WS_SEC_KEY = fiobj_str_new("sec-websocket-accept", 20);
   HTTP_HVALUE_BYTES = fiobj_str_new("bytes", 5);
   HTTP_HVALUE_CLOSE = fiobj_str_new("close", 5);
@@ -224,6 +229,7 @@ static void http_lib_init(void *ignr_) {
   HTTP_HVALUE_NO_CACHE = fiobj_str_new("no-cache, max-age=0", 19);
   HTTP_HVALUE_SSE_MIME = fiobj_str_new("text/event-stream", 17);
   HTTP_HVALUE_WEBSOCKET = fiobj_str_new("websocket", 9);
+  HTTP_HVALUE_WS_DEFLATE = fiobj_str_new("permessage-deflate", 18);
   HTTP_HVALUE_WS_SEC_VERSION = fiobj_str_new("sec-websocket-version", 21);
   HTTP_HVALUE_WS_UPGRADE = fiobj_str_new("Upgrade", 7);
   HTTP_HVALUE_WS_VERSION = fiobj_str_new("13", 2);
diff --git a/ext/iodine/http_internal.h b/ext/iodine/http_internal.h
index 4002c02..8783bed 100644
--- a/ext/iodine/http_internal.h
+++ b/ext/iodine/http_internal.h
@@ -72,6 +72,7 @@ Constants that shouldn't be accessed by the users (`fiobj_dup` required).
 
 extern FIOBJ HTTP_HEADER_ACCEPT_RANGES;
 extern FIOBJ HTTP_HEADER_WS_SEC_CLIENT_KEY;
+extern FIOBJ HTTP_HEADER_WS_SEC_EXTENSIONS;
 extern FIOBJ HTTP_HEADER_WS_SEC_KEY;
 extern FIOBJ HTTP_HVALUE_BYTES;
 extern FIOBJ HTTP_HVALUE_CLOSE;
@@ -82,6 +83,7 @@ extern FIOBJ HTTP_HVALUE_MAX_AGE;
 extern FIOBJ HTTP_HVALUE_NO_CACHE;
 extern FIOBJ HTTP_HVALUE_SSE_MIME;
 extern FIOBJ HTTP_HVALUE_WEBSOCKET;
+extern FIOBJ HTTP_HVALUE_WS_DEFLATE;
 extern FIOBJ HTTP_HVALUE_WS_SEC_VERSION;
 extern FIOBJ HTTP_HVALUE_WS_UPGRADE;
 extern FIOBJ HTTP_HVALUE_WS_VERSION;
diff --git a/ext/iodine/iodine.c b/ext/iodine/iodine.c
index 67d38a1..b12b24b 100644
--- a/ext/iodine/iodine.c
+++ b/ext/iodine/iodine.c
@@ -49,6 +49,7 @@ static VALUE max_msg_sym;
 static VALUE method_sym;
 static VALUE path_sym;
 static VALUE ping_sym;
+static VALUE deflate_sym;
 static VALUE port_sym;
 static VALUE public_sym;
 static VALUE service_sym;
@@ -414,6 +415,8 @@ static VALUE iodine_cli_parse(VALUE self) {
       FIO_CLI_INT("-max-msg -maxms incoming WebSocket message limit in Kb. "
                   "Default: 250Kb"),
       FIO_CLI_INT("-ping websocket ping interval (1..255). Default: 40s"),
+      FIO_CLI_INT("-deflate minimum size of outgoing message to deflate. Default: -1. "
+                  "-1 turns off deflation."),
       FIO_CLI_PRINT_HEADER("SSL/TLS:"),
       FIO_CLI_BOOL("-tls enable SSL/TLS using a self-signed certificate."),
       FIO_CLI_STRING(
@@ -503,6 +506,9 @@ static VALUE iodine_cli_parse(VALUE self) {
   if (fio_cli_get("-ping")) {
     rb_hash_aset(defaults, ping_sym, INT2NUM(fio_cli_get_i("-ping")));
   }
+  if (fio_cli_get("-deflate")) {
+    rb_hash_aset(defaults, deflate_sym, INT2NUM(fio_cli_get_i("-deflate")));
+  }
   if (fio_cli_get("-redis-ping")) {
     rb_hash_aset(defaults, ID2SYM(rb_intern("redis_ping_")),
                  INT2NUM(fio_cli_get_i("-redis-ping")));
@@ -659,6 +665,7 @@ Supported Settigs:
 - `:public` (public folder, HTTP server only)
 - `:timeout` (HTTP only)
 - `:ping` (`:raw` clients and WebSockets only)
+- `:deflate` (`:raw` WebSockets only)
 - `:max_headers` (HTTP only)
 - `:max_body` (HTTP only)
 - `:max_msg` (WebSockets only)
@@ -682,6 +689,7 @@ FIO_FUNC iodine_connection_args_s iodine_connect_args(VALUE s, uint8_t is_srv) {
   VALUE method = rb_hash_aref(s, method_sym);
   VALUE path = rb_hash_aref(s, path_sym);
   VALUE ping = rb_hash_aref(s, ping_sym);
+  VALUE deflate = rb_hash_aref(s, deflate_sym);
   VALUE port = rb_hash_aref(s, port_sym);
   VALUE r_public = rb_hash_aref(s, public_sym);
   VALUE service = rb_hash_aref(s, service_sym);
@@ -717,6 +725,8 @@ FIO_FUNC iodine_connection_args_s iodine_connect_args(VALUE s, uint8_t is_srv) {
     path = rb_hash_aref(iodine_default_args, path_sym);
   if (ping == Qnil)
     ping = rb_hash_aref(iodine_default_args, ping_sym);
+  if (deflate == Qnil)
+    deflate = rb_hash_aref(iodine_default_args, deflate_sym);
   if (port == Qnil)
     port = rb_hash_aref(iodine_default_args, port_sym);
   if (r_public == Qnil) {
@@ -792,6 +802,9 @@ FIO_FUNC iodine_connection_args_s iodine_connect_args(VALUE s, uint8_t is_srv) {
     else
       r.ping = FIX2ULONG(ping);
   }
+  if (deflate != Qnil && RB_TYPE_P(deflate, T_FIXNUM)) {
+    r.deflate = FIX2LONG(deflate);
+  }
   if (port != Qnil) {
     if (RB_TYPE_P(port, T_STRING)) {
       char *tmp = RSTRING_PTR(port);
@@ -1285,6 +1298,7 @@ void Init_iodine(void) {
   IODINE_MAKE_SYM(method);
   IODINE_MAKE_SYM(path);
   IODINE_MAKE_SYM(ping);
+  IODINE_MAKE_SYM(deflate);
   IODINE_MAKE_SYM(port);
   IODINE_MAKE_SYM(public);
   IODINE_MAKE_SYM(service);
diff --git a/ext/iodine/iodine.h b/ext/iodine/iodine.h
index 5757aa5..d6cc2c4 100644
--- a/ext/iodine/iodine.h
+++ b/ext/iodine/iodine.h
@@ -26,6 +26,7 @@ typedef struct {
   uint8_t timeout;
   uint8_t ping;
   uint8_t log;
+  size_t deflate;
   enum {
     IODINE_SERVICE_RAW,
     IODINE_SERVICE_HTTP,
diff --git a/ext/iodine/iodine_connection.c b/ext/iodine/iodine_connection.c
index 6931195..2b82cb3 100644
--- a/ext/iodine/iodine_connection.c
+++ b/ext/iodine/iodine_connection.c
@@ -900,7 +900,7 @@ void iodine_connection_init(void) {
   IodineStore.add(RAWSymbol);
 
   // define the Connection Class and it's methods
-  ConnectionKlass = rb_define_class_under(IodineModule, "Connection", rb_cData);
+  ConnectionKlass = rb_define_class_under(IodineModule, "Connection", rb_cObject);
   rb_define_alloc_func(ConnectionKlass, iodine_connection_data_alloc_c);
   rb_define_method(ConnectionKlass, "write", iodine_connection_write, 1);
   rb_define_method(ConnectionKlass, "close", iodine_connection_close, 0);
diff --git a/ext/iodine/iodine_http.c b/ext/iodine/iodine_http.c
index 70bbd9d..53207d7 100644
--- a/ext/iodine/iodine_http.c
+++ b/ext/iodine/iodine_http.c
@@ -7,6 +7,7 @@ Feel free to copy, use and enjoy according to the license provided.
 #include "iodine.h"
 
 #include "http.h"
+#include "http_internal.h"
 
 #include <ruby/encoding.h>
 #include <ruby/io.h>
@@ -34,6 +35,7 @@ VALUE IODINE_R_HIJACK;
 VALUE IODINE_R_HIJACK_IO;
 VALUE IODINE_R_HIJACK_CB;
 
+static VALUE RACK_WS_EXTENSIONS;
 static VALUE RACK_UPGRADE;
 static VALUE RACK_UPGRADE_Q;
 static VALUE RACK_UPGRADE_SSE;
@@ -193,16 +195,31 @@ static void iodine_ws_on_close(intptr_t uuid, void *udata) {
 }
 
 static void iodine_ws_attach(http_s *h, VALUE handler, VALUE env) {
+  http_settings_s *http_settings = (http_settings_s *)((http_fio_protocol_s *)h->private_data.flag)->settings;
+
   VALUE io =
       iodine_connection_new(.type = IODINE_CONNECTION_WEBSOCKET, .arg = NULL,
                             .handler = handler, .env = env, .uuid = 0);
   if (io == Qnil)
     return;
 
+  size_t deflate = (size_t)-1;
+
+  // check if permessage-deflate allowed
+  // must have header from client for extensions
+  // must have the permessage-deflate extension requested
+  // must have server authorize deflation
+  VALUE extension_header = rb_hash_aref(env, RACK_WS_EXTENSIONS);
+  char *extensions = (extension_header == Qnil ? NULL : StringValueCStr(extension_header));
+  if (http_settings->deflate >= 0 && extensions != NULL && strcasestr(extensions, "permessage-deflate") != NULL) {
+    deflate = http_settings->deflate;
+  }
+
   http_upgrade2ws(h, .on_message = iodine_ws_on_message,
                   .on_open = iodine_ws_on_open, .on_ready = iodine_ws_on_ready,
                   .on_shutdown = iodine_ws_on_shutdown,
-                  .on_close = iodine_ws_on_close, .udata = (void *)io);
+                  .on_close = iodine_ws_on_close, .udata = (void *)io,
+                  .deflate = deflate);
 }
 
 /* *****************************************************************************
@@ -944,7 +961,8 @@ intptr_t iodine_http_listen(iodine_connection_args_s args){
       .tls = args.tls, .timeout = args.timeout, .ws_timeout = args.ping,
       .ws_max_msg_size = args.max_msg, .max_header_size = args.max_headers,
       .on_finish = free_iodine_http, .log = args.log,
-      .max_body_size = args.max_body, .public_folder = args.public.data);
+      .max_body_size = args.max_body, .public_folder = args.public.data,
+      .deflate = args.deflate);
   if (uuid == -1)
     return uuid;
 
@@ -1120,6 +1138,7 @@ void iodine_init_http(void) {
   rack_set(IODINE_R_HIJACK, "rack.hijack");
   rack_set(IODINE_R_HIJACK_CB, "iodine.hijack_cb");
 
+  rack_set(RACK_WS_EXTENSIONS, "HTTP_SEC_WEBSOCKET_EXTENSIONS");
   rack_set(RACK_UPGRADE, "rack.upgrade");
   rack_set(RACK_UPGRADE_Q, "rack.upgrade?");
   rack_set_sym(RACK_UPGRADE_SSE, "sse");
diff --git a/ext/iodine/iodine_mustache.c b/ext/iodine/iodine_mustache.c
index c88a0b1..9df9470 100644
--- a/ext/iodine/iodine_mustache.c
+++ b/ext/iodine/iodine_mustache.c
@@ -558,7 +558,7 @@ void iodine_init_mustache(void) {
   rb_global_variable(&filename_id);
   rb_global_variable(&data_id);
   rb_global_variable(&template_id);
-  VALUE tmp = rb_define_class_under(IodineModule, "Mustache", rb_cData);
+  VALUE tmp = rb_define_class_under(IodineModule, "Mustache", rb_cObject);
   rb_define_alloc_func(tmp, iodine_mustache_data_alloc_c);
   rb_define_method(tmp, "initialize", iodine_mustache_new, -1);
   rb_define_method(tmp, "render", iodine_mustache_render, 1);
diff --git a/ext/iodine/iodine_store.c b/ext/iodine/iodine_store.c
index 05fa5f4..495e08f 100644
--- a/ext/iodine/iodine_store.c
+++ b/ext/iodine/iodine_store.c
@@ -132,7 +132,7 @@ struct IodineStorage_s IodineStore = {
 void iodine_storage_init(void) {
   fio_store_capa_require(&iodine_storage, 512);
   VALUE tmp =
-      rb_define_class_under(rb_cObject, "IodineObjectStorage", rb_cData);
+      rb_define_class_under(rb_cObject, "IodineObjectStorage", rb_cObject);
   VALUE storage_obj =
       TypedData_Wrap_Struct(tmp, &storage_type_struct, &iodine_storage);
   // rb_global_variable(&iodine_storage_obj);
diff --git a/ext/iodine/iodine_tls.c b/ext/iodine/iodine_tls.c
index 9d05d61..e296e7c 100644
--- a/ext/iodine/iodine_tls.c
+++ b/ext/iodine/iodine_tls.c
@@ -234,7 +234,7 @@ void iodine_init_tls(void) {
   IODINE_MAKE_SYM(private_key);
   IODINE_MAKE_SYM(password);
 
-  IodineTLSClass = rb_define_class_under(IodineModule, "TLS", rb_cData);
+  IodineTLSClass = rb_define_class_under(IodineModule, "TLS", rb_cObject);
   rb_define_alloc_func(IodineTLSClass, iodine_tls_data_alloc_c);
   rb_define_method(IodineTLSClass, "initialize", iodine_tls_new, -1);
   rb_define_method(IodineTLSClass, "use_certificate",
diff --git a/ext/iodine/websocket_deflate.h b/ext/iodine/websocket_deflate.h
new file mode 100644
index 0000000..fce6b44
--- /dev/null
+++ b/ext/iodine/websocket_deflate.h
@@ -0,0 +1,94 @@
+/*
+  copyright: Boaz Segev, 2017-2019
+  license: MIT
+
+  Feel free to copy, use and enjoy according to the license specified.
+*/
+#ifndef H_WEBSOCKET_DEFLATE_H
+/**\file
+
+   A single file WebSocket permessage-deflate wrapper
+
+*/
+#define H_WEBSOCKET_DEFLATE_H
+#include <fiobj.h>
+#include <stdlib.h>
+#include <zlib.h>
+
+#define WS_CHUNK 16384
+
+z_stream *new_z_stream() {
+  z_stream *strm = malloc(sizeof(*strm));
+
+  *strm = (z_stream){
+    .zalloc = Z_NULL,
+    .zfree = Z_NULL,
+    .opaque = Z_NULL,
+  };
+
+  return strm;
+}
+
+z_stream *new_deflator() {
+  z_stream *strm = new_z_stream();
+
+  int ret = deflateInit2(strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
+                         -MAX_WBITS, 4, Z_DEFAULT_STRATEGY);
+
+  return strm;
+}
+
+z_stream *new_inflator() {
+  z_stream *strm = new_z_stream();
+
+  inflateInit2(strm, -MAX_WBITS);
+
+  return strm;
+}
+
+int deflate_message(fio_str_info_s src, FIOBJ dest, z_stream *strm) {
+  int ret, flush;
+  unsigned have;
+  unsigned char out[WS_CHUNK];
+
+  strm->avail_in = src.len;
+  strm->next_in = src.data;
+
+  do {
+    strm->avail_out = WS_CHUNK;
+    strm->next_out = out;
+    ret = deflate(strm, Z_SYNC_FLUSH);
+    have = WS_CHUNK - strm->avail_out;
+    fiobj_str_write(dest, out, have);
+  } while (strm->avail_out == 0);
+
+  return Z_OK;
+}
+
+int inflate_message(fio_str_info_s src, FIOBJ dest, z_stream *strm) {
+  int ret;
+  unsigned have;
+  unsigned char out[WS_CHUNK];
+
+  strm->avail_in = src.len;
+  strm->next_in = src.data;
+
+  do {
+    strm->avail_out = WS_CHUNK;
+    strm->next_out = out;
+    ret = inflate(strm, Z_SYNC_FLUSH);
+    switch (ret) {
+    case Z_NEED_DICT:
+      ret = Z_DATA_ERROR;
+    case Z_DATA_ERROR:
+    case Z_MEM_ERROR:
+      (void)inflateEnd(strm);
+      return ret;
+    }
+    have = WS_CHUNK - strm->avail_out;
+    fiobj_str_write(dest, out, have);
+  } while (strm->avail_out == 0);
+
+  return ret;
+}
+#endif
diff --git a/ext/iodine/websockets.c b/ext/iodine/websockets.c
index 87353ef..8d93bbf 100644
--- a/ext/iodine/websockets.c
+++ b/ext/iodine/websockets.c
@@ -26,6 +26,8 @@ Feel free to copy, use and enjoy according to the license provided.
 
 #include <websocket_parser.h>
 
+#include <websocket_deflate.h>
+
 #if !defined(__BIG_ENDIAN__) && !defined(__LITTLE_ENDIAN__)
 #include <endian.h>
 #if !defined(__BIG_ENDIAN__) && !defined(__LITTLE_ENDIAN__) &&                 \
@@ -130,6 +132,10 @@ struct ws_s {
   uint8_t is_text;
   /** websocket connection type. */
   uint8_t is_client;
+
+  z_stream *inflator;
+  z_stream *deflator;
+  size_t deflate_min;
 };
 
 /* *****************************************************************************
@@ -152,7 +158,10 @@ static void websocket_on_unwrapped(void *ws_p, void *msg, uint64_t len,
                                    char first, char last, char text,
                                    unsigned char rsv) {
   ws_s *ws = ws_p;
-  if (last && first) {
+  static char ws_payload_tail[] = {0x00, 0x00, 0xFF, 0xFF};
+
+  // Shortcut only if not deflated
+  if (last && first && !(rsv & 4)) {
     ws->on_message(ws, (fio_str_info_s){.data = msg, .len = len},
                    (uint8_t)text);
     return;
@@ -165,7 +174,20 @@ static void websocket_on_unwrapped(void *ws_p, void *msg, uint64_t len,
   }
   fiobj_str_write(ws->msg, msg, len);
   if (last) {
-    ws->on_message(ws, fiobj_obj2cstr(ws->msg), ws->is_text);
+    if (rsv & 4) {
+      fiobj_str_write(ws->msg, ws_payload_tail, 4);
+      fio_str_info_s deflated = fiobj_obj2cstr(ws->msg);
+      FIOBJ inflated = fiobj_str_buf(deflated.len);
+
+      if (ws->inflator == NULL) {
+        ws->inflator = new_inflator();
+      }
+      int ret = inflate_message(deflated, inflated, ws->inflator);
+
+      ws->on_message(ws, fiobj_obj2cstr(inflated), ws->is_text);
+    } else {
+      ws->on_message(ws, fiobj_obj2cstr(ws->msg), ws->is_text);
+    }
   }
 
   (void)rsv;
@@ -296,7 +318,7 @@ static void on_data_first(intptr_t sockfd, fio_protocol_s *ws_) {
 
 /* later */
 static void websocket_write_impl(intptr_t fd, void *data, size_t len, char text,
-                                 char first, char last, char client);
+                                 char first, char last, char client, char rsv);
 
 /*******************************************************************************
 Create/Destroy the websocket object
@@ -305,6 +327,7 @@ Create/Destroy the websocket object
 static ws_s *new_websocket(intptr_t uuid) {
   // allocate the protocol object
   ws_s *ws = malloc(sizeof(*ws));
+
   *ws = (ws_s){
       .protocol.ping = ws_ping,
       .protocol.on_data = on_data_first,
@@ -314,6 +337,9 @@ static ws_s *new_websocket(intptr_t uuid) {
       .subscriptions = FIO_LS_INIT(ws->subscriptions),
       .is_client = 0,
       .fd = uuid,
+      .inflator = NULL,
+      .deflator = NULL,
+      .deflate_min = (size_t)-1,
   };
   return ws;
 }
@@ -330,6 +356,10 @@ static void destroy_ws(ws_s *ws) {
 void websocket_attach(intptr_t uuid, http_settings_s *http_settings,
                       websocket_settings_s *args, void *data, size_t length) {
   ws_s *ws = new_websocket(uuid);
+  if (http_settings->deflate && http_settings->deflate != -1) {
+    ws->deflator = new_deflator();
+    ws->deflate_min = http_settings->deflate;
+  }
   FIO_ASSERT_ALLOC(ws);
   // we have an active websocket connection - prep the connection buffer
   ws->buffer = create_ws_buffer(ws);
@@ -380,24 +410,30 @@ Writing to the Websocket
   (FIO_MEMORY_BLOCK_ALLOC_LIMIT - 4096) // should be less then `unsigned short`
 
 static void websocket_write_impl(intptr_t fd, void *data, size_t len, char text,
-                                 char first, char last, char client) {
+                                 char first, char last, char client, char rsv) {
   if (len <= WS_MAX_FRAME_SIZE) {
     void *buff = fio_malloc(len + 16);
     len = (client ? websocket_client_wrap(buff, data, len, (text ? 1 : 2),
-                                          first, last, 0)
+                                          first, last, rsv)
                   : websocket_server_wrap(buff, data, len, (text ? 1 : 2),
-                                          first, last, 0));
+                                          first, last, rsv));
     fio_write2(fd, .data.buffer = buff, .length = len,
                .after.dealloc = fio_free);
   } else {
+    int firstFrame = 1;
     /* frame fragmentation is better for large data then large frames */
     while (len > WS_MAX_FRAME_SIZE) {
-      websocket_write_impl(fd, data, WS_MAX_FRAME_SIZE, text, first, 0, client);
+      websocket_write_impl(fd, data, WS_MAX_FRAME_SIZE, text, first, 0, client, rsv);
+      if (firstFrame) {
+        firstFrame = 0;
+        // should only set compressed flag on first frame
+        rsv &= 3;
+      }
       data = ((uint8_t *)data) + WS_MAX_FRAME_SIZE;
       first = 0;
       len -= WS_MAX_FRAME_SIZE;
     }
-    websocket_write_impl(fd, data, len, text, first, 1, client);
+    websocket_write_impl(fd, data, len, text, first, 1, client, rsv);
   }
   return;
 }
@@ -715,9 +751,22 @@ uint8_t websocket_is_client(ws_s *ws) { return ws->is_client; }
 
 /** Writes data to the websocket. Returns -1 on failure (0 on success). */
 int websocket_write(ws_s *ws, fio_str_info_s msg, uint8_t is_text) {
+  char rsv = 0;
+  if (msg.len >= ws->deflate_min && is_text == 1) {
+    rsv |= 4;
+  }
+
+  if (rsv & 4) {
+    size_t orig_len = msg.len;
+    FIOBJ deflated = fiobj_str_buf(msg.len);
+    deflate_message(msg, deflated, ws->deflator);
+    msg = fiobj_obj2cstr(deflated);
+    msg.len -= 4;
+  }
+
   if (fio_is_valid(ws->fd)) {
     websocket_write_impl(ws->fd, msg.data, msg.len, is_text, 1, 1,
-                         ws->is_client);
+                         ws->is_client, rsv);
     return 0;
   }
   return -1;
diff --git a/iodine.gemspec b/iodine.gemspec
index 5eaadd1..2114459 100644
--- a/iodine.gemspec
+++ b/iodine.gemspec
@@ -38,7 +38,7 @@ Gem::Specification.new do |spec|
   spec.requirements << 'TLS requires OpenSSL >= 1.1.0'
 
   # spec.add_development_dependency 'bundler', '>= 1.10', '< 2.0'
-  spec.add_development_dependency 'rake', '~> 12.0', '< 13.0'
+  spec.add_development_dependency 'rake', '~> 13.0'
   spec.add_development_dependency 'minitest', '>=5', '< 6.0'
   spec.add_development_dependency 'rspec', '>=3.9.0', '< 4.0'
   spec.add_development_dependency 'spec', '>=5.3.0', '< 6.0'