diff --git a/net/http/test/CMakeLists.txt b/net/http/test/CMakeLists.txt
index 62d10242e72b2..ea6467e650b2f 100644
--- a/net/http/test/CMakeLists.txt
+++ b/net/http/test/CMakeLists.txt
@@ -5,14 +5,37 @@
 # For the list of contributors see $ROOTSYS/README/CREDITS.
 
 ############################################################################
-# CMakeLists.txt file for building ROOT net/http package
+# CMakeLists.txt file for building ROOT net/http/test package
 # @author Sergey Linev, GSI
 ############################################################################
 
+# http server does not work on Windows without extra firewall configuration
+if(WIN32)
+  return()
+endif()
+
+# curl is required for tests
 find_program(CURL_EXECUTABLE curl)
 
-# http server does not work on default Windows configuration
-# so skip testing there
-if(CURL_EXECUTABLE AND NOT WIN32)
-  ROOT_ADD_GTEST(testHttpServer test_server.cxx LIBRARIES RHTTP RHTTPSniff Hist)
+if(NOT CURL_EXECUTABLE)
+  return()
+endif()
+
+ROOT_ADD_GTEST(testHttpServer test_server.cxx LIBRARIES RHTTP RHTTPSniff Hist)
+
+execute_process(
+    COMMAND "${CURL_EXECUTABLE}" --version
+    OUTPUT_VARIABLE CURL_CLI_OUTPUT
+    ERROR_QUIET
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+)
+
+# only newer curl support websockets - so test version
+# curl introduce support from 8.11 but it works reliably only with 8.18
+if(CURL_CLI_OUTPUT MATCHES "curl ([0-9]+\\.[0-9]+\\.[0-9]+)")
+  set(CURL_CLI_VERSION "${CMAKE_MATCH_1}")
+  message(STATUS "Find curl ${CURL_CLI_VERSION} for http server tests")
+  if(CURL_CLI_VERSION VERSION_GREATER_EQUAL "8.18.0")
+    ROOT_ADD_GTEST(testWebSocket test_websocket.cxx LIBRARIES RHTTP Hist)
+  endif()
 endif()
diff --git a/net/http/test/test_server.cxx b/net/http/test/test_server.cxx
index daf88ddb60803..a4a5404462124 100644
--- a/net/http/test/test_server.cxx
+++ b/net/http/test/test_server.cxx
@@ -15,6 +15,7 @@
 Int_t httpport = 0;
 TString server_url;
 
+
 // main http server
 std::string execute_request(const char *url, const char *post = nullptr)
 {
@@ -25,10 +26,12 @@ std::string execute_request(const char *url, const char *post = nullptr)
       pname = TString::Format("http_server_%d.post", httpport);
       std::ofstream f(pname.Data());
       f << post;
+   }
+
+   if (post)
       exec = TString::Format("curl -sS -X POST '%s%s' --data-binary @%s -o %s", server_url.Data(), url, pname.Data(), fname.Data());
-   } else {
+   else
       exec = TString::Format("curl -sS '%s%s' -o %s", server_url.Data(), url, fname.Data());
-   }
 
    printf("Execute %s\n", exec.Data());
 
@@ -56,7 +59,7 @@ TEST(THttpServer, main)
    for(int ntry = 0; ntry < 100; ++ntry) {
       Int_t port = (Int_t) (25000 + gRandom->Rndm() * 1000);
       // only two threads, bind to loopback address only
-      TString arg = TString::Format("http:%d?loopback&thrds=2", port);
+      TString arg = TString::Format("http:%d?loopback&thrds=3", port);
       if (serv.CreateEngine(arg)) {
          httpport = port;
          break;
diff --git a/net/http/test/test_websocket.cxx b/net/http/test/test_websocket.cxx
new file mode 100644
index 0000000000000..0b34e9a473406
--- /dev/null
+++ b/net/http/test/test_websocket.cxx
@@ -0,0 +1,140 @@
+#include "gtest/gtest.h"
+
+#include <string>
+#include <fstream>
+
+#include "THttpServer.h"
+#include "THttpWSHandler.h"
+#include "TROOT.h"
+
+#include "TSystem.h"
+#include "TRandom.h"
+
+#include "ROOT/TestSupport.hxx"
+
+Int_t httpport = 0;
+TString server_url;
+
+class TUserHandler : public THttpWSHandler {
+   public:
+      UInt_t fWSId{0};
+      Int_t fServCnt{0};
+
+      TUserHandler(const char *name = nullptr, const char *title = nullptr) : THttpWSHandler(name, title) {}
+
+      // load custom HTML page when open correspondent address
+      TString GetDefaultPageContent() override { return "dummy_page_content"; }
+
+      // ignore threads safety - allow multi-threaded use of handler
+      Bool_t AllowMTProcess() const override { return kFALSE; }
+
+      Bool_t ProcessWS(THttpCallArg *arg) override
+      {
+         if (!arg || (arg->GetWSId() == 0))
+            return kTRUE;
+
+         if (arg->IsMethod("WS_CONNECT")) {
+            // accept only if connection not established
+            return fWSId == 0;
+         }
+
+         if (arg->IsMethod("WS_READY")) {
+            fWSId = arg->GetWSId();
+            return kTRUE;
+         }
+
+         if (arg->IsMethod("WS_CLOSE")) {
+            fWSId = 0;
+            return kTRUE;
+         }
+
+         if (arg->IsMethod("WS_DATA")) {
+            TString str;
+            str.Append((const char *)arg->GetPostData(), arg->GetPostDataLength());
+            if ((str == "DataRequest") && (arg->GetWSId() == fWSId))
+               SendCharStarWS(arg->GetWSId(), "DataResponse");
+            else
+               SendCharStarWS(arg->GetWSId(), "DataRejected");
+            return kTRUE;
+         }
+
+         return kFALSE;
+      }
+};
+
+
+// main http server
+std::string execute_request(const char *url, const char *post = nullptr, Bool_t ws = kFALSE)
+{
+   TString fname = TString::Format("http_server_%d.output", httpport),
+           pname, exec;
+
+   if (post) {
+      pname = TString::Format("http_server_%d.post", httpport);
+      std::ofstream f(pname.Data());
+      f << post;
+   }
+
+   if (post && ws)
+      exec = TString::Format("curl --no-progress-meter --max-time 10 -T . -N ws://localhost:%d%s < %s > %s", httpport, url, pname.Data(), fname.Data());
+   else if (post)
+      exec = TString::Format("curl --no-progress-meter -X POST '%s%s' --data-binary @%s -o %s", server_url.Data(), url, pname.Data(), fname.Data());
+   else
+      exec = TString::Format("curl --no-progress-meter '%s%s' -o %s", server_url.Data(), url, fname.Data());
+
+   printf("Execute %s\n", exec.Data());
+
+   std::string res;
+
+   // websocket ends with timeout - ignore failure for it
+   if ((gSystem->Exec(exec) != 0) && !ws)
+      res = "<fail>";
+   else
+      res = THttpServer::ReadFileContent(fname.Data());
+
+   gSystem->Unlink(fname);
+   if (!pname.IsNull())
+      gSystem->Unlink(pname);
+
+   return res;
+}
+
+// main http server
+TEST(THttpServer, main)
+{
+   THttpServer serv("");
+
+   gRandom->SetSeed(0);
+
+   for(int ntry = 0; ntry < 100; ++ntry) {
+      Int_t port = (Int_t) (25000 + gRandom->Rndm() * 1000);
+      // only two threads, bind to loopback address only
+      TString arg = TString::Format("http:%d?loopback&thrds=3", port);
+      if (serv.CreateEngine(arg)) {
+         httpport = port;
+         break;
+      }
+   }
+
+   EXPECT_NE(httpport, 0);
+
+   if (!httpport)
+      return;
+
+   server_url = TString::Format("http:/localhost:%d", httpport);
+
+   TUserHandler handler("ws", "Test WebSocket handler");
+
+   serv.Register("/", &handler);
+
+   // let process requests in separate thread
+   serv.CreateServerThread();
+
+   // test reply on html page request
+   std::string res = execute_request("/ws/index.htm");
+   EXPECT_EQ(res, "dummy_page_content") << "default html page for webcosket handler";
+
+   // test reply on websocket request
+   res = execute_request("/ws/root.websocket", "DataRequest", kTRUE);
+   EXPECT_EQ(res, "DataResponse") << "check data after websocket communication";
+}