diff --git a/devtools/client/netmonitor/src/request-list-context-menu.js b/devtools/client/netmonitor/src/request-list-context-menu.js
index 99bdf3ace781..4dbf133d1131 100644
--- a/devtools/client/netmonitor/src/request-list-context-menu.js
+++ b/devtools/client/netmonitor/src/request-list-context-menu.js
@@ -11,6 +11,7 @@ const { saveAs } = require("devtools/client/shared/file-saver");
 const { copyString } = require("devtools/shared/platform/clipboard");
 const { showMenu } = require("devtools/client/netmonitor/src/utils/menu");
 const { HarExporter } = require("./har/har-exporter");
+const { openRequestInTab } = require("devtools/client/netmonitor/src/utils/firefox/open-request-in-tab");
 const {
   getSelectedRequest,
   getSortedRequests,
@@ -182,7 +183,7 @@ class RequestListContextMenu {
       label: L10N.getStr("netmonitor.context.newTab"),
       accesskey: L10N.getStr("netmonitor.context.newTab.accesskey"),
       visible: !!selectedRequest,
-      click: () => this.openRequestInTab(url),
+      click: () => this.openRequestInTab(selectedRequest),
     });
 
     menu.push({
@@ -217,9 +218,8 @@ class RequestListContextMenu {
   /**
    * Opens selected item in a new tab.
    */
-  openRequestInTab(url) {
-    let win = Services.wm.getMostRecentWindow(gDevTools.chromeWindowType);
-    win.openUILinkIn(url, "tab", { relatedToCurrent: true });
+  openRequestInTab(selectedRequest) {
+    openRequestInTab(selectedRequest);
   }
 
   /**
diff --git a/devtools/client/netmonitor/src/utils/firefox/moz.build b/devtools/client/netmonitor/src/utils/firefox/moz.build
new file mode 100644
index 000000000000..56ad27a435e7
--- /dev/null
+++ b/devtools/client/netmonitor/src/utils/firefox/moz.build
@@ -0,0 +1,8 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DevToolsModules(
+    'open-request-in-tab.js',
+)
diff --git a/devtools/client/netmonitor/src/utils/firefox/open-request-in-tab.js b/devtools/client/netmonitor/src/utils/firefox/open-request-in-tab.js
new file mode 100644
index 000000000000..80f52c6f74c6
--- /dev/null
+++ b/devtools/client/netmonitor/src/utils/firefox/open-request-in-tab.js
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+/* eslint-disable mozilla/reject-some-requires */
+
+"use strict";
+
+let { Cc, Ci } = require("chrome");
+const Services = require("Services");
+const { gDevTools } = require("devtools/client/framework/devtools");
+
+/**
+ * Opens given request in a new tab.
+ */
+function openRequestInTab(request) {
+  let win = Services.wm.getMostRecentWindow(gDevTools.chromeWindowType);
+  let rawData = request.requestPostData ? request.requestPostData.postData : null;
+  let postData;
+
+  if (rawData && rawData.text) {
+    let stringStream = getInputStreamFromString(rawData.text);
+    postData = Cc["@mozilla.org/network/mime-input-stream;1"]
+      .createInstance(Ci.nsIMIMEInputStream);
+    postData.addHeader("Content-Type", "application/x-www-form-urlencoded");
+    postData.setData(stringStream);
+  }
+
+  win.gBrowser.selectedTab = win.gBrowser.addTab(request.url, null, null, postData);
+}
+
+function getInputStreamFromString(data) {
+  let stringStream = Cc["@mozilla.org/io/string-input-stream;1"]
+    .createInstance(Ci.nsIStringInputStream);
+  stringStream.data = data;
+  return stringStream;
+}
+
+module.exports = {
+  openRequestInTab,
+};
diff --git a/devtools/client/netmonitor/src/utils/moz.build b/devtools/client/netmonitor/src/utils/moz.build
index 3e7cabd87d14..208ca2823323 100644
--- a/devtools/client/netmonitor/src/utils/moz.build
+++ b/devtools/client/netmonitor/src/utils/moz.build
@@ -3,6 +3,10 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+DIRS += [
+    'firefox',
+]
+
 DevToolsModules(
     'create-store.js',
     'filter-autocomplete-provider.js',
@@ -12,6 +16,7 @@ DevToolsModules(
     'l10n.js',
     'mdn-utils.js',
     'menu.js',
+    'open-request-in-tab.js',
     'prefs.js',
     'request-utils.js',
     'sort-predicates.js',
diff --git a/devtools/client/netmonitor/src/utils/open-request-in-tab.js b/devtools/client/netmonitor/src/utils/open-request-in-tab.js
new file mode 100644
index 000000000000..3004241ffcdb
--- /dev/null
+++ b/devtools/client/netmonitor/src/utils/open-request-in-tab.js
@@ -0,0 +1,51 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const Services = require("Services");
+const { gDevTools } = require("devtools/client/framework/devtools");
+
+/**
+ * Opens given request in a new tab.
+ */
+function openRequestInTab(request) {
+  let win = Services.wm.getMostRecentWindow(gDevTools.chromeWindowType);
+  if (request.method.toLowerCase() !== "get") {
+    win.openUILinkIn(this.selectedRequest.url, "tab", {
+      relatedToCurrent: true
+    });
+  } else {
+    openRequestInTabHelper({
+      url: request.url,
+      method: request.method,
+      data: request.requestPostData ? request.requestPostData.postData : null,
+    });
+  }
+}
+
+function openRequestInTabHelper({url, method, data}) {
+  let form = document.createElement("form");
+  form.target = "_blank";
+  form.action = url;
+  form.method = method;
+
+  if (data) {
+    for (let key in data) {
+      let input = document.createElement("input");
+      input.name = key;
+      input.value = data[key];
+      form.appendChild(input);
+    }
+  }
+
+  form.hidden = true;
+  document.body.appendChild(form);
+  form.submit();
+  form.remove();
+}
+
+module.exports = {
+  openRequestInTab,
+};
diff --git a/devtools/client/netmonitor/webpack.config.js b/devtools/client/netmonitor/webpack.config.js
index 36dcb6ec1525..4a6625c32e79 100644
--- a/devtools/client/netmonitor/webpack.config.js
+++ b/devtools/client/netmonitor/webpack.config.js
@@ -86,6 +86,7 @@ let webpackConfig = {
       "devtools/shared/old-event-emitter": "devtools-modules/src/utils/event-emitter",
       "devtools/shared/fronts/timeline": path.join(__dirname, "../../client/shared/webpack/shims/fronts-timeline-shim"),
       "devtools/shared/platform/clipboard": path.join(__dirname, "../../client/shared/webpack/shims/platform-clipboard-stub"),
+      "devtools/client/netmonitor/src/utils/firefox/open-request-in-tab": path.join(__dirname, "src/utils/open-request-in-tab"),
 
       // Locales need to be explicitly mapped to the en-US subfolder
       "devtools/client/locales": path.join(__dirname, "../../client/locales/en-US"),