--- a/devtools/client/locales/en-US/netmonitor.properties
+++ b/devtools/client/locales/en-US/netmonitor.properties
@@ -619,16 +619,24 @@ netmonitor.toolbar.filter.other=Other
 # LOCALIZATION NOTE (netmonitor.toolbar.filterFreetext.label): This is the label
 # displayed in the network toolbar for the url filtering textbox.
 netmonitor.toolbar.filterFreetext.label=Filter URLs
 
 # LOCALIZATION NOTE (netmonitor.toolbar.filterFreetext.key): This is the
 # shortcut key to focus on the toolbar url filtering textbox
 netmonitor.toolbar.filterFreetext.key=CmdOrCtrl+F
 
+# LOCALIZATION NOTE (netmonitor.toolbar.disableCache.label): This is the label
+# displayed for the checkbox for disabling browser cache.
+netmonitor.toolbar.disableCache.label=Disable cache
+
+# LOCALIZATION NOTE (netmonitor.toolbar.disableCache.tooltip): This is the tooltip
+# displayed for the checkbox for disabling browser cache.
+netmonitor.toolbar.disableCache.tooltip=Disable HTTP cache
+
 # LOCALIZATION NOTE (netmonitor.toolbar.clear): This is the label displayed
 # in the network toolbar for the "Clear" button.
 netmonitor.toolbar.clear=Clear
 
 # LOCALIZATION NOTE (netmonitor.toolbar.perf): This is the label displayed
 # in the network toolbar for the performance analysis button.
 netmonitor.toolbar.perf=Toggle performance analysis…
 

--- a/devtools/client/netmonitor/src/actions/ui.js
+++ b/devtools/client/netmonitor/src/actions/ui.js
@@ -2,16 +2,17 @@
  * 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 {
   ACTIVITY_TYPE,
   OPEN_NETWORK_DETAILS,
+  DISABLE_BROWSER_CACHE,
   OPEN_STATISTICS,
   RESET_COLUMNS,
   SELECT_DETAILS_PANEL_TAB,
   TOGGLE_COLUMN,
   WATERFALL_RESIZE,
 } = require("../constants");
 const { triggerActivity } = require("../connector/index");
 
@@ -23,16 +24,28 @@ const { triggerActivity } = require("../
 function openNetworkDetails(open) {
   return {
     type: OPEN_NETWORK_DETAILS,
     open,
   };
 }
 
 /**
+ * Change browser cache state.
+ *
+ * @param {boolean} disabled - expected browser cache in disable state
+ */
+function disableBrowserCache(disabled) {
+  return {
+    type: DISABLE_BROWSER_CACHE,
+    disabled,
+  };
+}
+
+/**
  * Change performance statistics panel open state.
  *
  * @param {boolean} visible - expected performance statistics panel open state
  */
 function openStatistics(open) {
   if (open) {
     triggerActivity(ACTIVITY_TYPE.RELOAD.WITH_CACHE_ENABLED);
   }
@@ -90,25 +103,35 @@ function toggleColumn(column) {
  * Toggle network details panel.
  */
 function toggleNetworkDetails() {
   return (dispatch, getState) =>
     dispatch(openNetworkDetails(!getState().ui.networkDetailsOpen));
 }
 
 /**
+ * Toggle browser cache status.
+ */
+function toggleBrowserCache() {
+  return (dispatch, getState) =>
+    dispatch(disableBrowserCache(!getState().ui.browserCacheDisabled));
+}
+
+/**
  * Toggle performance statistics panel.
  */
 function toggleStatistics() {
   return (dispatch, getState) =>
     dispatch(openStatistics(!getState().ui.statisticsOpen));
 }
 
 module.exports = {
   openNetworkDetails,
+  disableBrowserCache,
   openStatistics,
   resetColumns,
   resizeWaterfall,
   selectDetailsPanelTab,
   toggleColumn,
   toggleNetworkDetails,
+  toggleBrowserCache,
   toggleStatistics,
 };

--- a/devtools/client/netmonitor/src/assets/styles/netmonitor.css
+++ b/devtools/client/netmonitor/src/assets/styles/netmonitor.css
@@ -782,16 +782,27 @@ body,
 .properties-view .devtools-searchbox {
   padding: 0;
 }
 
 .properties-view .devtools-searchbox input {
   margin: 1px 3px;
 }
 
+.devtools-checkbox {
+  position: relative;
+  vertical-align: middle;
+  bottom: 1px;
+}
+
+.devtools-checkbox-label {
+  margin-inline-start: 10px;
+  margin-inline-end: 3px;
+}
+
 /* Empty notices in tab panels */
 
 .empty-notice {
   color: var(--theme-body-color-alt);
   padding: 3px 8px;
 }
 
 /* Text inputs in tab panels */

--- a/devtools/client/netmonitor/src/components/toolbar.js
+++ b/devtools/client/netmonitor/src/components/toolbar.js
@@ -1,14 +1,15 @@
 /* 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 {
   createClass,
   createFactory,
   DOM,
   PropTypes,
 } = require("devtools/client/shared/vendor/react");
 const { connect } = require("devtools/client/shared/vendor/react-redux");
 const Actions = require("../actions/index");
@@ -20,38 +21,43 @@ const {
 } = require("../selectors/index");
 
 const { autocompleteProvider } = require("../utils/filter-text-utils");
 const { L10N } = require("../utils/l10n");
 
 // Components
 const SearchBox = createFactory(require("devtools/client/shared/components/search-box"));
 
-const { button, div, span } = DOM;
+const { button, div, input, label, span } = DOM;
 
 const COLLPASE_DETAILS_PANE = L10N.getStr("collapseDetailsPane");
 const EXPAND_DETAILS_PANE = L10N.getStr("expandDetailsPane");
 const SEARCH_KEY_SHORTCUT = L10N.getStr("netmonitor.toolbar.filterFreetext.key");
 const SEARCH_PLACE_HOLDER = L10N.getStr("netmonitor.toolbar.filterFreetext.label");
 const TOOLBAR_CLEAR = L10N.getStr("netmonitor.toolbar.clear");
 
+const DEVTOOLS_DISABLE_CACHE_PREF = "devtools.cache.disabled";
+
 /*
  * Network monitor toolbar component
  * Toolbar contains a set of useful tools to control network requests
  */
 const Toolbar = createClass({
   displayName: "Toolbar",
 
   propTypes: {
     clearRequests: PropTypes.func.isRequired,
     requestFilterTypes: PropTypes.array.isRequired,
     setRequestFilterText: PropTypes.func.isRequired,
     networkDetailsToggleDisabled: PropTypes.bool.isRequired,
     networkDetailsOpen: PropTypes.bool.isRequired,
     toggleNetworkDetails: PropTypes.func.isRequired,
+    disableBrowserCache: PropTypes.func.isRequired,
+    toggleBrowserCache: PropTypes.func.isRequired,
+    browserCacheDisabled: PropTypes.bool.isRequired,
     toggleRequestFilterType: PropTypes.func.isRequired,
   },
 
   toggleRequestFilterType(evt) {
     if (evt.type === "keydown" && (evt.key !== "" || evt.key !== "Enter")) {
       return;
     }
     this.props.toggleRequestFilterType(evt.target.dataset.key);
@@ -60,16 +66,18 @@ const Toolbar = createClass({
   render() {
     let {
       clearRequests,
       requestFilterTypes,
       setRequestFilterText,
       networkDetailsToggleDisabled,
       networkDetailsOpen,
       toggleNetworkDetails,
+      toggleBrowserCache,
+      browserCacheDisabled,
     } = this.props;
 
     let toggleButtonClassName = [
       "network-details-panel-toggle",
       "devtools-button",
     ];
     if (!networkDetailsOpen) {
       toggleButtonClassName.push("pane-collapsed");
@@ -97,16 +105,30 @@ const Toolbar = createClass({
       span({ className: "devtools-toolbar devtools-toolbar-container" },
         span({ className: "devtools-toolbar-group" },
           button({
             className: "devtools-button devtools-clear-icon requests-list-clear-button",
             title: TOOLBAR_CLEAR,
             onClick: clearRequests,
           }),
           div({ className: "requests-list-filter-buttons" }, buttons),
+          label(
+            {
+              className: "devtools-checkbox-label",
+              title: L10N.getStr("netmonitor.toolbar.disableCache.tooltip"),
+            },
+            input({
+              id: "devtools-cache-checkbox",
+              className: "devtools-checkbox",
+              type: "checkbox",
+              checked: browserCacheDisabled,
+              onClick: toggleBrowserCache,
+            }),
+            L10N.getStr("netmonitor.toolbar.disableCache.label"),
+          ),
         ),
         span({ className: "devtools-toolbar-group" },
           SearchBox({
             delay: FILTER_SEARCH_DELAY,
             keyShortcut: SEARCH_KEY_SHORTCUT,
             placeholder: SEARCH_PLACE_HOLDER,
             type: "filter",
             onChange: setRequestFilterText,
@@ -117,25 +139,43 @@ const Toolbar = createClass({
             title: networkDetailsOpen ? COLLPASE_DETAILS_PANE : EXPAND_DETAILS_PANE,
             disabled: networkDetailsToggleDisabled,
             tabIndex: "0",
             onClick: toggleNetworkDetails,
           }),
         )
       )
     );
+  },
+
+  componentDidMount() {
+    Services.prefs.addObserver(DEVTOOLS_DISABLE_CACHE_PREF,
+                               this.updateBrowserCacheDisabled);
+  },
+
+  componentWillUnmount() {
+    Services.prefs.removeObserver(DEVTOOLS_DISABLE_CACHE_PREF,
+                                  this.updateBrowserCacheDisabled);
+  },
+
+  updateBrowserCacheDisabled() {
+    this.props.disableBrowserCache(
+                        Services.prefs.getBoolPref(DEVTOOLS_DISABLE_CACHE_PREF));
   }
 });
 
 module.exports = connect(
   (state) => ({
     networkDetailsToggleDisabled: isNetworkDetailsToggleButtonDisabled(state),
     networkDetailsOpen: state.ui.networkDetailsOpen,
+    browserCacheDisabled: state.ui.browserCacheDisabled,
     requestFilterTypes: getRequestFilterTypes(state),
     summary: getDisplayedRequestsSummary(state),
   }),
   (dispatch) => ({
     clearRequests: () => dispatch(Actions.clearRequests()),
     setRequestFilterText: (text) => dispatch(Actions.setRequestFilterText(text)),
     toggleRequestFilterType: (type) => dispatch(Actions.toggleRequestFilterType(type)),
     toggleNetworkDetails: () => dispatch(Actions.toggleNetworkDetails()),
+    disableBrowserCache: (disabled) => dispatch(Actions.disableBrowserCache(disabled)),
+    toggleBrowserCache: () => dispatch(Actions.toggleBrowserCache()),
   }),
 )(Toolbar);

--- a/devtools/client/netmonitor/src/constants.js
+++ b/devtools/client/netmonitor/src/constants.js
@@ -9,16 +9,17 @@ const actionTypes = {
   ADD_TIMING_MARKER: "ADD_TIMING_MARKER",
   BATCH_ACTIONS: "BATCH_ACTIONS",
   BATCH_ENABLE: "BATCH_ENABLE",
   CLEAR_REQUESTS: "CLEAR_REQUESTS",
   CLEAR_TIMING_MARKERS: "CLEAR_TIMING_MARKERS",
   CLONE_SELECTED_REQUEST: "CLONE_SELECTED_REQUEST",
   ENABLE_REQUEST_FILTER_TYPE_ONLY: "ENABLE_REQUEST_FILTER_TYPE_ONLY",
   OPEN_NETWORK_DETAILS: "OPEN_NETWORK_DETAILS",
+  DISABLE_BROWSER_CACHE: "DISABLE_BROWSER_CACHE",
   OPEN_STATISTICS: "OPEN_STATISTICS",
   REMOVE_SELECTED_CUSTOM_REQUEST: "REMOVE_SELECTED_CUSTOM_REQUEST",
   RESET_COLUMNS: "RESET_COLUMNS",
   SELECT_REQUEST: "SELECT_REQUEST",
   SELECT_DETAILS_PANEL_TAB: "SELECT_DETAILS_PANEL_TAB",
   SEND_CUSTOM_REQUEST: "SEND_CUSTOM_REQUEST",
   SET_REQUEST_FILTER_TEXT: "SET_REQUEST_FILTER_TEXT",
   SORT_BY: "SORT_BY",

--- a/devtools/client/netmonitor/src/middleware/prefs.js
+++ b/devtools/client/netmonitor/src/middleware/prefs.js
@@ -5,16 +5,17 @@
 "use strict";
 
 const Services = require("Services");
 const {
   ENABLE_REQUEST_FILTER_TYPE_ONLY,
   RESET_COLUMNS,
   TOGGLE_COLUMN,
   TOGGLE_REQUEST_FILTER_TYPE,
+  DISABLE_BROWSER_CACHE,
 } = require("../constants");
 const { getRequestFilterTypes } = require("../selectors/index");
 
 /**
   * Update the relevant prefs when:
   *   - a column has been toggled
   *   - a filter type has been set
   */
@@ -25,16 +26,20 @@ function prefsMiddleware(store) {
       case ENABLE_REQUEST_FILTER_TYPE_ONLY:
       case TOGGLE_REQUEST_FILTER_TYPE:
         let filters = getRequestFilterTypes(store.getState())
           .filter(([type, check]) => check)
           .map(([type, check]) => type);
         Services.prefs.setCharPref(
           "devtools.netmonitor.filters", JSON.stringify(filters));
         break;
+      case DISABLE_BROWSER_CACHE:
+        Services.prefs.setBoolPref(
+          "devtools.cache.disabled", store.getState().ui.browserCacheDisabled);
+        break;
       case TOGGLE_COLUMN:
       case RESET_COLUMNS:
         let visibleColumns = [...store.getState().ui.columns]
           .filter(([column, shown]) => shown)
           .map(([column, shown]) => column);
         Services.prefs.setCharPref(
           "devtools.netmonitor.visibleColumns", JSON.stringify(visibleColumns));
         break;

--- a/devtools/client/netmonitor/src/reducers/ui.js
+++ b/devtools/client/netmonitor/src/reducers/ui.js
@@ -1,18 +1,20 @@
 /* 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 I = require("devtools/client/shared/vendor/immutable");
+const Services = require("Services");
 const {
   CLEAR_REQUESTS,
   OPEN_NETWORK_DETAILS,
+  DISABLE_BROWSER_CACHE,
   OPEN_STATISTICS,
   REMOVE_SELECTED_CUSTOM_REQUEST,
   RESET_COLUMNS,
   RESPONSE_HEADERS,
   SELECT_DETAILS_PANEL_TAB,
   SEND_CUSTOM_REQUEST,
   SELECT_REQUEST,
   TOGGLE_COLUMN,
@@ -46,32 +48,37 @@ const Columns = I.Record(
     RESPONSE_HEADERS.reduce((acc, header) => Object.assign(acc, { [header]: false }), {})
   )
 );
 
 const UI = I.Record({
   columns: new Columns(),
   detailsPanelSelectedTab: "headers",
   networkDetailsOpen: false,
+  browserCacheDisabled: Services.prefs.getBoolPref("devtools.cache.disabled"),
   statisticsOpen: false,
   waterfallWidth: null,
 });
 
 function resetColumns(state) {
   return state.set("columns", new Columns());
 }
 
 function resizeWaterfall(state, action) {
   return state.set("waterfallWidth", action.width);
 }
 
 function openNetworkDetails(state, action) {
   return state.set("networkDetailsOpen", action.open);
 }
 
+function disableBrowserCache(state, action) {
+  return state.set("browserCacheDisabled", action.disabled);
+}
+
 function openStatistics(state, action) {
   return state.set("statisticsOpen", action.open);
 }
 
 function setDetailsPanelTab(state, action) {
   return state.set("detailsPanelSelectedTab", action.id);
 }
 
@@ -89,16 +96,18 @@ function toggleColumn(state, action) {
 }
 
 function ui(state = new UI(), action) {
   switch (action.type) {
     case CLEAR_REQUESTS:
       return openNetworkDetails(state, { open: false });
     case OPEN_NETWORK_DETAILS:
       return openNetworkDetails(state, action);
+    case DISABLE_BROWSER_CACHE:
+      return disableBrowserCache(state, action);
     case OPEN_STATISTICS:
       return openStatistics(state, action);
     case RESET_COLUMNS:
       return resetColumns(state);
     case REMOVE_SELECTED_CUSTOM_REQUEST:
     case SEND_CUSTOM_REQUEST:
       return openNetworkDetails(state, { open: false });
     case SELECT_DETAILS_PANEL_TAB: