diff --git a/addons/base_import/static/src/xml/base_import.xml b/addons/base_import/static/src/xml/base_import.xml
index 951002b279f..c475a30036d 100644
--- a/addons/base_import/static/src/xml/base_import.xml
+++ b/addons/base_import/static/src/xml/base_import.xml
@@ -3,8 +3,6 @@
         <t t-set="_id" t-value="_.uniqueId('export')"/>
         <form action="" method="post" enctype="multipart/form-data" class="oe_import">
             <input type="hidden" name="csrf_token" t-att-value="csrf_token"/>
-            <input type="hidden" name="session_id"
-               t-att-value="widget.session.session_id"/>
             <input type="hidden" name="import_id"/>
             <div class="oe_import_box col-lg-12 d-none">
                 <input accept=".csv, .xls, .xlsx, .xlsm, .ods" t-attf-id="file_#{_id}"
diff --git a/addons/bus/controllers/main.py b/addons/bus/controllers/main.py
index a5a0e3e189b..6ff4d7ac8e0 100644
--- a/addons/bus/controllers/main.py
+++ b/addons/bus/controllers/main.py
@@ -27,7 +27,7 @@ class BusController(Controller):
         request._cr = None
         return dispatch.poll(dbname, channels, last, options)
 
-    @route('/longpolling/poll', type="json", auth="public")
+    @route('/longpolling/poll', type="json", auth="public", cors="*")
     def poll(self, channels, last, options=None):
         if options is None:
             options = {}
diff --git a/addons/im_livechat/controllers/main.py b/addons/im_livechat/controllers/main.py
index 86553625f4d..b3783d2f59d 100644
--- a/addons/im_livechat/controllers/main.py
+++ b/addons/im_livechat/controllers/main.py
@@ -3,13 +3,16 @@
 
 import base64
 
-from odoo import http, _
+from odoo import http,tools, _
 from odoo.http import request
 from odoo.addons.base.models.assetsbundle import AssetsBundle
 
 
 class LivechatController(http.Controller):
 
+    # Note: the `cors` attribute on many routes is meant to allow the livechat
+    # to be embedded in an external website.
+
     @http.route('/im_livechat/external_lib.<any(css,js):ext>', type='http', auth='none')
     def livechat_lib(self, ext, **kwargs):
         # _get_asset return the bundle html code (script and link list) but we want to use the attachment content
@@ -26,6 +29,17 @@ class LivechatController(http.Controller):
         headers.append(('Content-Length', len(content_base64)))
         return request.make_response(content_base64, headers)
 
+    @http.route('/im_livechat/load_templates', type='json', auth='none', cors="*")
+    def load_templates(self, **kwargs):
+        base_url = request.httprequest.base_url
+        templates = [
+            'mail/static/src/xml/abstract_thread_window.xml',
+            'mail/static/src/xml/discuss.xml',
+            'mail/static/src/xml/thread.xml',
+            'im_livechat/static/src/xml/im_livechat.xml',
+        ]
+        return [tools.file_open(tmpl, 'rb').read() for tmpl in templates]
+
     @http.route('/im_livechat/support/<int:channel_id>', type='http', auth='public')
     def support_page(self, channel_id, **kwargs):
         channel = request.env['im_livechat.channel'].sudo().browse(channel_id)
@@ -38,7 +52,7 @@ class LivechatController(http.Controller):
         info = request.env['im_livechat.channel'].get_livechat_info(channel.id, username=username)
         return request.render('im_livechat.loader', {'info': info, 'web_session_required': True}, headers=[('Content-Type', 'application/javascript')])
 
-    @http.route('/im_livechat/init', type='json', auth="public")
+    @http.route('/im_livechat/init', type='json', auth="public", cors="*")
     def livechat_init(self, channel_id):
         LivechatChannel = request.env['im_livechat.channel']
         available = len(LivechatChannel.browse(channel_id).get_available_users())
@@ -66,7 +80,7 @@ class LivechatController(http.Controller):
             'rule': rule,
         }
 
-    @http.route('/im_livechat/get_session', type="json", auth='public')
+    @http.route('/im_livechat/get_session', type="json", auth='public', cors="*")
     def get_session(self, channel_id, anonymous_name, **kwargs):
         user_id = None
         country_id = None
@@ -83,7 +97,7 @@ class LivechatController(http.Controller):
                 anonymous_name, country_id = _("%s (%s)") % (anonymous_name, country.name), country.id
         return request.env["im_livechat.channel"].with_context(lang=False).get_mail_channel(channel_id, anonymous_name, user_id, country_id)
 
-    @http.route('/im_livechat/feedback', type='json', auth='public')
+    @http.route('/im_livechat/feedback', type='json', auth='public', cors="*")
     def feedback(self, uuid, rate, reason=None, **kwargs):
         Channel = request.env['mail.channel']
         Rating = request.env['rating.rating']
@@ -114,7 +128,7 @@ class LivechatController(http.Controller):
             return rating.id
         return False
 
-    @http.route('/im_livechat/history', type="json", auth="public")
+    @http.route('/im_livechat/history', type="json", auth="public", cors="*")
     def history_pages(self, pid, channel_uuid, page_history=None):
         partner_ids = (pid, request.env.user.partner_id.id)
         channel = request.env['mail.channel'].sudo().search([('uuid', '=', channel_uuid), ('channel_partner_ids', 'in', partner_ids)])
@@ -122,7 +136,7 @@ class LivechatController(http.Controller):
             channel._send_history_message(pid, page_history)
         return True
 
-    @http.route('/im_livechat/notify_typing', type='json', auth='public')
+    @http.route('/im_livechat/notify_typing', type='json', auth='public', cors="*")
     def notify_typing(self, uuid, is_typing):
         """ Broadcast the typing notification of the website user to other channel members
             :param uuid: (string) the UUID of the livechat channel
diff --git a/addons/im_livechat/static/src/js/im_livechat.js b/addons/im_livechat/static/src/js/im_livechat.js
index f59a03e2040..964e9ef5d3e 100644
--- a/addons/im_livechat/static/src/js/im_livechat.js
+++ b/addons/im_livechat/static/src/js/im_livechat.js
@@ -190,15 +190,11 @@ var LivechatButton = Widget.extend({
      * @private
      */
     _loadQWebTemplate: function () {
-        var xml_files = ['/mail/static/src/xml/abstract_thread_window.xml',
-                         '/mail/static/src/xml/thread.xml',
-                         '/im_livechat/static/src/xml/im_livechat.xml'];
-        var defs = _.map(xml_files, function (tmpl) {
-            return session.rpc('/web/proxy/load', { path: tmpl }).then(function (xml) {
-                QWeb.add_template(xml);
+        return session.rpc('/im_livechat/load_templates').then(function (templates) {
+            _.each(templates, function (template) {
+                QWeb.add_template(template);
             });
         });
-        return $.when.apply($, defs);
     },
     /**
      * @private
diff --git a/addons/im_livechat/views/im_livechat_channel_templates.xml b/addons/im_livechat/views/im_livechat_channel_templates.xml
index 85861a185fa..d029ae32478 100644
--- a/addons/im_livechat/views/im_livechat_channel_templates.xml
+++ b/addons/im_livechat/views/im_livechat_channel_templates.xml
@@ -194,7 +194,7 @@
                     odoo.define('web.session', function (require) {
                         var Session = require('web.Session');
                         var modules = odoo._modules;
-                        return new Session(undefined, "<t t-esc="info['server_url']"/>", {modules:modules, use_cors: false});
+                        return new Session(undefined, "<t t-esc="info['server_url']"/>", {modules:modules, use_cors: true});
                     });
                     </t>
 
diff --git a/addons/mail/controllers/bus.py b/addons/mail/controllers/bus.py
index c900604ab06..912aae3cacd 100644
--- a/addons/mail/controllers/bus.py
+++ b/addons/mail/controllers/bus.py
@@ -34,7 +34,7 @@ class MailChatController(BusController):
     # --------------------------
     # Anonymous routes (Common Methods)
     # --------------------------
-    @route('/mail/chat_post', type="json", auth="none")
+    @route('/mail/chat_post', type="json", auth="none", cors="*")
     def mail_chat_post(self, uuid, message_content, **kwargs):
         # find the author from the user session, which can be None
         author_id = False  # message_post accept 'False' author_id, but not 'None'
@@ -46,7 +46,7 @@ class MailChatController(BusController):
         message = mail_channel.sudo().with_context(mail_create_nosubscribe=True).message_post(author_id=author_id, email_from=False, body=body, message_type='comment', subtype='mail.mt_comment')
         return message and message.id or False
 
-    @route(['/mail/chat_history'], type="json", auth="none")
+    @route(['/mail/chat_history'], type="json", auth="none", cors="*")
     def mail_chat_history(self, uuid, last_id=False, limit=20):
         channel = request.env["mail.channel"].sudo().search([('uuid', '=', uuid)], limit=1)
         if not channel:
diff --git a/addons/mail/static/src/xml/activity.xml b/addons/mail/static/src/xml/activity.xml
index dafad00b008..217e1a39f5c 100644
--- a/addons/mail/static/src/xml/activity.xml
+++ b/addons/mail/static/src/xml/activity.xml
@@ -98,7 +98,6 @@
                     <t t-set="fileupload_action" t-translation="off">/web/binary/upload_attachment</t>
                     <input type="hidden" name="model" t-att-value="activity.res_model"/>
                     <input type="hidden" name="id" t-att-value="activity.res_id"/>
-                    <input type="hidden" name="session_id" t-att-value="session.session_id"/>
                 </t>
             </span>
             <a role="button" href="#" class="btn btn-link btn-secondary text-muted o_edit_activity o_activity_link" t-att-data-activity-id="activity.id">
diff --git a/addons/mail/static/src/xml/composer.xml b/addons/mail/static/src/xml/composer.xml
index b9de0194e93..f405617affa 100644
--- a/addons/mail/static/src/xml/composer.xml
+++ b/addons/mail/static/src/xml/composer.xml
@@ -37,7 +37,6 @@
                 <t t-set="multi_upload" t-value="true"/>
                 <input type="hidden" name="model" value="mail.compose.message"/>
                 <input type="hidden" name="id" value="0"/>
-                <input type="hidden" name="session_id" t-att-value="widget.getSession().session_id"/>
             </t>
          </span>
     </div>
diff --git a/addons/mail/static/src/xml/web_kanban_activity.xml b/addons/mail/static/src/xml/web_kanban_activity.xml
index 698091e9875..4d6c290f11f 100644
--- a/addons/mail/static/src/xml/web_kanban_activity.xml
+++ b/addons/mail/static/src/xml/web_kanban_activity.xml
@@ -92,7 +92,6 @@
                             <t t-set="fileupload_action" t-translation="off">/web/binary/upload_attachment</t>
                             <input type="hidden" name="model" t-att-value="log.res_model"/>
                             <input type="hidden" name="id" t-att-value="log.res_id"/>
-                            <input type="hidden" name="session_id" t-att-value="session.session_id"/>
                         </t>
                     </span>
             </t>
diff --git a/addons/project/static/src/xml/project.xml b/addons/project/static/src/xml/project.xml
index ea69825c5a7..4be07b70fcd 100644
--- a/addons/project/static/src/xml/project.xml
+++ b/addons/project/static/src/xml/project.xml
@@ -15,7 +15,6 @@
                 <t t-set="fileupload_action" t-translation="off">/web/binary/upload_attachment</t>
                 <input type="hidden" name="model" t-att-value="widget.modelName" />
                 <input type="hidden" name="id" t-att-value="widget.id" />
-                <input type="hidden" name="session_id" t-att-value="widget.getSession().session_id" />
             </t>
         </span>
     </t>
diff --git a/addons/web/controllers/main.py b/addons/web/controllers/main.py
index 59b427cfe65..cf87240484c 100644
--- a/addons/web/controllers/main.py
+++ b/addons/web/controllers/main.py
@@ -640,22 +640,6 @@ class WebClient(http.Controller):
 
 class Proxy(http.Controller):
 
-    @http.route('/web/proxy/load', type='json', auth="none")
-    def load(self, path):
-        """ Proxies an HTTP request through a JSON request.
-
-        It is strongly recommended to not request binary files through this,
-        as the result will be a binary data blob as well.
-
-        :param path: actual request path
-        :return: file content
-        """
-        from werkzeug.test import Client
-        from werkzeug.wrappers import BaseResponse
-
-        base_url = request.httprequest.base_url
-        return Client(request.httprequest.app, BaseResponse).get(path, base_url=base_url).data
-
     @http.route('/web/proxy/post/<path:path>', type='http', auth='user', methods=['GET'])
     def post(self, path):
         """Effectively execute a POST request that was hooked through user login"""
diff --git a/addons/web/models/ir_http.py b/addons/web/models/ir_http.py
index e42c780d31e..414df12d8c5 100644
--- a/addons/web/models/ir_http.py
+++ b/addons/web/models/ir_http.py
@@ -23,7 +23,6 @@ class Http(models.AbstractModel):
         display_switch_company_menu = user.has_group('base.group_multi_company') and len(user.company_ids) > 1
         version_info = odoo.service.common.exp_version()
         return {
-            "session_id": request.session.sid,
             "uid": request.session.uid,
             "is_system": user._is_system() if request.session.uid else False,
             "is_admin": user._is_admin() if request.session.uid else False,
diff --git a/addons/web/static/src/js/core/ajax.js b/addons/web/static/src/js/core/ajax.js
index 1821d5a3be4..509126498bc 100644
--- a/addons/web/static/src/js/core/ajax.js
+++ b/addons/web/static/src/js/core/ajax.js
@@ -45,7 +45,6 @@ function genericJsonRpc (fct_name, params, settings, fct) {
         var def = $.Deferred();
         return def.reject.apply(def, ["communication"].concat(_.toArray(arguments)));
     });
-    // FIXME: jsonp?
     deferred.abort = function () {
         deferred.reject({message: "XmlHttpRequestError abort"}, $.Event('abort'));
         if (xhr.abort) {
@@ -106,80 +105,6 @@ function jsonRpc(url, fct_name, params, settings) {
     });
 }
 
-function jsonpRpc(url, fct_name, params, settings) {
-    settings = settings || {};
-    return genericJsonRpc(fct_name, params, settings, function(data) {
-        var payload_str = JSON.stringify(data, time.date_to_utc);
-        var payload_url = $.param({r:payload_str});
-        var force2step = settings.force2step || false;
-        delete settings.force2step;
-        var session_id = settings.session_id || null;
-        delete settings.session_id;
-        if (payload_url.length < 2000 && ! force2step) {
-            return $.ajax(url, _.extend({}, settings, {
-                url: url,
-                dataType: 'jsonp',
-                jsonp: 'jsonp',
-                type: 'GET',
-                cache: false,
-                data: {r: payload_str, session_id: session_id}
-            }));
-        } else {
-            var args = {session_id: session_id, id: data.id};
-            var ifid = _.uniqueId('oe_rpc_iframe');
-            var html = "<iframe src='javascript:false;' name='" + ifid + "' id='" + ifid + "' style='display:none'></iframe>";
-            var $iframe = $(html);
-            var nurl = 'jsonp=1&' + $.param(args);
-            nurl = url.indexOf("?") !== -1 ? url + "&" + nurl : url + "?" + nurl;
-            var $form = $('<form>')
-                        .attr('method', 'POST')
-                        .attr('target', ifid)
-                        .attr('enctype', "multipart/form-data")
-                        .attr('action', nurl)
-                        .append($('<input type="hidden" name="r" />').attr('value', payload_str))
-                        .hide()
-                        .appendTo($('body'));
-            var cleanUp = function() {
-                if ($iframe) {
-                    $iframe.unbind("load").remove();
-                }
-                $form.remove();
-            };
-            var deferred = $.Deferred();
-            // the first bind is fired up when the iframe is added to the DOM
-            $iframe.bind('load', function() {
-                // the second bind is fired up when the result of the form submission is received
-                $iframe.unbind('load').bind('load', function() {
-                    $.ajax({
-                        url: url,
-                        dataType: 'jsonp',
-                        jsonp: 'jsonp',
-                        type: 'GET',
-                        cache: false,
-                        data: {session_id: session_id, id: data.id}
-                    }).always(function() {
-                        cleanUp();
-                    }).done(function() {
-                        deferred.resolve.apply(deferred, arguments);
-                    }).fail(function() {
-                        deferred.reject.apply(deferred, arguments);
-                    });
-                });
-                // now that the iframe can receive data, we fill and submit the form
-                $form.submit();
-            });
-            // append the iframe to the DOM (will trigger the first load)
-            $form.after($iframe);
-            if (settings.timeout) {
-                realSetTimeout(function() {
-                    deferred.reject({});
-                }, settings.timeout);
-            }
-            return deferred;
-        }
-    });
-}
-
 // helper function to make a rpc with a function name hardcoded to 'call'
 function rpc(url, params, settings) {
     return jsonRpc(url, 'call', params, settings);
@@ -312,7 +237,7 @@ function get_file(options) {
         xhr.open('POST', options.url);
         data = new FormData();
         _.each(options.data || {}, function (v, k) {
-            data.append(k, v)
+            data.append(k, v);
         });
     }
     data.append('token', 'dummy-because-api-expects-one');
@@ -360,7 +285,7 @@ function get_file(options) {
                         name: String(xhr.status),
                         title: nodes.length > 0 ? nodes[0].textContent : '',
                     }
-                }
+                };
             }
             options.error(err);
         };
@@ -375,7 +300,7 @@ function get_file(options) {
         }
     };
     if (options.complete) {
-        xhr.onloadend = function () { options.complete(); }
+        xhr.onloadend = function () { options.complete(); };
     }
 
     xhr.send(data);
@@ -596,7 +521,6 @@ function loadLibs (libs) {
 
 var ajax = {
     jsonRpc: jsonRpc,
-    jsonpRpc: jsonpRpc,
     rpc: rpc,
     loadCSS: loadCSS,
     loadJS: loadJS,
diff --git a/addons/web/static/src/js/core/session.js b/addons/web/static/src/js/core/session.js
index 694285cccdc..7212b8ad76e 100644
--- a/addons/web/static/src/js/core/session.js
+++ b/addons/web/static/src/js/core/session.js
@@ -22,11 +22,8 @@ var Session = core.Class.extend(mixins.EventDispatcherMixin, {
     or `null` if the server to contact is the origin server.
     @param {Dict} options A dictionary that can contain the following options:
 
-        * "override_session": Default to false. If true, the current session object will
-          not try to re-use a previously created session id stored in a cookie.
-        * "session_id": Default to null. If specified, the specified session_id will be used
-          by this session object. Specifying this option automatically implies that the option
-          "override_session" is set to true.
+        * "modules"
+        * "use_cors"
      */
     init: function (parent, origin, options) {
         mixins.EventDispatcherMixin.init.call(this);
@@ -34,8 +31,6 @@ var Session = core.Class.extend(mixins.EventDispatcherMixin, {
         options = options || {};
         this.module_list = (options.modules && options.modules.slice()) || (window.odoo._modules && window.odoo._modules.slice()) || [];
         this.server = null;
-        this.session_id = options.session_id || null;
-        this.override_session = options.override_session || !!options.session_id || false;
         this.avoid_recursion = false;
         this.use_cors = options.use_cors || false;
         this.setup(origin);
@@ -61,7 +56,6 @@ var Session = core.Class.extend(mixins.EventDispatcherMixin, {
             this.origin = origin;
         this.prefix = this.origin;
         this.server = this.origin; // keep chs happy
-        this.origin_server = this.origin === window_origin;
         options = options || {};
         if ('use_cors' in options) {
             this.use_cors = options.use_cors;
@@ -139,7 +133,6 @@ var Session = core.Class.extend(mixins.EventDispatcherMixin, {
             if (!result.uid) {
                 return $.Deferred().reject();
             }
-            delete result.session_id;
             _.extend(self, result);
         });
     },
@@ -276,9 +269,6 @@ var Session = core.Class.extend(mixins.EventDispatcherMixin, {
         return this.currencies[currency_id];
     },
     get_file: function (options) {
-        if (this.override_session){
-            options.data.session_id = this.session_id;
-        }
         options.session = this;
         return ajax.get_file(options);
     },
@@ -290,29 +280,9 @@ var Session = core.Class.extend(mixins.EventDispatcherMixin, {
      */
     session_reload: function () {
         var result = _.extend({}, window.odoo.session_info);
-        delete result.session_id;
         _.extend(this, result);
         return $.when();
     },
-    check_session_id: function () {
-        var self = this;
-        if (this.avoid_recursion)
-            return $.when();
-        if (this.session_id)
-            return $.when(); // we already have the session id
-        if (!this.use_cors && (this.override_session || ! this.origin_server)) {
-            // If we don't use the origin server we consider we should always create a new session.
-            // Even if some browsers could support cookies when using jsonp that behavior is
-            // not consistent and the browser creators are tending to removing that feature.
-            this.avoid_recursion = true;
-            return this.rpc("/gen_session_id", {}).then(function (result) {
-                self.session_id = result;
-            }).always(function () {
-                self.avoid_recursion = false;
-            });
-        }
-        return $.when();
-    },
     /**
      * Executes an RPC call, registering the provided callbacks.
      *
@@ -333,57 +303,19 @@ var Session = core.Class.extend(mixins.EventDispatcherMixin, {
             options.headers["X-Debug-Mode"] = $.deparam($.param.querystring()).debug;
         }
 
-        var deferred = self.check_session_id();
-        var aborted = false;
-        var xhrDef;
-        deferred.abort = function () {
-            if (xhrDef) {
-                xhrDef.abort();
-            } else {
-                aborted = true;
-            }
-        };
+        // TODO: remove
+        if (! _.isString(url)) {
+            _.extend(options, url);
+            url = url.url;
+        }
+        if (self.use_cors) {
+            url = self.url(url, null);
+        }
 
-        var promise = deferred.then(function () {
-            if (aborted) {
-                var def = $.Deferred().reject({message: "XmlHttpRequestError abort"}, $.Event('abort'));
-                def.abort = function () {};
-                return def;
-            }
-            // TODO: remove
-            if (! _.isString(url)) {
-                _.extend(options, url);
-                url = url.url;
-            }
-            var fct;
-            if (self.origin_server) {
-                fct = ajax.jsonRpc;
-                if (self.override_session) {
-                    options.headers["X-Openerp-Session-Id"] = self.session_id || '';
-                }
-            } else if (self.use_cors) {
-                fct = ajax.jsonRpc;
-                url = self.url(url, null);
-                options.session_id = self.session_id || '';
-                if (self.override_session) {
-                    options.headers["X-Openerp-Session-Id"] = self.session_id || '';
-                }
-            } else {
-                fct = ajax.jsonpRpc;
-                url = self.url(url, null);
-                options.session_id = self.session_id || '';
-            }
-            xhrDef = fct(url, "call", params, options);
-            return xhrDef;
-        });
-
-        promise.abort = deferred.abort;
-        return promise;
+        return ajax.jsonRpc(url, "call", params, options);
     },
     url: function (path, params) {
         params = _.extend(params || {});
-        if (this.override_session || (! this.origin_server))
-            params.session_id = this.session_id;
         var qs = $.param(params);
         if (qs.length > 0)
             qs = "?" + qs;
diff --git a/addons/web/static/src/js/fields/basic_fields.js b/addons/web/static/src/js/fields/basic_fields.js
index b3cd17a38ee..ae080f45a11 100644
--- a/addons/web/static/src/js/fields/basic_fields.js
+++ b/addons/web/static/src/js/fields/basic_fields.js
@@ -1446,7 +1446,6 @@ var AbstractFieldBinary = AbstractField.extend({
                     self.on_file_uploaded(file.size, file.name, file.type, data);
                 };
             } else {
-                this.$('form.o_form_binary_form input[name=session_id]').val(this.getSession().session_id);
                 this.$('form.o_form_binary_form').submit();
             }
             this.$('.o_form_binary_progress').show();
diff --git a/addons/web/static/src/xml/base.xml b/addons/web/static/src/xml/base.xml
index 5e2f27ccc66..dc40c962333 100644
--- a/addons/web/static/src/xml/base.xml
+++ b/addons/web/static/src/xml/base.xml
@@ -378,7 +378,6 @@
                         <t t-set="multi_upload" t-value="true"/>
                         <input type="hidden" name="model" t-att-value="widget.env and widget.env.model"/>
                         <input type="hidden" name="id" t-att-value="widget.env.activeIds[0]"/>
-                        <input type="hidden" name="session_id" t-att-value="widget.getSession().session_id" t-if="widget.getSession().override_session"/>
                         <span>Add...</span>
                     </t>
                 </div>
@@ -998,7 +997,6 @@
         <form class="o_form_binary_form" t-att-target="fileupload_id"
               method="post" enctype="multipart/form-data" t-att-action="fileupload_action || '/web/binary/upload'">
             <input type="hidden" name="csrf_token" t-att-value="csrf_token"/>
-            <input type="hidden" name="session_id" value="" t-if="widget.getSession().override_session"/>
             <input type="hidden" name="callback" t-att-value="fileupload_id"/>
             <input t-if="widget.image_only" type="file" class="o_input_file" name="ufile" accept="image/*"/>
             <input t-if="!widget.image_only" type="file" class="o_input_file" name="ufile" t-att="{'multiple': multi_upload ? 'multiple' : null}"/>
@@ -1042,7 +1040,6 @@
             <t t-set="multi_upload" t-value="true"/>
             <input type="hidden" name="model" t-att-value="widget.model"/>
             <input type="hidden" name="id" value="0"/>
-            <input t-if="widget.getSession().override_session" type="hidden" name="session_id" t-att-value="widget.getSession().session_id"/>
         </t>
     </div>
 </div>
@@ -1567,7 +1564,6 @@
                 <t t-set="multi_upload" t-value="true"/>
                 <input type="hidden" name="model" t-att-value="widget.res_model"/>
                 <input type="hidden" name="id" t-att-value="widget.res_id"/>
-                <input type="hidden" name="session_id" t-att-value="widget.getSession().session_id"/>
             </t>
         </span>
     </button>
diff --git a/addons/website_sale/static/src/js/website_sale_tour_shop_customize.js b/addons/website_sale/static/src/js/website_sale_tour_shop_customize.js
index 009eb44b436..da48b761560 100644
--- a/addons/website_sale/static/src/js/website_sale_tour_shop_customize.js
+++ b/addons/website_sale/static/src/js/website_sale_tour_shop_customize.js
@@ -47,8 +47,8 @@ odoo.define('website_sale.tour_shop_customize', function (require) {
                         args: ['product.group_product_variant', false],
                         kwargs: {}
                     };
-                    ajax.jsonpRpc('/web/dataset/call_kw', 'call', get_group_payload).then(function(group_id) {
-                        ajax.jsonpRpc('/web/dataset/call_kw', 'call', {
+                    ajax.jsonRpc('/web/dataset/call_kw', 'call', get_group_payload).then(function(group_id) {
+                        ajax.jsonRpc('/web/dataset/call_kw', 'call', {
                             model: 'res.groups',
                             method: 'write',
                             args: [group_id, {'users': [[4, 1]]}],
diff --git a/odoo/http.py b/odoo/http.py
index 3b44a7d2054..886fecc48ba 100644
--- a/odoo/http.py
+++ b/odoo/http.py
@@ -302,7 +302,7 @@ class WebRequest(object):
     def _handle_exception(self, exception):
         """Called within an except block to allow converting exceptions
            to abitrary responses. Anything returned (except None) will
-           be used as response.""" 
+           be used as response."""
         self._failed = exception # prevent tx commit
         if not isinstance(exception, NO_POSTMORTEM) \
                 and not isinstance(exception, werkzeug.exceptions.HTTPException):
@@ -579,34 +579,14 @@ class JsonRequest(WebRequest):
     def __init__(self, *args):
         super(JsonRequest, self).__init__(*args)
 
-        self.jsonp_handler = None
         self.params = {}
 
         args = self.httprequest.args
-        jsonp = args.get('jsonp')
-        self.jsonp = jsonp
         request = None
         request_id = args.get('id')
-        
-        if jsonp and self.httprequest.method == 'POST':
-            # jsonp 2 steps step1 POST: save call
-            def handler():
-                self.session['jsonp_request_%s' % (request_id,)] = self.httprequest.form['r']
-                self.session.modified = True
-                headers=[('Content-Type', 'text/plain; charset=utf-8')]
-                r = werkzeug.wrappers.Response(request_id, headers=headers)
-                return r
-            self.jsonp_handler = handler
-            return
-        elif jsonp and args.get('r'):
-            # jsonp method GET
-            request = args.get('r')
-        elif jsonp and request_id:
-            # jsonp 2 steps step2 GET: run and return result
-            request = self.session.pop('jsonp_request_%s' % (request_id,), '{}')
-        else:
-            # regular jsonrpc2
-            request = self.httprequest.get_data().decode(self.httprequest.charset)
+
+        # regular jsonrpc2
+        request = self.httprequest.get_data().decode(self.httprequest.charset)
 
         # Read POST content or POST Form Data named "request"
         try:
@@ -630,16 +610,8 @@ class JsonRequest(WebRequest):
         if result is not None:
             response['result'] = result
 
-        if self.jsonp:
-            # If we use jsonp, that's mean we are called from another host
-            # Some browser (IE and Safari) do no allow third party cookies
-            # We need then to manage http sessions manually.
-            response['session_id'] = self.session.sid
-            mime = 'application/javascript'
-            body = "%s(%s);" % (self.jsonp, json.dumps(response, default=date_utils.json_default))
-        else:
-            mime = 'application/json'
-            body = json.dumps(response, default=date_utils.json_default)
+        mime = 'application/json'
+        body = json.dumps(response, default=date_utils.json_default)
 
         return Response(
             body, status=error and error.pop('http_status', 200) or 200,
@@ -674,8 +646,6 @@ class JsonRequest(WebRequest):
             return self._json_response(error=error)
 
     def dispatch(self):
-        if self.jsonp_handler:
-            return self.jsonp_handler()
         try:
             rpc_request_flag = rpc_request.isEnabledFor(logging.DEBUG)
             rpc_response_flag = rpc_response.isEnabledFor(logging.DEBUG)
@@ -1388,8 +1358,6 @@ class Root(object):
 
     def get_request(self, httprequest):
         # deduce type of request
-        if httprequest.args.get('jsonp'):
-            return JsonRequest(httprequest)
         if httprequest.mimetype in ("application/json", "application/json-rpc"):
             return JsonRequest(httprequest)
         else:
@@ -1647,15 +1615,5 @@ def content_disposition(filename):
 
     return "attachment; filename*=UTF-8''%s" % escaped
 
-#----------------------------------------------------------
-# RPC controller
-#----------------------------------------------------------
-class CommonController(Controller):
-
-    @route('/gen_session_id', type='json', auth="none")
-    def gen_session_id(self):
-        nsession = root.session_store.new()
-        return nsession.sid
-
 #  main wsgi handler
 root = Root()