diff --git a/estate/assets/js/api/messages.js b/estate/assets/js/api/messages.js
index 8587867..046b19c 100644
--- a/estate/assets/js/api/messages.js
+++ b/estate/assets/js/api/messages.js
@@ -33,7 +33,6 @@ export function error(message) {
 export function handleResponseError(err) {
     if (err.response || err.errors) {
         var data = err.response.data
-        console.log(data)
         var message = ""
         if (isArray(data.errors)) {
             each(data.errors, (item) => {
diff --git a/estate/assets/js/api/terraform.js b/estate/assets/js/api/terraform.js
index 1f8c2f1..255bd2a 100644
--- a/estate/assets/js/api/terraform.js
+++ b/estate/assets/js/api/terraform.js
@@ -118,6 +118,17 @@ export function updateTemplateOfTemplateInstance(id) {
     return req
 }
 
+export function diffTemplateInstance(id) {
+    const req = axios.get(`/api/v1/terraform/templateinstance/${id}/diff_latest/`)
+    req.then((res) => {
+        dispatch({
+            type: "LOAD_TEMPLATE_INSTANCE_DIFF",
+            payload: res.data
+        })
+    }, messages.handleResponseError)
+    return req
+}
+
 export function removeTemplateFromNamespace(slug, id) {
     const req = axios.delete(`/api/v1/terraform/templateinstance/${id}/`)
     req.then(() => {
diff --git a/estate/assets/js/components/DiffModal.jsx b/estate/assets/js/components/DiffModal.jsx
new file mode 100644
index 0000000..627563d
--- /dev/null
+++ b/estate/assets/js/components/DiffModal.jsx
@@ -0,0 +1,27 @@
+import React from "react"
+import Diff from "react-diff"
+import Modal from "./Modal"
+
+
+export default class ConfirmModal extends React.Component {
+    getResult() {
+        return {}
+    }
+    render() {
+        return(
+            <Modal
+                className={this.props.className}
+                buttonText={this.props.buttonText}
+                titleText={this.props.titleText}
+                tooltipText={this.props.tooltipText}
+                tooltipDelay={this.props.tooltipDelay}
+                disabled={this.props.disabled}
+                getResult={this.getResult.bind(this)}
+                performLoad={this.props.load}
+                performSubmit={this.props.callback}
+            >
+                <Diff inputA={this.props.diff_old || ""} inputB={this.props.diff_new || ""} type={this.props.diff_type || "chars"} />
+            </Modal>
+        )
+    }
+}
diff --git a/estate/assets/js/components/Modal.jsx b/estate/assets/js/components/Modal.jsx
index dee585a..078dd3b 100644
--- a/estate/assets/js/components/Modal.jsx
+++ b/estate/assets/js/components/Modal.jsx
@@ -34,6 +34,8 @@ class Modal extends React.Component {
         this.closeModal()
     }
     openModal() {
+        if (this.props.performLoad)
+            this.props.performLoad()
         if (!this.props.disabled)
             this.setState({modalIsOpen: true})
     }
diff --git a/estate/assets/js/components/TerraformNamespaceItem.jsx b/estate/assets/js/components/TerraformNamespaceItem.jsx
index a9a30f1..5c38174 100644
--- a/estate/assets/js/components/TerraformNamespaceItem.jsx
+++ b/estate/assets/js/components/TerraformNamespaceItem.jsx
@@ -7,6 +7,7 @@ import ReactTooltip from "react-tooltip"
 import Ansi from "ansi-to-react"
 import Editor from "./Editor"
 import ConfirmModal from "./ConfirmModal"
+import DiffModal from "./DiffModal"
 import TerraformNamespaceAddFileModal from "./TerraformNamespaceAddFileModal"
 import TerraformTemplateRenderer from "./TerraformTemplateRenderer"
 import * as terraform from "../api/terraform"
@@ -297,12 +298,21 @@ class TerraformNamespaceItem extends React.Component {
         })
         return elements
     }
-    createTemplateUpdateButton(id) {
+    createTemplateUpdateButton(locked, templateInstance) {
+        if (locked)
+            return null
+        if (!templateInstance.is_outdated)
+            return null
+        var id = templateInstance.pk
         return (
-            <ConfirmModal className="flashing text-danger glyphicon glyphicon-exclamation-sign"
+            <DiffModal className="flashing text-danger glyphicon glyphicon-exclamation-sign"
                 buttonText=" "
                 titleText="Update to latest template version?"
                 tooltipText="Click to update to latest version"
+                diff_old={JSON.stringify(this.props.diffTemplateOld, null, 2)}
+                diff_new={JSON.stringify(this.props.diffTemplateNew, null, 2)}
+                diff_type="json"
+                load={this.props.diffTemplateInstance.bind(null, id)}
                 callback={this.props.updateTemplateOfTemplateInstance.bind(null, id)} />
         )
     }
@@ -326,7 +336,6 @@ class TerraformNamespaceItem extends React.Component {
                 <div className="col-xs-12">
                     <h1 className="page-header">
                         {templateInstance.title}
-                        {locked ? null :
                         <div className="pull-right">
                             { templateInstance.nextDisable ?
                                 <div className="btn btn-success btn-inline" onClick={this.onTemplateToggleDisable.bind(this, index, false)}>Enable</div>
@@ -334,9 +343,9 @@ class TerraformNamespaceItem extends React.Component {
                                 <div className="btn btn-danger btn-inline" onClick={this.onTemplateToggleDisable.bind(this, index, true)}>Disable</div>
                             }
                             {/*<div className="btn btn-default btn-inline">Update</div>*/}
-                            <span> [ {templateInstance.template.title} : {templateInstance.template.version} { templateInstance.is_outdated ? this.createTemplateUpdateButton.bind(this)(templateInstance.pk) : "" } ]</span>
+                            <span> [ {templateInstance.template.title} : {templateInstance.template.version} { this.createTemplateUpdateButton.bind(this)(locked, templateInstance) } ]
+                            </span>
                         </div>
-                        }
                     </h1>
                 </div>
                 <div className="col-xs-12">
@@ -635,6 +644,9 @@ const mapStateToProps = (state, ownProps) => {
         updateFile: terraform.updateFile,
         updateTemplateInstance: terraform.updateTemplateInstance,
         updateTemplateOfTemplateInstance: terraform.updateTemplateOfTemplateInstance,
+        diffTemplateInstance: terraform.diffTemplateInstance,
+        diffTemplateOld: state.terraform.diffTemplateOld,
+        diffTemplateNew: state.terraform.diffTemplateNew,
         planOutput: state.terraform.planOutput,
         applyOutput: state.terraform.applyOutput,
         stateObject: state.terraform.stateObject,
diff --git a/estate/assets/js/components/TerraformTemplateItem.jsx b/estate/assets/js/components/TerraformTemplateItem.jsx
index 64d3066..9c78146 100644
--- a/estate/assets/js/components/TerraformTemplateItem.jsx
+++ b/estate/assets/js/components/TerraformTemplateItem.jsx
@@ -186,20 +186,20 @@ class TerraformTemplateItem extends React.Component {
                 <h1 className="page-header">Edit <span className="pull-right">{template.version}</span></h1>
                 <div className="row">
                     <div className="col-xs-12">
-                        <Editor title="Description" options={{ mode: "markdown" }} content={template.description} onUpdateContent={this.onDescriptionChange.bind(this)} />
+                        <Editor title="Description" options={{ mode: "markdown" }} content={this.state.description} initialContent={template.description} onUpdateContent={this.onDescriptionChange.bind(this)} />
                     </div>
                 </div>
                 <div className="row">
                     <div className="col-xs-6">
-                        <Editor title={this.createJsonSchemaHeader()} content={template.json_schema || "{}"} onUpdateContent={this.onJsonSchemaChange.bind(this)} />
+                        <Editor title={this.createJsonSchemaHeader()} content={this.state.json_schema} initialContent={template.json_schema || "{}"} onUpdateContent={this.onJsonSchemaChange.bind(this)} />
                     </div>
                     <div className="col-xs-6">
-                        <Editor title="UI Schema" content={template.ui_schema || "{}"} onUpdateContent={this.onUISchemaChange.bind(this)} />
+                        <Editor title="UI Schema" content={this.state.ui_schema} initialContent={template.ui_schema || "{}"} onUpdateContent={this.onUISchemaChange.bind(this)} />
                     </div>
                 </div>
                 <div className="row">
                     <div className="col-xs-12">
-                        <Editor title={this.createTemplateBodyHeader()} options={options} content={template.body} onUpdateContent={this.onBodyChange.bind(this)} />
+                        <Editor title={this.createTemplateBodyHeader()} options={options} content={this.state.body} initialContent={template.body} onUpdateContent={this.onBodyChange.bind(this)} />
                     </div>
                 </div>
             </WithLoading>
diff --git a/estate/assets/js/reducers/terraform.js b/estate/assets/js/reducers/terraform.js
index 13a464d..445dea4 100644
--- a/estate/assets/js/reducers/terraform.js
+++ b/estate/assets/js/reducers/terraform.js
@@ -17,6 +17,8 @@ var initialState = {
     files: [],
     templates: [],
     renderedTemplate: "{}",
+    diffTemplateOld: "{}",
+    diffTemplateNew: "{}",
     templatesPage: 0,
     templatesPages: 0,
 }
@@ -145,4 +147,10 @@ export default createReducer(initialState, {
         state = set(["renderedTemplate"])(action.payload)(state)
         return state
     },
+
+    ["LOAD_TEMPLATE_INSTANCE_DIFF"]: (state, action) => {
+        state = set(["diffTemplateOld"])(action.payload.old)(state)
+        state = set(["diffTemplateNew"])(action.payload.new)(state)
+        return state
+    }
 })
diff --git a/estate/settings/drf.py b/estate/settings/drf.py
index e4a0aec..d831b9b 100644
--- a/estate/settings/drf.py
+++ b/estate/settings/drf.py
@@ -32,6 +32,7 @@ def api_exception_handler(exc, context):
     'DEFAULT_AUTHENTICATION_CLASSES': (
         'rest_framework.authentication.BasicAuthentication',
         'rest_framework.authentication.TokenAuthentication',
+        'rest_framework.authentication.SessionAuthentication',
     ),
     'DEFAULT_PERMISSION_CLASSES': (
         'rest_framework.permissions.IsAuthenticated',
@@ -61,7 +62,7 @@ def api_exception_handler(exc, context):
     },
     'LOGIN_URL': 'rest_framework:login',
     'LOGOUT_URL': 'rest_framework:logout',
-    'USE_SESSION_AUTH': False,
+    'USE_SESSION_AUTH': True,
     'APIS_SORTER': 'alpha',
     'JSON_EDITOR': True,
     'VALIDATOR_URL': None
diff --git a/estate/terraform/views/template.py b/estate/terraform/views/template.py
index 216547f..1b3ee5e 100644
--- a/estate/terraform/views/template.py
+++ b/estate/terraform/views/template.py
@@ -6,6 +6,7 @@
 from estate.core.views import HistoricalSerializer, HistoryMixin, OwnsNamespace
 from estate.core import renderer
 
+
 Namespace = apps.get_model("terraform.Namespace")
 Template = apps.get_model("terraform.Template")
 TemplateInstance = apps.get_model("terraform.TemplateInstance")
@@ -127,6 +128,11 @@ def update(self, instance, validated_data):
         return super(TemplateInstanceSerializer, self).update(instance, validated_data)
 
 
+class TemplateDiffSerializer(serializers.Serializer):
+    old = serializers.JSONField(read_only=True)
+    new = serializers.JSONField(read_only=True)
+
+
 class TemplateInstanceFilter(filters.FilterSet):
 
     class Meta:
@@ -136,13 +142,47 @@ class Meta:
 
 class TemplateInstanceApiView(HistoryMixin, viewsets.ModelViewSet):
     queryset = TemplateInstance.objects.all()
-    serializer_class = TemplateInstanceSerializer
+    serializers = {
+        "default": TemplateInstanceSerializer,
+        "diff_latest": TemplateDiffSerializer,
+    }
     filter_class = TemplateInstanceFilter
     permission_classes = (OwnsNamespace, )
     filter_fields = ("slug",)
     search_fields = ("title",)
     ordering_fields = ("title", "created", "modified")
 
+    def get_serializer_class(self):
+        return self.serializers.get(self.action, self.serializers["default"])
+
+    @decorators.detail_route(methods=["GET"])
+    def diff_latest(self, request, *args, **kwargs):
+        instance = self.get_object()
+        latest_template = Template.all_objects.get(pk=instance.template.id)
+        old_data = {
+            "template_str": instance.template.body,
+            "inputs": instance.inputs,
+            "overrides": instance.overrides,
+            "disable": instance.disable,
+        }
+        new_data = {
+            "template_str": latest_template.body,
+            "inputs": instance.inputs,
+            "overrides": instance.overrides,
+            "disable": instance.disable,
+        }
+        try:
+            data = {
+                "old": renderer.render_template(**old_data),
+                "new": renderer.render_template(**new_data),
+            }
+        except Exception as e:
+            raise exceptions.APIException(str(e))
+        serializer = self.get_serializer(data=data)
+        serializer.is_valid(raise_exception=True)
+        headers = self.get_success_headers(serializer.data)
+        return response.Response(data, status=status.HTTP_200_OK, headers=headers)
+
     @decorators.detail_route(methods=["POST"])
     def update_template(self, request, *args, **kwargs):
         instance = self.get_object()
diff --git a/estate/urls.py b/estate/urls.py
index af6e78a..cf47903 100644
--- a/estate/urls.py
+++ b/estate/urls.py
@@ -23,7 +23,6 @@
     url(r'^api/$', RedirectView.as_view(url='/api/swagger/')),
     url(r'^api/schema/$', base_schema_view),
     url(r'^api/swagger/', swagger_view),
-    url(r'^api/docs/', include_docs_urls(title=title), name="api-docs"),
     url(r'^api/v1/terraform/', include('estate.terraform.urls')),
     # Acts as a catchall for everything else and react router will take over
     url(r'^', TemplateView.as_view(template_name='index.html')),