diff --git a/frontend/src/index.js b/frontend/src/index.js
index 4dd9b371..eb34d78c 100644
--- a/frontend/src/index.js
+++ b/frontend/src/index.js
@@ -1,12 +1,12 @@
 import { IntlProvider } from 'react-intl-redux';
 import { BrowserRouter } from 'react-router-dom';
 import { Provider } from 'react-redux';
+import qs from 'querystring';
 import a11y from 'react-a11y';
 import ReactDOM from 'react-dom';
 import React from 'react';
 
 import App from '@containers/app';
-// import MockState from './mock-state.json';
 import MockStateTesting from './mock-state-testing.json';
 import MockState from './mock-state.json';
 import LeakDatasets from './dataset-leak.json';
@@ -19,9 +19,11 @@ if (process.env.NODE_ENV !== 'production') {
   });
 }
 
-// TODO want ot be able to switch whic mock state to use
-// based on a query string
-const mockState = MockStateTesting;
+const query = qs.parse(window.location.search.replace(/^\?/, ''));
+const mockState = query.mock !== 'all'
+  ? MockStateTesting
+  : MockState;
+
 // node_memory_rss_bytes
 // node_memory_heap_total_bytes
 // node_memory_heap_used_bytes
diff --git a/package.json b/package.json
index 9ed8b9f9..bdade50d 100644
--- a/package.json
+++ b/package.json
@@ -22,6 +22,7 @@
     "husky": "^0.13.1",
     "license-to-fail": "^2.2.0",
     "lodash.findindex": "^4.6.0",
+    "querystring": "^0.2.0",
     "style-loader": "^0.13.1"
   },
   "devDependencies": {
diff --git a/yarn.lock b/yarn.lock
index 14e16c7f..0de89135 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1,7 +1,5 @@
 # THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
 # yarn lockfile v1
-
-
 abbrev@1:
   version "1.0.9"
   resolved "https://registry.yarnpkg.com/abbrev/-/abbrev-1.0.9.tgz#91b4792588a7738c25f35dd6f63752a2f8776135"
@@ -178,7 +176,7 @@ inflight@^1.0.4:
     once "^1.3.0"
     wrappy "1"
 
-inherits@2, inherits@~2.0.1:
+inherits@~2.0.1, inherits@2:
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.3.tgz#633c2c83e3da42a502f52466022480f4208261de"
 
@@ -308,6 +306,10 @@ process-nextick-args@~1.0.6:
   version "1.0.7"
   resolved "https://registry.yarnpkg.com/process-nextick-args/-/process-nextick-args-1.0.7.tgz#150e20b756590ad3f91093f25a4f2ad8bff30ba3"
 
+querystring:
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/querystring/-/querystring-0.2.0.tgz#b209849203bb25df820da756e747005878521620"
+
 read-installed@~4.0.3:
   version "4.0.3"
   resolved "https://registry.yarnpkg.com/read-installed/-/read-installed-4.0.3.tgz#ff9b8b67f187d1e4c29b9feb31f6b223acd19067"
@@ -468,3 +470,4 @@ xmlbuilder@~4.1.0:
 xtend@~4.0.0, xtend@~4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/xtend/-/xtend-4.0.1.tgz#a5c6d532be656e23db820efb943a1f04998d63af"
+