diff --git a/src/Lifecycle.js b/src/Lifecycle.js
index f7579cf3c0e..fbb68481ad7 100644
--- a/src/Lifecycle.js
+++ b/src/Lifecycle.js
@@ -31,7 +31,8 @@ import Modal from './Modal';
 import sdk from './index';
 import ActiveWidgetStore from './stores/ActiveWidgetStore';
 import PlatformPeg from "./PlatformPeg";
-import {sendLoginRequest} from "./Login";
+import { sendLoginRequest } from "./Login";
+import * as StorageManager from './utils/StorageManager';
 
 /**
  * Called at startup, to attempt to build a logged-in Matrix session. It tries
@@ -353,6 +354,8 @@ async function _doSetLoggedIn(credentials, clearStorage) {
         await _clearStorage();
     }
 
+    await StorageManager.checkConsistency();
+
     Analytics.setLoggedIn(credentials.guest, credentials.homeserverUrl, credentials.identityServerUrl);
 
     if (localStorage) {
diff --git a/src/MatrixClientPeg.js b/src/MatrixClientPeg.js
index ad20988d9eb..f5994921de4 100644
--- a/src/MatrixClientPeg.js
+++ b/src/MatrixClientPeg.js
@@ -171,7 +171,7 @@ class MatrixClientPeg {
         return matches[1];
     }
 
-    _createClient(creds: MatrixClientCreds, useIndexedDb) {
+    _createClient(creds: MatrixClientCreds) {
         const opts = {
             baseUrl: creds.homeserverUrl,
             idBaseUrl: creds.identityServerUrl,
@@ -183,7 +183,7 @@ class MatrixClientPeg {
             verificationMethods: [verificationMethods.SAS]
         };
 
-        this.matrixClient = createMatrixClient(opts, useIndexedDb);
+        this.matrixClient = createMatrixClient(opts);
 
         // we're going to add eventlisteners for each matrix event tile, so the
         // potential number of event listeners is quite high.
diff --git a/src/utils/StorageManager.js b/src/utils/StorageManager.js
new file mode 100644
index 00000000000..4774d3b7e1e
--- /dev/null
+++ b/src/utils/StorageManager.js
@@ -0,0 +1,90 @@
+/*
+Copyright 2019 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import Matrix from 'matrix-js-sdk';
+
+const localStorage = window.localStorage;
+
+// just *accessing* indexedDB throws an exception in firefox with
+// indexeddb disabled.
+let indexedDB;
+try {
+    indexedDB = window.indexedDB;
+} catch (e) {}
+
+// The JS SDK will add a prefix of "matrix-js-sdk:" to the sync store name.
+const SYNC_STORE_NAME = "riot-web-sync";
+const CRYPTO_STORE_NAME = "matrix-js-sdk:crypto";
+
+function log(msg) {
+    console.log(`StorageManager: ${msg}`);
+}
+
+function error(msg) {
+    console.error(`StorageManager: ${msg}`);
+}
+
+export async function checkConsistency() {
+    log("Checking storage consistency");
+    log(`Local storage supported? ${!!localStorage}`);
+    log(`IndexedDB supported? ${!!indexedDB}`);
+
+    let dataInLocalStorage = false;
+    let dataInCryptoStore = false;
+    let healthy = true;
+
+    if (localStorage) {
+        dataInLocalStorage = localStorage.length > 0;
+        log(`Local storage contains data? ${dataInLocalStorage}`);
+    } else {
+        healthy = false;
+        error("Local storage cannot be used on this browser");
+    }
+
+    if (indexedDB && localStorage) {
+        const dataInSyncStore = await Matrix.IndexedDBStore.exists(
+            indexedDB, SYNC_STORE_NAME,
+        );
+        log(`Sync store contains data? ${dataInSyncStore}`);
+    } else {
+        healthy = false;
+        error("Sync store cannot be used on this browser");
+    }
+
+    if (indexedDB) {
+        dataInCryptoStore = await Matrix.IndexedDBCryptoStore.exists(
+            indexedDB, CRYPTO_STORE_NAME,
+        );
+        log(`Crypto store contains data? ${dataInCryptoStore}`);
+    } else {
+        healthy = false;
+        error("Crypto store cannot be used on this browser");
+    }
+
+    if (dataInLocalStorage && !dataInCryptoStore) {
+        healthy = false;
+        error(
+            "Data exists in local storage but not in crypto store. " +
+            "IndexedDB storage has likely been evicted by the browser!",
+        );
+    }
+
+    if (healthy) {
+        log("Storage consistency checks passed");
+    } else {
+        error("Storage consistency checks failed");
+    }
+}
diff --git a/src/utils/createMatrixClient.js b/src/utils/createMatrixClient.js
index 040f1e96cbc..dee93244606 100644
--- a/src/utils/createMatrixClient.js
+++ b/src/utils/createMatrixClient.js
@@ -32,23 +32,18 @@ try {
  * @param {Object} opts  options to pass to Matrix.createClient. This will be
  *    extended with `sessionStore` and `store` members.
  *
- * @param {bool} useIndexedDb True to attempt to use indexeddb, or false to force
- *     use of the memory store. Default: true.
- *
  * @property {string} indexedDbWorkerScript  Optional URL for a web worker script
  *    for IndexedDB store operations. By default, indexeddb ops are done on
  *    the main thread.
  *
  * @returns {MatrixClient} the newly-created MatrixClient
  */
-export default function createMatrixClient(opts, useIndexedDb) {
-    if (useIndexedDb === undefined) useIndexedDb = true;
-
+export default function createMatrixClient(opts) {
     const storeOpts = {
         useAuthorizationHeader: true,
     };
 
-    if (indexedDB && localStorage && useIndexedDb) {
+    if (indexedDB && localStorage) {
         storeOpts.store = new Matrix.IndexedDBStore({
             indexedDB: indexedDB,
             dbName: "riot-web-sync",
@@ -61,7 +56,7 @@ export default function createMatrixClient(opts, useIndexedDb) {
         storeOpts.sessionStore = new Matrix.WebStorageSessionStore(localStorage);
     }
 
-    if (indexedDB && useIndexedDb) {
+    if (indexedDB) {
         storeOpts.cryptoStore = new Matrix.IndexedDBCryptoStore(
             indexedDB, "matrix-js-sdk:crypto",
         );