diff --git a/package.json b/package.json
index ccc149da..696e57da 100644
--- a/package.json
+++ b/package.json
@@ -45,6 +45,7 @@
   "homepage": "https://github.com/mozilla/send/",
   "license": "MPL-2.0",
   "repository": "mozilla/send",
+  "availableLanguages": ["en-US"],
   "scripts": {
     "build": "npm-run-all build:*",
     "build:upload": "browserify frontend/src/upload.js -g uglifyify -o public/upload.js",
diff --git a/server/config.js b/server/config.js
index 5c6e540a..83e3e21e 100644
--- a/server/config.js
+++ b/server/config.js
@@ -46,6 +46,11 @@ const conf = convict({
     format: Number,
     default: 86400,
     env: 'EXPIRE_SECONDS'
+  },
+  l10n_dev: {
+    format: Boolean,
+    default: false,
+    env: 'L10N_DEV'
   }
 });
 
diff --git a/server/server.js b/server/server.js
index 49fbe7e0..b12f3f57 100644
--- a/server/server.js
+++ b/server/server.js
@@ -9,6 +9,7 @@ const conf = require('./config.js');
 const storage = require('./storage.js');
 const Raven = require('raven');
 const crypto = require('crypto');
+const fs = require('fs');
 
 if (conf.sentry_dsn) {
   Raven.config(conf.sentry_dsn).install();
@@ -22,11 +23,34 @@ const STATIC_PATH = path.join(__dirname, '../public');
 
 const app = express();
 
+function allLangs() {
+  return fs
+    .readdirSync(path.join(STATIC_PATH, 'locales'))
+    .map(function(f) {
+      return f.split('.')[0];
+    })
+    .join(',');
+}
+
+function prodLangs() {
+  return require(path.join(
+    __dirname,
+    '..',
+    'package.json'
+  )).availableLanguages.join(',');
+}
+
+const availableLanguages = conf.l10n_dev ? allLangs() : prodLangs();
+
 app.engine(
   'handlebars',
   exphbs({
     defaultLayout: 'main',
-    partialsDir: 'views/partials/'
+    partialsDir: 'views/partials/',
+    helpers: {
+      availableLanguages,
+      l10nDev: conf.l10n_dev
+    }
   })
 );
 app.set('view engine', 'handlebars');
diff --git a/views/layouts/main.handlebars b/views/layouts/main.handlebars
index cf00952f..4609d7c3 100644
--- a/views/layouts/main.handlebars
+++ b/views/layouts/main.handlebars
@@ -8,7 +8,7 @@
   <meta name="viewport" content="width=device-width, initial-scale=1">
 
   <meta name="defaultLanguage" content="en-US">
-  <meta name="availableLanguages" content="en-US">
+  <meta name="availableLanguages" content="{{availableLanguages}}">
 
   <link rel="icon" type="image/png" href="/resources/favicon-32x32.png" sizes="32x32" />
   <link rel="localization" href="/locales/{locale}/send.ftl">