diff --git a/website/views/layouts/layout-customer.ejs b/website/views/layouts/layout-customer.ejs
index f740b2fc5e..64abee9950 100644
--- a/website/views/layouts/layout-customer.ejs
+++ b/website/views/layouts/layout-customer.ejs
@@ -227,9 +227,9 @@
           msedge: '16',
           // msie: '11',
           safari: '10',//« earliest version to eliminate rare bug where `window.location` doesn't exist momentarily after doing a server-side redirect
-          firefox: '28',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
-          chrome: '29',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
-          opera: '17',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          firefox: '54',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          chrome: '51',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          opera: '38',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
         };
         var LATEST_SUPPORTED_VERSION_BY_BROWSER_NAME = {
           'microsoft edge': LATEST_SUPPORTED_VERSION_BY_USER_AGENT.msedge,
diff --git a/website/views/layouts/layout-landing.ejs b/website/views/layouts/layout-landing.ejs
index f73f9d5d31..980d97f3c9 100644
--- a/website/views/layouts/layout-landing.ejs
+++ b/website/views/layouts/layout-landing.ejs
@@ -229,9 +229,9 @@
           msedge: '16',
           // msie: '11',
           safari: '10',//« earliest version to eliminate rare bug where `window.location` doesn't exist momentarily after doing a server-side redirect
-          firefox: '28',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
-          chrome: '29',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
-          opera: '17',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          firefox: '54',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          chrome: '51',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          opera: '38',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
         };
         var LATEST_SUPPORTED_VERSION_BY_BROWSER_NAME = {
           'microsoft edge': LATEST_SUPPORTED_VERSION_BY_USER_AGENT.msedge,
diff --git a/website/views/layouts/layout.ejs b/website/views/layouts/layout.ejs
index d8dd0912f5..116163f8a5 100644
--- a/website/views/layouts/layout.ejs
+++ b/website/views/layouts/layout.ejs
@@ -420,9 +420,9 @@
           msedge: '16',
           // msie: '11',
           safari: '10',//« earliest version to eliminate rare bug where `window.location` doesn't exist momentarily after doing a server-side redirect
-          firefox: '28',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
-          chrome: '29',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
-          opera: '17',//« earliest version to support both ES5 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          firefox: '54',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          chrome: '51',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
+          opera: '38',//« earliest version to support both ES6 (for Vue.js) and unprefixed flexbox (for Bootstrap 4)
         };
         var LATEST_SUPPORTED_VERSION_BY_BROWSER_NAME = {
           'microsoft edge': LATEST_SUPPORTED_VERSION_BY_USER_AGENT.msedge,