diff --git a/packages/config/package.json b/packages/config/package.json
index 6768f2caab..e715f0a4a9 100644
--- a/packages/config/package.json
+++ b/packages/config/package.json
@@ -10,7 +10,7 @@
     "index.d.ts"
   ],
   "dependencies": {
-    "@nuxt/ufo": "^0.0.3",
+    "@nuxt/ufo": "^0.1.0",
     "@nuxt/utils": "2.14.10",
     "consola": "^2.15.0",
     "create-require": "^1.1.1",
diff --git a/packages/config/src/options.js b/packages/config/src/options.js
index f1701fad26..29424d084d 100644
--- a/packages/config/src/options.js
+++ b/packages/config/src/options.js
@@ -7,7 +7,7 @@ import uniq from 'lodash/uniq'
 import consola from 'consola'
 import destr from 'destr'
 import { TARGETS, MODES, guardDir, isNonEmptyString, isPureObject, isUrl, getMainModule, urlJoin, getPKG } from '@nuxt/utils'
-import { normalizeURL } from '@nuxt/ufo'
+import { normalizeURL, withTrailingSlash } from '@nuxt/ufo'
 import { defaultNuxtConfigFile, getDefaultNuxtConfig } from './config'
 
 export function getNuxtConfig (_options) {
@@ -124,10 +124,7 @@ export function getNuxtConfig (_options) {
   defaultsDeep(options, modePreset || options.modes[MODES.universal])
 
   // Sanitize router.base
-  if (!/\/$/.test(options.router.base)) {
-    options.router.base += '/'
-  }
-  options.router.base = normalizeURL(options.router.base)
+  options.router.base = withTrailingSlash(normalizeURL(options.router.base))
 
   // Legacy support for export
   if (options.export) {
diff --git a/packages/utils/package.json b/packages/utils/package.json
index 1be6b05132..6cfd0c0c85 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -8,7 +8,7 @@
     "dist"
   ],
   "dependencies": {
-    "@nuxt/ufo": "^0.0.3",
+    "@nuxt/ufo": "^0.1.0",
     "consola": "^2.15.0",
     "fs-extra": "^8.1.0",
     "hash-sum": "^2.0.0",
diff --git a/packages/utils/src/route.js b/packages/utils/src/route.js
index d09eea26db..abd5868222 100644
--- a/packages/utils/src/route.js
+++ b/packages/utils/src/route.js
@@ -201,7 +201,7 @@ export const createRoutes = function createRoutes ({
       } else if (key === 'index' && i + 1 === keys.length) {
         route.path += i > 0 ? '' : '/'
       } else {
-        route.path += normalizeURL(getRoutePathExtension(key))
+        route.path += '/' + normalizeURL(getRoutePathExtension(key))
         if (key.startsWith('_') && key.length > 1) {
           route.path += '?'
         }
diff --git a/packages/vue-app/package.json b/packages/vue-app/package.json
index 76682bcf16..786dd8ce66 100644
--- a/packages/vue-app/package.json
+++ b/packages/vue-app/package.json
@@ -13,7 +13,7 @@
     "index.d.ts"
   ],
   "dependencies": {
-    "@nuxt/ufo": "^0.0.3",
+    "@nuxt/ufo": "^0.1.0",
     "node-fetch": "^2.6.1",
     "unfetch": "^4.2.0",
     "vue": "^2.6.12",
diff --git a/packages/webpack/package.json b/packages/webpack/package.json
index ad219002e6..1ebb18dd54 100644
--- a/packages/webpack/package.json
+++ b/packages/webpack/package.json
@@ -43,6 +43,7 @@
     "thread-loader": "^2.1.3",
     "time-fix-plugin": "^2.0.7",
     "url-loader": "^2.3.0",
+    "url-polyfill": "^1.1.12",
     "vue-loader": "^15.9.5",
     "webpack": "^4.44.2",
     "webpack-bundle-analyzer": "^3.9.0",
diff --git a/packages/webpack/src/config/client.js b/packages/webpack/src/config/client.js
index 3a3d7ee72d..7916fdd60b 100644
--- a/packages/webpack/src/config/client.js
+++ b/packages/webpack/src/config/client.js
@@ -63,7 +63,7 @@ export default class WebpackClientConfig extends WebpackBaseConfig {
       cacheGroups.commons === undefined
     ) {
       cacheGroups.commons = {
-        test: /node_modules[\\/](vue|vue-loader|vue-router|vuex|vue-meta|core-js|@babel\/runtime|axios|webpack|setimmediate|timers-browserify|process|regenerator-runtime|cookie|js-cookie|is-buffer|dotprop|nuxt\.js)[\\/]/,
+        test: /node_modules[\\/](vue|vue-loader|vue-router|vuex|vue-meta|core-js|@babel\/runtime|axios|webpack|setimmediate|timers-browserify|process|regenerator-runtime|cookie|js-cookie|is-buffer|dotprop|url-polyfill|nuxt\.js)[\\/]/,
         chunks: 'all',
         name: true,
         priority: 10
@@ -205,6 +205,11 @@ export default class WebpackClientConfig extends WebpackBaseConfig {
       )
     }
 
+    // Add URL polyfill for IE11 support with ufo
+    if (!this.isModern && !this.isServer) {
+      config.entry.app.unshift(require.resolve('url-polyfill/url-polyfill.min.js'))
+    }
+
     // Add friendly error plugin
     if (this.dev && !quiet && friendlyErrors) {
       config.plugins.push(
diff --git a/test/dev/async-config.size-limit.test.js b/test/dev/async-config.size-limit.test.js
index 52977e1c8b..cf7adb36be 100644
--- a/test/dev/async-config.size-limit.test.js
+++ b/test/dev/async-config.size-limit.test.js
@@ -20,20 +20,20 @@ describe('nuxt basic resources size limit', () => {
   it('should stay within the size limit range in legacy mode', async () => {
     const legacyResourcesSize = await getResourcesSize(distDir, 'client', { gzip: true, brotli: true })
 
-    const LEGACY_JS_RESOURCES_KB_SIZE = 201
+    const LEGACY_JS_RESOURCES_KB_SIZE = 217
     expect(legacyResourcesSize.uncompressed).toBeWithinSize(LEGACY_JS_RESOURCES_KB_SIZE)
 
     const LEGACY_JS_RESOURCES_GZIP_KB_SIZE = 70
     expect(legacyResourcesSize.gzip).toBeWithinSize(LEGACY_JS_RESOURCES_GZIP_KB_SIZE)
 
-    const LEGACY_JS_RESOURCES_BROTLI_KB_SIZE = 60
+    const LEGACY_JS_RESOURCES_BROTLI_KB_SIZE = 64
     expect(legacyResourcesSize.brotli).toBeWithinSize(LEGACY_JS_RESOURCES_BROTLI_KB_SIZE)
   })
 
   it('should stay within the size limit range in modern mode', async () => {
     const modernResourcesSize = await getResourcesSize(distDir, 'modern', { gzip: true, brotli: true })
 
-    const MODERN_JS_RESOURCES_KB_SIZE = 172
+    const MODERN_JS_RESOURCES_KB_SIZE = 180
     expect(modernResourcesSize.uncompressed).toBeWithinSize(MODERN_JS_RESOURCES_KB_SIZE)
 
     const MODERN_JS_RESOURCES_GZIP_KB_SIZE = 60
diff --git a/yarn.lock b/yarn.lock
index 741b2a6246..4d3efd4554 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1955,10 +1955,10 @@
     rc9 "^1.2.0"
     std-env "^2.2.1"
 
-"@nuxt/ufo@^0.0.3":
-  version "0.0.3"
-  resolved "https://registry.npmjs.org/@nuxt/ufo/-/ufo-0.0.3.tgz#7673a54b81c020e7aea3a9e01e09a58c494a1eca"
-  integrity sha512-LQkuVafVNB9+ggRF7443AX1V1rEWRs32Frk7F2qnRLf8j/SzRzxEZ99jiZqxVho72zU7NcWQ6Jy62m4fkZC6Wg==
+"@nuxt/ufo@^0.1.0":
+  version "0.1.0"
+  resolved "https://registry.npmjs.org/@nuxt/ufo/-/ufo-0.1.0.tgz#4943741c4300b73e4f1de09cad684ed4e9235502"
+  integrity sha512-7az26cl4TaNejTFlgwcGRIGPFH6tD8dLh1t+Q+BWIM8UQqqV9o2DH9yKcVlboP+LdocLBUC+OTOiZc0RSZh0bA==
 
 "@nuxtjs/eslint-config@^5.0.0":
   version "5.0.0"
@@ -13205,6 +13205,11 @@ url-loader@^2.3.0:
     mime "^2.4.4"
     schema-utils "^2.5.0"
 
+url-polyfill@^1.1.12:
+  version "1.1.12"
+  resolved "https://registry.npmjs.org/url-polyfill/-/url-polyfill-1.1.12.tgz#6cdaa17f6b022841b3aec0bf8dbd87ac0cd33331"
+  integrity sha512-mYFmBHCapZjtcNHW0MDq9967t+z4Dmg5CJ0KqysK3+ZbyoNOWQHksGCTWwDhxGXllkWlOc10Xfko6v4a3ucM6A==
+
 url@^0.11.0:
   version "0.11.0"
   resolved "https://registry.npmjs.org/url/-/url-0.11.0.tgz#3838e97cfc60521eb73c525a8e55bfdd9e2e28f1"