diff --git a/.eslintrc.cjs b/.eslintrc.cjs
index 6b562e5bf..e829eaa1f 100644
--- a/.eslintrc.cjs
+++ b/.eslintrc.cjs
@@ -54,12 +54,12 @@ module.exports = {
       },
     },
     polyfills: [
-      'es:all',
-      'fetch',
-      'IntersectionObserver',
-      'Promise',
-      'URL',
-      'URLSearchParams',
+      'es:all', // core-js
+      'IntersectionObserver', // npm:intersection-observer
+      'Promise', // core-js
+      'ResizeObserver', // npm:resize-observer-polyfill
+      'URL', // core-js
+      'URLSearchParams', // core-js
     ],
   },
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7e0e765d6..cd6a7a28b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Admin: redirect the homepage to any URL.
 - Compatibility: added compatibility with Friendica.
 - Posts: bot badge on statuses from bot accounts.
+- Compatibility: improved browser support for older browsers.
 
 ### Changed
 - Chats: improved display of media attachments.
diff --git a/app/soapbox/components/autosuggest-textarea.tsx b/app/soapbox/components/autosuggest-textarea.tsx
index 1cdc7fa06..9736e5950 100644
--- a/app/soapbox/components/autosuggest-textarea.tsx
+++ b/app/soapbox/components/autosuggest-textarea.tsx
@@ -157,7 +157,8 @@ class AutosuggestTextarea extends ImmutablePureComponent<IAutosuggesteTextarea>
     if (lastTokenUpdated && !valueUpdated) {
       return false;
     } else {
-      return super.shouldComponentUpdate!(nextProps, nextState, undefined);
+      // https://stackoverflow.com/a/35962835
+      return super.shouldComponentUpdate!.bind(this)(nextProps, nextState, undefined);
     }
   }
 
diff --git a/app/soapbox/components/modal-root.tsx b/app/soapbox/components/modal-root.tsx
index 6681072cd..8abc27eac 100644
--- a/app/soapbox/components/modal-root.tsx
+++ b/app/soapbox/components/modal-root.tsx
@@ -248,10 +248,9 @@ const ModalRoot: React.FC<IModalRoot> = ({ children, onCancel, onClose, type })
       <div
         role='dialog'
         className={classNames({
-          'my-2 mx-auto relative pointer-events-none flex items-center': true,
+          'my-2 mx-auto relative pointer-events-none flex items-center min-h-[calc(100%-3.5rem)]': true,
           'p-4 md:p-0': type !== 'MEDIA',
         })}
-        style={{ minHeight: 'calc(100% - 3.5rem)' }}
       >
         {children}
       </div>
diff --git a/app/soapbox/features/ads/components/ad.tsx b/app/soapbox/features/ads/components/ad.tsx
index c42eb3db5..75e649784 100644
--- a/app/soapbox/features/ads/components/ad.tsx
+++ b/app/soapbox/features/ads/components/ad.tsx
@@ -1,4 +1,5 @@
 import { useQuery, useQueryClient } from '@tanstack/react-query';
+import axios from 'axios';
 import React, { useState, useEffect, useRef } from 'react';
 import { FormattedMessage } from 'react-intl';
 
@@ -24,9 +25,9 @@ const Ad: React.FC<IAd> = ({ ad }) => {
 
   // Fetch the impression URL (if any) upon displaying the ad.
   // Don't fetch it more than once.
-  useQuery(['ads', 'impression', ad.impression], () => {
+  useQuery(['ads', 'impression', ad.impression], async () => {
     if (ad.impression) {
-      return fetch(ad.impression);
+      return await axios.get(ad.impression);
     }
   }, { cacheTime: Infinity, staleTime: Infinity });
 
diff --git a/app/soapbox/features/ads/providers/rumble.ts b/app/soapbox/features/ads/providers/rumble.ts
index bc86e8686..68a006e00 100644
--- a/app/soapbox/features/ads/providers/rumble.ts
+++ b/app/soapbox/features/ads/providers/rumble.ts
@@ -1,3 +1,5 @@
+import axios from 'axios';
+
 import { getSettings } from 'soapbox/actions/settings';
 import { getSoapboxConfig } from 'soapbox/actions/soapbox';
 import { normalizeAd, normalizeCard } from 'soapbox/normalizers';
@@ -28,14 +30,13 @@ const RumbleAdProvider: AdProvider = {
     const endpoint = soapboxConfig.extensions.getIn(['ads', 'endpoint']) as string | undefined;
 
     if (endpoint) {
-      const response = await fetch(endpoint, {
-        headers: {
-          'Accept-Language': settings.get('locale', '*') as string,
-        },
-      });
-
-      if (response.ok) {
-        const data = await response.json() as RumbleApiResponse;
+      try {
+        const { data } = await axios.get<RumbleApiResponse>(endpoint, {
+          headers: {
+            'Accept-Language': settings.get('locale', '*') as string,
+          },
+        });
+
         return data.ads.map(item => normalizeAd({
           impression: item.impression,
           card: normalizeCard({
@@ -45,6 +46,8 @@ const RumbleAdProvider: AdProvider = {
           }),
           expires_at: new Date(item.expires * 1000),
         }));
+      } catch (e) {
+        // do nothing
       }
     }
 
diff --git a/app/soapbox/features/ads/providers/truth.ts b/app/soapbox/features/ads/providers/truth.ts
index 92f2e99f8..a9af3c0d7 100644
--- a/app/soapbox/features/ads/providers/truth.ts
+++ b/app/soapbox/features/ads/providers/truth.ts
@@ -1,3 +1,5 @@
+import axios from 'axios';
+
 import { getSettings } from 'soapbox/actions/settings';
 import { normalizeCard } from 'soapbox/normalizers';
 
@@ -18,18 +20,19 @@ const TruthAdProvider: AdProvider = {
     const state = getState();
     const settings = getSettings(state);
 
-    const response = await fetch('/api/v2/truth/ads?device=desktop', {
-      headers: {
-        'Accept-Language': settings.get('locale', '*') as string,
-      },
-    });
+    try {
+      const { data } = await axios.get<TruthAd[]>('/api/v2/truth/ads?device=desktop', {
+        headers: {
+          'Accept-Language': settings.get('locale', '*') as string,
+        },
+      });
 
-    if (response.ok) {
-      const data = await response.json() as TruthAd[];
       return data.map(item => ({
         ...item,
         card: normalizeCard(item.card),
       }));
+    } catch (e) {
+      // do nothing
     }
 
     return [];
diff --git a/app/soapbox/features/ui/__tests__/index.test.tsx b/app/soapbox/features/ui/__tests__/index.test.tsx
index f3e32f5f7..0a55f3ca5 100644
--- a/app/soapbox/features/ui/__tests__/index.test.tsx
+++ b/app/soapbox/features/ui/__tests__/index.test.tsx
@@ -50,7 +50,7 @@ describe('<UI />', () => {
         await waitFor(() => {
           expect(screen.getByTestId('cta-banner')).toHaveTextContent('Sign up now to discuss');
         }, {
-          timeout: 2000,
+          timeout: 5000,
         });
       });
     });
diff --git a/app/soapbox/hooks/useDimensions.ts b/app/soapbox/hooks/useDimensions.ts
index b08c05f4e..ae0321e2b 100644
--- a/app/soapbox/hooks/useDimensions.ts
+++ b/app/soapbox/hooks/useDimensions.ts
@@ -1,5 +1,4 @@
 import { useEffect, useMemo, useState } from 'react';
-import ResizeObserver from 'resize-observer-polyfill';
 
 type UseDimensionsRect = { width: number, height: number };
 type UseDimensionsResult = [Element | null, any, any]
diff --git a/app/soapbox/main.tsx b/app/soapbox/main.tsx
index 9fc753990..f5cf9f0f5 100644
--- a/app/soapbox/main.tsx
+++ b/app/soapbox/main.tsx
@@ -1,3 +1,5 @@
+import './polyfills';
+
 import * as OfflinePluginRuntime from '@lcdp/offline-plugin/runtime';
 import React from 'react';
 import { createRoot } from 'react-dom/client';
diff --git a/app/soapbox/polyfills.ts b/app/soapbox/polyfills.ts
new file mode 100644
index 000000000..21947e4fe
--- /dev/null
+++ b/app/soapbox/polyfills.ts
@@ -0,0 +1,8 @@
+import 'intersection-observer';
+import ResizeObserver from 'resize-observer-polyfill';
+
+// Needed by Virtuoso
+// https://github.com/petyosi/react-virtuoso#browser-support
+if (!window.ResizeObserver) {
+  window.ResizeObserver = ResizeObserver;
+}
\ No newline at end of file
diff --git a/app/soapbox/service-worker/web-push-notifications.ts b/app/soapbox/service-worker/web-push-notifications.ts
index 872d255c6..8088ca902 100644
--- a/app/soapbox/service-worker/web-push-notifications.ts
+++ b/app/soapbox/service-worker/web-push-notifications.ts
@@ -1,3 +1,4 @@
+/* eslint-disable compat/compat */
 import IntlMessageFormat from 'intl-messageformat';
 import 'intl-pluralrules';
 import unescape from 'lodash/unescape';
diff --git a/app/styles/components/modal.scss b/app/styles/components/modal.scss
index 34e375acc..ed9a9912c 100644
--- a/app/styles/components/modal.scss
+++ b/app/styles/components/modal.scss
@@ -7,8 +7,8 @@
 }
 
 .media-modal {
-  width: 100%;
-  height: 100%;
+  // https://stackoverflow.com/a/8468131
+  @apply w-full h-full absolute inset-0;
 
   .audio-player.detailed,
   .extended-video-player {
diff --git a/babel.config.cjs b/babel.config.cjs
index 2d684880b..93b9db3e4 100644
--- a/babel.config.cjs
+++ b/babel.config.cjs
@@ -5,7 +5,7 @@ module.exports = (api) => {
     debug: false,
     modules: false,
     useBuiltIns: 'usage',
-    corejs: '3.15',
+    corejs: '3.27',
   };
 
   const config = {
diff --git a/package.json b/package.json
index 06f47abdc..e48b340ea 100644
--- a/package.json
+++ b/package.json
@@ -31,9 +31,9 @@
   },
   "license": "AGPL-3.0-or-later",
   "browserslist": [
-    "> 0.5%",
+    "> 0.2%",
     "last 2 versions",
-    "not IE 11",
+    "last 4 years",
     "not dead"
   ],
   "dependencies": {
@@ -111,7 +111,7 @@
     "cheerio": "^1.0.0-rc.10",
     "clsx": "^1.2.1",
     "copy-webpack-plugin": "^11.0.0",
-    "core-js": "^3.15.2",
+    "core-js": "^3.27.2",
     "cryptocurrency-icons": "^0.18.1",
     "css-loader": "^6.7.1",
     "cssnano": "^5.1.10",
@@ -127,6 +127,7 @@
     "http-link-header": "^1.0.2",
     "immutable": "^4.2.1",
     "imports-loader": "^4.0.0",
+    "intersection-observer": "^0.12.2",
     "intl-messageformat": "9.13.0",
     "intl-messageformat-parser": "^6.0.0",
     "intl-pluralrules": "^1.3.1",
diff --git a/webpack/production.ts b/webpack/production.ts
index 78845be37..810a943ef 100644
--- a/webpack/production.ts
+++ b/webpack/production.ts
@@ -50,7 +50,6 @@ const configuration: Configuration = {
         ],
         optional: [
           '**/locale_*.js', // don't fetch every locale; the user only needs one
-          '**/*_polyfills-*.js', // the user may not need polyfills
           '**/*.chunk.js', // only cache chunks when needed
           '**/*.chunk.css',
           '**/*.woff2', // the user may have system-fonts enabled
@@ -138,6 +137,7 @@ const configuration: Configuration = {
             '/apple-touch-icon.png',
             '/browserconfig.xml',
             '/robots.txt',
+            '/report.html',
           ];
 
           if (backendRoutes.some(path => pathname.startsWith(path)) || pathname.endsWith('/embed')) {
diff --git a/yarn.lock b/yarn.lock
index a1fb69a9b..916d4ccda 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4498,16 +4498,16 @@ core-js-pure@^3.23.3:
   resolved "https://registry.yarnpkg.com/core-js-pure/-/core-js-pure-3.27.1.tgz#ede4a6b8440585c7190062757069c01d37a19dca"
   integrity sha512-BS2NHgwwUppfeoqOXqi08mUqS5FiZpuRuJJpKsaME7kJz0xxuk0xkhDdfMIlP/zLa80krBqss1LtD7f889heAw==
 
-core-js@^3.15.2:
-  version "3.18.0"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.18.0.tgz#9af3f4a6df9ba3428a3fb1b171f1503b3f40cc49"
-  integrity sha512-WJeQqq6jOYgVgg4NrXKL0KLQhi0CT4ZOCvFL+3CQ5o7I6J8HkT5wd53EadMfqTDp1so/MT1J+w2ujhWcCJtN7w==
-
 core-js@^3.16.2:
   version "3.23.5"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.23.5.tgz#1f82b0de5eece800827a2f59d597509c67650475"
   integrity sha512-7Vh11tujtAZy82da4duVreQysIoO2EvVrur7y6IzZkH1IHPSekuDi8Vuw1+YKjkbfWLRD7Nc9ICQ/sIUDutcyg==
 
+core-js@^3.27.2:
+  version "3.27.2"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.27.2.tgz#85b35453a424abdcacb97474797815f4d62ebbf7"
+  integrity sha512-9ashVQskuh5AZEZ1JdQWp1GqSoC1e1G87MzRqg2gIfVAQ7Qn9K+uFj8EcniUFA4P2NLZfV+TOlX1SzoKfo+s7w==
+
 core-js@^3.8.2:
   version "3.23.1"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.23.1.tgz#9f9a9255115f62c512db56d567f636da32ca0b78"
@@ -6653,6 +6653,11 @@ intersection-observer@^0.12.0:
   resolved "https://registry.yarnpkg.com/intersection-observer/-/intersection-observer-0.12.0.tgz#6c84628f67ce8698e5f9ccf857d97718745837aa"
   integrity sha512-2Vkz8z46Dv401zTWudDGwO7KiGHNDkMv417T5ItcNYfmvHR/1qCTVBO9vwH8zZmQ0WkA/1ARwpysR9bsnop4NQ==
 
+intersection-observer@^0.12.2:
+  version "0.12.2"
+  resolved "https://registry.yarnpkg.com/intersection-observer/-/intersection-observer-0.12.2.tgz#4a45349cc0cd91916682b1f44c28d7ec737dc375"
+  integrity sha512-7m1vEcPCxXYI8HqnL8CKI6siDyD+eIWSwgB3DZA+ZTogxk9I4CDnj4wilt9x/+/QbHI4YG5YZNmC6458/e9Ktg==
+
 intl-messageformat-parser@6.1.2:
   version "6.1.2"
   resolved "https://registry.yarnpkg.com/intl-messageformat-parser/-/intl-messageformat-parser-6.1.2.tgz#28c65f3689f538e66c7cf628881548d6a82ff3c2"