diff --git a/CHANGELOG.md b/CHANGELOG.md
index 60a3ffe631..29913e29ca 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 ### Features
 
+- [#6763](https://github.com/blockscout/blockscout/pull/6763) - Permanent UI dark mode
 - [#6721](https://github.com/blockscout/blockscout/pull/6721) - Implement fetching internal transactions from callTracer
 - [#6712](https://github.com/blockscout/blockscout/pull/6712) - API v2 update
 
diff --git a/apps/block_scout_web/assets/js/lib/history_chart.js b/apps/block_scout_web/assets/js/lib/history_chart.js
index 4d61cf5aa2..ef0884665c 100644
--- a/apps/block_scout_web/assets/js/lib/history_chart.js
+++ b/apps/block_scout_web/assets/js/lib/history_chart.js
@@ -18,8 +18,18 @@ const grid = {
   drawOnChartArea: false
 }
 
+function isDarkMode () {
+  // @ts-ignore
+  const permanentDarkModeEnabled = document.getElementById('permanent-dark-mode').textContent === 'true'
+  if (!permanentDarkModeEnabled) {
+    return Cookies.get('chakra-ui-color-mode') === 'dark'
+  } else {
+    return true
+  }
+}
+
 function getTxChartColor () {
-  if (Cookies.get('chakra-ui-color-mode') === 'dark') {
+  if ((isDarkMode())) {
     return sassVariables.dashboardLineColorTransactionsDarkTheme
   } else {
     return sassVariables.dashboardLineColorTransactions
@@ -27,7 +37,7 @@ function getTxChartColor () {
 }
 
 function getPriceChartColor () {
-  if (Cookies.get('chakra-ui-color-mode') === 'dark') {
+  if ((isDarkMode())) {
     return sassVariables.dashboardLineColorPriceDarkTheme
   } else {
     return sassVariables.dashboardLineColorPrice
@@ -35,7 +45,7 @@ function getPriceChartColor () {
 }
 
 function getMarketCapChartColor () {
-  if (Cookies.get('chakra-ui-color-mode') === 'dark') {
+  if ((isDarkMode())) {
     return sassVariables.dashboardLineColorMarketDarkTheme
   } else {
     return sassVariables.dashboardLineColorMarket
diff --git a/apps/block_scout_web/assets/js/pages/dark-mode-switcher.js b/apps/block_scout_web/assets/js/pages/dark-mode-switcher.js
index 37ebfafeda..0284c9e478 100644
--- a/apps/block_scout_web/assets/js/pages/dark-mode-switcher.js
+++ b/apps/block_scout_web/assets/js/pages/dark-mode-switcher.js
@@ -1,12 +1,22 @@
-import $ from 'jquery'
 import Cookies from 'js-cookie'
+const permantDarkModeEl = document.getElementById('permanent-dark-mode')
+// @ts-ignore
+const permanentDarkModeEnabled = false || (permantDarkModeEl && permantDarkModeEl.textContent === 'true')
+// @ts-ignore
+const darkModeChangerEl = document.getElementsByClassName('dark-mode-changer')[0]
 
-$('.dark-mode-changer').on('click', function () {
-  if (Cookies.get('chakra-ui-color-mode') === 'dark') {
-    Cookies.set('chakra-ui-color-mode', 'light')
-  } else {
-    Cookies.set('chakra-ui-color-mode', 'dark')
+if (permanentDarkModeEnabled) {
+  // @ts-ignore
+  darkModeChangerEl.style.display = 'none'
+}
+
+darkModeChangerEl && darkModeChangerEl.addEventListener('click', function () {
+  if (!permanentDarkModeEnabled) {
+    if (Cookies.get('chakra-ui-color-mode') === 'dark') {
+      Cookies.set('chakra-ui-color-mode', 'light')
+    } else {
+      Cookies.set('chakra-ui-color-mode', 'dark')
+    }
+    document.location.reload()
   }
-  // reload each theme switch
-  document.location.reload()
 })
diff --git a/apps/block_scout_web/assets/package-lock.json b/apps/block_scout_web/assets/package-lock.json
index 86724d2842..b4d622e1ad 100644
--- a/apps/block_scout_web/assets/package-lock.json
+++ b/apps/block_scout_web/assets/package-lock.json
@@ -95,15 +95,16 @@
         "webpack-cli": "^5.0.1"
       },
       "engines": {
-        "node": "16.x",
+        "node": "18.x",
         "npm": "8.x"
       }
     },
     "../../../deps/phoenix": {
-      "version": "0.0.1"
+      "version": "1.5.13",
+      "license": "MIT"
     },
     "../../../deps/phoenix_html": {
-      "version": "0.0.1"
+      "version": "3.0.4"
     },
     "node_modules/@amplitude/analytics-browser": {
       "version": "1.6.8",
diff --git a/apps/block_scout_web/assets/package.json b/apps/block_scout_web/assets/package.json
index f110bffd26..57dfbf8d14 100644
--- a/apps/block_scout_web/assets/package.json
+++ b/apps/block_scout_web/assets/package.json
@@ -8,7 +8,7 @@
   "author": "Blockscout",
   "license": "GPL-3.0",
   "engines": {
-    "node": "16.x",
+    "node": "18.x",
     "npm": "8.x"
   },
   "scripts": {
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/csv_export/index.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/csv_export/index.html.eex
index d1b5b394bd..07a1ee0d13 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/csv_export/index.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/csv_export/index.html.eex
@@ -32,7 +32,14 @@
       if (reCaptchaClientKey) {
         widgetId1 = grecaptcha.render('recaptcha', {
           'sitekey': reCaptchaClientKey,
-          'theme': getCookie('chakra-ui-color-mode'),
+          'theme': function () {
+            const permanentDarkModeEnabled = document.getElementById('permanent-dark-mode').textContent === 'true'
+            if (permanentDarkModeEnabled) {
+              return 'dark'
+            } else {
+              return getCookie('chakra-ui-color-mode')
+            }
+          },
           'callback': function () {
             document.getElementById('export-csv-button').disabled = false
           }
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/layout/app.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/layout/app.html.eex
index 60c0754acf..d717e07099 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/layout/app.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/layout/app.html.eex
@@ -52,59 +52,6 @@
   </head>
 
   <body>
-    <script defer data-cfasync="false">
-      function getCookie(name) {
-        const value = `; ${document.cookie}`;
-        const parts = value.split(`; ${name}=`);
-        if (parts.length === 2) return parts.pop().split(';').shift();
-      }
-
-      function applyDarkMode() {
-        if (getCookie('chakra-ui-color-mode') === "dark") {
-          document.body.className += " " + "dark-theme-applied";
-          document.body.style.backgroundColor = "#1c1d31";
-        }
-      }
-      window.onload = applyDarkMode()
-    </script>
-    <script defer data-cfasync="false">
-      if (getCookie('chakra-ui-color-mode') === "dark") {
-        if (document.getElementById("top-navbar")) {
-          document.getElementById("top-navbar").style.backgroundColor = "#282945";
-        }
-        if (document.getElementById("navbar-logo")) {
-          document.getElementById("navbar-logo").style.filter = "brightness(0) invert(1)";
-        }
-        let modeChanger = document.getElementById("dark-mode-changer");
-        if (modeChanger) {
-          modeChanger.className += " " + "dark-mode-changer--dark";
-        }
-      }
-    </script>
-    <script defer data-cfasync="false">
-      if (getCookie('chakra-ui-color-mode') === "dark") {
-        const search = document.getElementById("main-search-autocomplete")
-        const searchMobile = document.getElementById("main-search-autocomplete-mobile")
-            if (search && search.style) {
-          search.style.backgroundColor = "#22223a";
-              search.style.borderColor = "#22223a";
-        }
-        if (searchMobile && searchMobile.style) {
-          searchMobile.style.backgroundColor = "#22223a";
-          searchMobile.style.borderColor = "#22223a";
-        }
-      }
-    </script>
-    <% raw_dark_forest_addresses_0_4 = CustomContractsHelpers.get_raw_custom_addresses_list(:dark_forest_addresses) || "" %>
-    <% raw_dark_forest_addresses_0_5 = CustomContractsHelpers.get_raw_custom_addresses_list(:dark_forest_addresses_v_0_5) || "" %>
-    <% raw_dark_forest_addresses_0_6 = CustomContractsHelpers.get_raw_custom_addresses_list(:dark_forest_addresses_v_0_6) || "" %>
-    <% raw_dark_forest_addresses_0_6_r2 = CustomContractsHelpers.get_raw_custom_addresses_list(:dark_forest_addresses_v_0_6_r2) || "" %>
-    <% raw_dark_forest_addresses = raw_dark_forest_addresses_0_4 %>
-    <% raw_dark_forest_addresses = if raw_dark_forest_addresses_0_5 !== "", do: raw_dark_forest_addresses <> "," <> raw_dark_forest_addresses_0_5, else: raw_dark_forest_addresses %>
-    <% raw_dark_forest_addresses = if raw_dark_forest_addresses_0_6 !== "", do: raw_dark_forest_addresses <> "," <> raw_dark_forest_addresses_0_6, else: raw_dark_forest_addresses %>
-    <% raw_dark_forest_addresses = if raw_dark_forest_addresses_0_6_r2 !== "", do: raw_dark_forest_addresses <> "," <> raw_dark_forest_addresses_0_6_r2, else: raw_dark_forest_addresses %>
-
-    <% raw_circles_addresses = CustomContractsHelpers.get_raw_custom_addresses_list(:circles_addresses) %>
     <%= cond do %>
       <% (
         @view_module == Elixir.BlockScoutWeb.TransactionInternalTransactionView ||
@@ -117,10 +64,6 @@
         <% {:ok, created_from_address} = if @transaction.to_address_hash, do: Chain.hash_to_address(@transaction.to_address_hash), else: {:ok, nil} %>
         <% created_from_address_hash_str = if from_address_hash(created_from_address), do: "0x" <> Base.encode16(from_address_hash(created_from_address).bytes, case: :lower), else: nil %>
         <script>
-          function applyCustomMode() {
-            applyCustomTheme("<%= raw_dark_forest_addresses %>", "dark-forest-theme-applied")
-            applyCustomTheme("<%= raw_circles_addresses %>", "circles-theme-applied")
-          }
           function applyCustomTheme(contractAddressHashesRaw, customClass) {
             if (contractAddressHashesRaw !== "") {
               const contractAddressHashes = contractAddressHashesRaw.split(',').map(hash => hash.toLowerCase())
@@ -158,19 +101,15 @@
       ) -> %>
         <% created_from_address = if @address && from_address_hash(@address), do: "0x" <> Base.encode16(from_address_hash(@address).bytes, case: :lower), else: nil %>
         <script>
-          function applyCustomMode() {
-            applyCustomTheme("<%= raw_dark_forest_addresses %>", "dark-forest-theme-applied")
-            applyCustomTheme("<%= raw_circles_addresses %>", "circles-theme-applied")
-          }
           function applyCustomTheme(contractAddressHashesRaw, customClass) {
             if (contractAddressHashesRaw !== "") {
               const contractAddressHashes = contractAddressHashesRaw.split(',').map(hash => hash.toLowerCase())
-              const created_from_address = "<%= created_from_address %>"
+              const createdFromAddress = "<%= created_from_address %>"
               contractAddressHashes.forEach(contractAddressHash => {
                 if (window.location.pathname.toLowerCase().includes(contractAddressHash)) {
                   document.body.className += " " + customClass;
                   return;
-                } else if (contractAddressHash == created_from_address) {
+                } else if (contractAddressHash == createdFromAddress) {
                   document.body.className += " " + customClass;
                   return;
                 }
@@ -178,7 +117,6 @@
             }
           }
 
-          window.onload = applyCustomMode()
         </script>
       <% (
         @view_module == Elixir.BlockScoutWeb.Tokens.TransferView ||
@@ -191,10 +129,6 @@
         <% {:ok, created_from_address} = if @token && @token.contract_address_hash, do: Chain.hash_to_address(@token.contract_address_hash), else: {:ok, nil} %>
         <% created_from_address_hash = if from_address_hash(created_from_address), do: "0x" <> Base.encode16(from_address_hash(created_from_address).bytes, case: :lower), else: nil %>
         <script>
-          function applyCustomMode() {
-            applyCustomTheme("<%= raw_dark_forest_addresses %>", "dark-forest-theme-applied")
-            applyCustomTheme("<%= raw_circles_addresses %>", "circles-theme-applied")
-          }
           function applyCustomTheme(contractAddressHashesRaw, customClass) {
             if (contractAddressHashesRaw !== "") {
               const contractAddressHashes = contractAddressHashesRaw.split(',').map(hash => hash.toLowerCase())
@@ -217,6 +151,7 @@
         <%= nil %>
     <% end %>
     <div class="layout-container">
+      <div id="permanent-dark-mode" class="d-none" ><%= Application.get_env(:block_scout_web, :permanent_dark_mode_enabled) %></div>
       <% show_maintenance_alert = Application.get_env(:block_scout_web, BlockScoutWeb.Chain)[:show_maintenance_alert] %>
       <%= if show_maintenance_alert do %>
         <div class="alert alert-warning text-center mb-0 p-3" data-selector="indexed-status">
@@ -310,5 +245,53 @@
     <%= if @view_module in [Elixir.BlockScoutWeb.AddressContractVerificationViaMultiPartFilesView, Elixir.BlockScoutWeb.AddressContractVerificationViaJsonView, Elixir.BlockScoutWeb.AddressContractVerificationViaStandardJsonInputView] do %>
       <script defer data-cfasync="false" src="<%= static_path(@conn, "/js/dropzone.js") %>"></script>
     <% end %>
+    <script defer data-cfasync="false">
+      function getCookie(name) {
+        const value = `; ${document.cookie}`;
+        const parts = value.split(`; ${name}=`);
+        if (parts.length === 2) return parts.pop().split(';').shift();
+      }
+
+      function isDarkMode() {
+        const permanentDarkModeEnabled = document.getElementById('permanent-dark-mode').textContent === 'true'
+        if (!permanentDarkModeEnabled) {
+          return getCookie('chakra-ui-color-mode') === 'dark'
+        } else {
+          return true
+        }
+      }
+
+      function applyDarkMode() {
+        if (isDarkMode()) {
+          document.body.className += " " + "dark-theme-applied";
+          document.body.style.backgroundColor = "#1c1d31";
+        }
+      }
+      window.onload = applyDarkMode()
+
+      if (isDarkMode()) {
+        if (document.getElementById("top-navbar")) {
+          document.getElementById("top-navbar").style.backgroundColor = "#282945";
+        }
+        if (document.getElementById("navbar-logo")) {
+          document.getElementById("navbar-logo").style.filter = "brightness(0) invert(1)";
+        }
+        let modeChanger = document.getElementById("dark-mode-changer");
+        if (modeChanger) {
+          modeChanger.className += " " + "dark-mode-changer--dark";
+        }
+
+        const search = document.getElementById("main-search-autocomplete")
+        const searchMobile = document.getElementById("main-search-autocomplete-mobile")
+            if (search && search.style) {
+          search.style.backgroundColor = "#22223a";
+              search.style.borderColor = "#22223a";
+        }
+        if (searchMobile && searchMobile.style) {
+          searchMobile.style.backgroundColor = "#22223a";
+          searchMobile.style.borderColor = "#22223a";
+        }
+      }
+    </script>
   </body>
 </html>
diff --git a/apps/explorer/package.json b/apps/explorer/package.json
index 3c5c000959..0f75b6e96a 100644
--- a/apps/explorer/package.json
+++ b/apps/explorer/package.json
@@ -8,7 +8,7 @@
   "author": "Blockscout",
   "license": "GPL-3.0",
   "engines": {
-    "node": "16.x",
+    "node": "18.x",
     "npm": "8.x"
   },
   "scripts": {},
diff --git a/config/runtime.exs b/config/runtime.exs
index b6b71a52e9..70d8d389d1 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -100,7 +100,8 @@ config :block_scout_web,
   new_tags: System.get_env("NEW_TAGS"),
   chain_id: System.get_env("CHAIN_ID"),
   json_rpc: System.get_env("JSON_RPC"),
-  verification_max_libraries: verification_max_libraries
+  verification_max_libraries: verification_max_libraries,
+  permanent_dark_mode_enabled: System.get_env("PERMANENT_DARK_MODE_ENABLED", "false") == "true"
 
 default_api_rate_limit = 50
 default_api_rate_limit_str = Integer.to_string(default_api_rate_limit)