diff --git a/README.md b/README.md
index a09d65535e7..b54194a7221 100644
--- a/README.md
+++ b/README.md
@@ -183,9 +183,9 @@ Add the bridge name to `whitelist.txt`:
 
 ### How to enable debug mode
 
-Create a file named `DEBUG`:
+Set in `config.ini.php`:
 
-    touch DEBUG
+    enable_debug_mode = true
 
 Learn more in [debug mode](https://rss-bridge.github.io/rss-bridge/For_Developers/Debug_mode.html).
 
diff --git a/actions/DisplayAction.php b/actions/DisplayAction.php
index 3a262674380..c71be5dd11f 100644
--- a/actions/DisplayAction.php
+++ b/actions/DisplayAction.php
@@ -107,7 +107,7 @@ public function execute(array $request)
             && (time() - $cache_timeout < $mtime)
             && !Debug::isEnabled()
         ) {
-            // At this point we found the feed in the cache
+            // At this point we found the feed in the cache and debug mode is disabled
 
             if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
                 // The client wants to know if the feed has changed since its last check
@@ -118,7 +118,7 @@ public function execute(array $request)
                 }
             }
 
-            // Fetch the cached feed from the cache and prepare it
+            // Load the feed from cache and prepare it
             $cached = $cache->loadData();
             if (isset($cached['items']) && isset($cached['extraInfos'])) {
                 foreach ($cached['items'] as $item) {
@@ -127,7 +127,7 @@ public function execute(array $request)
                 $infos = $cached['extraInfos'];
             }
         } else {
-            // At this point we did NOT find the feed in the cache. So invoke the bridge!
+            // At this point we did NOT find the feed in the cache or debug mode is enabled.
             try {
                 $bridge->setDatas($bridge_params);
                 $bridge->collectData();
@@ -200,7 +200,7 @@ private function createFeedItemFromException($e, BridgeInterface $bridge): FeedI
         $item->setURI(get_current_url());
         $item->setTimestamp(time());
 
-        // Create a item identifier for feed readers e.g. "staysafetv twitch videos_19389"
+        // Create an item identifier for feed readers e.g. "staysafetv twitch videos_19389"
         $item->setUid($bridge->getName() . '_' . $uniqueIdentifier);
 
         $content = render_template(__DIR__ . '/../templates/bridge-error.html.php', [
diff --git a/actions/FrontpageAction.php b/actions/FrontpageAction.php
index f015062f55b..f7ba56e65b0 100644
--- a/actions/FrontpageAction.php
+++ b/actions/FrontpageAction.php
@@ -24,6 +24,7 @@ public function execute(array $request)
         }
 
         return render(__DIR__ . '/../templates/frontpage.html.php', [
+            'messages' => [],
             'admin_email' => Configuration::getConfig('admin', 'email'),
             'admin_telegram' => Configuration::getConfig('admin', 'telegram'),
             'bridges' => $body,
diff --git a/bridges/SchweinfurtBuergerinformationenBridge.php b/bridges/SchweinfurtBuergerinformationenBridge.php
index c7c935fd336..349a9d8a84e 100644
--- a/bridges/SchweinfurtBuergerinformationenBridge.php
+++ b/bridges/SchweinfurtBuergerinformationenBridge.php
@@ -43,10 +43,6 @@ public function collectData()
 
         foreach ($articleIDs as $articleID) {
             $this->items[] = $this->generateItemFromArticle($articleID);
-
-            if (Debug::isEnabled()) {
-                break;
-            }
         }
     }
 
diff --git a/config.default.ini.php b/config.default.ini.php
index f67f315ff61..3a347036d60 100644
--- a/config.default.ini.php
+++ b/config.default.ini.php
@@ -15,6 +15,13 @@
 ; Display a system message to users.
 message = ""
 
+; Whether to enable debug mode.
+enable_debug_mode = false
+
+; Enable debug mode only for these permitted ip addresses
+; debug_mode_whitelist[] = 127.0.0.1
+; debug_mode_whitelist[] = 192.168.1.10
+
 [http]
 timeout = 60
 useragent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0"
diff --git a/docs/04_For_Developers/05_Debug_mode.md b/docs/04_For_Developers/05_Debug_mode.md
index 482ff0f5c46..6bdb1d484a0 100644
--- a/docs/04_For_Developers/05_Debug_mode.md
+++ b/docs/04_For_Developers/05_Debug_mode.md
@@ -5,23 +5,29 @@ Enabling debug mode on a public server may result in malicious clients retrievin
 ***
 
 Debug mode enables error reporting and prevents loading data from the cache (data is still written to the cache).
-To enable debug mode, create a file named 'DEBUG' in the root directory of RSS-Bridge (next to `index.php`). For further security, insert your IP address in the file. You can add multiple addresses, one per line.
+To enable debug mode, set in `config.ini.php`:
+
+    enable_debug_mode = true
+
+Allow only explicit ip addresses:
+
+    debug_mode_whitelist[] = 127.0.0.1
+    debug_mode_whitelist[] = 192.168.1.10
 
 _Notice_:
 
 * An empty file enables debug mode for anyone!
 * The bridge whitelist still applies! (debug mode does **not** enable all bridges)
 
-RSS-Bridge will give you a visual feedback when debug mode is enabled:
-
-![twitter bridge](../images/debug_mode.png)
+RSS-Bridge will give you a visual feedback when debug mode is enabled.
 
 While debug mode is active, RSS-Bridge will write additional data to your servers `error.log`.
 
 Debug mode is controlled by the static class `Debug`. It provides three core functions:
 
-`Debug::isEnabled()`: Returns `true` if debug mode is enabled.
-`Debug::isSecure()`: Returns `true` if your client is on the debug whitelist.
-`Debug::log($message)`: Adds a message to `error.log`. It takes one parameter, which can be anything. For example: `Debug::log('Hello World!');`
+* `Debug::isEnabled()`: Returns `true` if debug mode is enabled.
+* `Debug::log($message)`: Adds a message to `error.log`. It takes one parameter, which can be anything.
+
+Example: `Debug::log('Hello World!');`
 
 **Notice**: `Debug::log($message)` calls `Debug::isEnabled()` internally. You don't have to do that manually.
\ No newline at end of file
diff --git a/docs/images/debug_mode.png b/docs/images/debug_mode.png
deleted file mode 100644
index 6ab8917bb62..00000000000
Binary files a/docs/images/debug_mode.png and /dev/null differ
diff --git a/lib/Configuration.php b/lib/Configuration.php
index bdbd830bcc9..6eec33f6f0e 100644
--- a/lib/Configuration.php
+++ b/lib/Configuration.php
@@ -114,6 +114,15 @@ public static function loadConfiguration(array $customConfig = [], array $env =
             }
         }
 
+        if (file_exists(__DIR__ . '/../DEBUG')) {
+            // The debug mode has been moved to config. Preserve existing installs which has this DEBUG file.
+            self::setConfig('system', 'enable_debug_mode', true);
+            $debug = trim(file_get_contents(__DIR__ . '/../DEBUG'));
+            if ($debug) {
+                self::setConfig('system', 'debug_mode_whitelist', explode("\n", str_replace("\r", '', $debug)));
+            }
+        }
+
         if (
             !is_string(self::getConfig('system', 'timezone'))
             || !in_array(self::getConfig('system', 'timezone'), timezone_identifiers_list(DateTimeZone::ALL_WITH_BC))
@@ -121,6 +130,13 @@ public static function loadConfiguration(array $customConfig = [], array $env =
             self::throwConfigError('system', 'timezone');
         }
 
+        if (!is_bool(self::getConfig('system', 'enable_debug_mode'))) {
+            self::throwConfigError('system', 'enable_debug_mode', 'Is not a valid Boolean');
+        }
+        if (!is_array(self::getConfig('system', 'debug_mode_whitelist') ?: [])) {
+            self::throwConfigError('system', 'debug_mode_whitelist', 'Is not a valid array');
+        }
+
         if (!is_string(self::getConfig('proxy', 'url'))) {
             self::throwConfigError('proxy', 'url', 'Is not a valid string');
         }
diff --git a/lib/Debug.php b/lib/Debug.php
index 9210ebc801c..f6a8d1052b4 100644
--- a/lib/Debug.php
+++ b/lib/Debug.php
@@ -1,106 +1,23 @@
 <?php
 
-/**
- * This file is part of RSS-Bridge, a PHP project capable of generating RSS and
- * Atom feeds for websites that don't have one.
- *
- * For the full license information, please view the UNLICENSE file distributed
- * with this source code.
- *
- * @package Core
- * @license http://unlicense.org/ UNLICENSE
- * @link    https://github.com/rss-bridge/rss-bridge
- */
-
-/**
- * Implements functions for debugging purposes. Debugging can be enabled by
- * placing a file named DEBUG in {@see PATH_ROOT}.
- *
- * The file specifies a whitelist of IP addresses on which debug mode will be
- * enabled. An empty file enables debug mode for everyone (highly discouraged
- * for public servers!). Each line in the file specifies one client in the
- * whitelist. For example:
- *
- * * `192.168.1.72`
- * * `127.0.0.1`
- * * `::1`
- *
- * Notice: If you are running RSS-Bridge on your local machine, you need to add
- * localhost (either `127.0.0.1` for IPv4 or `::1` for IPv6) to your whitelist!
- *
- * Warning: In debug mode your server may display sensitive information! For
- * security reasons it is recommended to whitelist only specific IP addresses.
- */
 class Debug
 {
     /**
-     * Indicates if debug mode is enabled.
-     *
-     * Do not access this property directly!
-     * Use {@see Debug::isEnabled()} instead.
-     *
-     * @var bool
+     * Convenience function for Configuration::getConfig('system', 'enable_debug_mode')
      */
-    private static $enabled = false;
-
-    /**
-     * Indicates if debug mode is secure.
-     *
-     * Do not access this property directly!
-     * Use {@see Debug::isSecure()} instead.
-     *
-     * @var bool
-     */
-    private static $secure = false;
-
-    /**
-     * Returns true if debug mode is enabled
-     *
-     * If debug mode is enabled, sets `display_errors = 1` and `error_reporting = E_ALL`
-     *
-     * @return bool True if enabled.
-     */
-    public static function isEnabled()
+    public static function isEnabled(): bool
     {
-        static $firstCall = true; // Initialized on first call
-
-        if ($firstCall && file_exists(__DIR__ . '/../DEBUG')) {
-            $debug_whitelist = trim(file_get_contents(__DIR__ . '/../DEBUG'));
-
-            self::$enabled = empty($debug_whitelist) || in_array(
-                $_SERVER['REMOTE_ADDR'],
-                explode("\n", str_replace("\r", '', $debug_whitelist))
-            );
-
-            if (self::$enabled) {
-                self::$secure = !empty($debug_whitelist);
-            }
-
-            $firstCall = false; // Skip check on next call
+        $ip = $_SERVER['REMOTE_ADDR'];
+        $enableDebugMode = Configuration::getConfig('system', 'enable_debug_mode');
+        $debugModeWhitelist = Configuration::getConfig('system', 'debug_mode_whitelist') ?: [];
+        if ($enableDebugMode && ($debugModeWhitelist === [] || in_array($ip, $debugModeWhitelist))) {
+            return true;
         }
-
-        return self::$enabled;
-    }
-
-    /**
-     * Returns true if debug mode is enabled only for specific IP addresses.
-     *
-     * Notice: The security flag is set by {@see Debug::isEnabled()}. If this
-     * function is called before {@see Debug::isEnabled()}, the default value is
-     * false!
-     *
-     * @return bool True if debug mode is secure
-     */
-    public static function isSecure()
-    {
-        return self::$secure;
+        return false;
     }
 
     public static function log($message)
     {
-        if (!self::isEnabled()) {
-            return;
-        }
         $e = new \Exception();
         $trace = trace_from_exception($e);
         // Drop the current frame
diff --git a/lib/FeedExpander.php b/lib/FeedExpander.php
index edfe99d44bd..1bac617999a 100644
--- a/lib/FeedExpander.php
+++ b/lib/FeedExpander.php
@@ -113,9 +113,7 @@ public function collectExpandableDatas($url, $maxItems = -1)
         if ($rssContent === false) {
             $xmlErrors = libxml_get_errors();
             foreach ($xmlErrors as $xmlError) {
-                if (Debug::isEnabled()) {
-                    Debug::log(trim($xmlError->message));
-                }
+                Logger::debug(trim($xmlError->message));
             }
             if ($xmlErrors) {
                 // Render only the first error into exception message
diff --git a/lib/Logger.php b/lib/Logger.php
index 9bbdd512e94..e15035fe503 100644
--- a/lib/Logger.php
+++ b/lib/Logger.php
@@ -6,9 +6,7 @@ final class Logger
 {
     public static function debug(string $message, array $context = [])
     {
-        if (Debug::isEnabled()) {
-            self::log('DEBUG', $message, $context);
-        }
+        self::log('DEBUG', $message, $context);
     }
 
     public static function info(string $message, array $context = []): void
@@ -28,6 +26,11 @@ public static function error(string $message, array $context = []): void
 
     private static function log(string $level, string $message, array $context = []): void
     {
+        if (!Debug::isEnabled() && $level === 'DEBUG') {
+            // Don't log this debug log record because debug mode is disabled
+            return;
+        }
+
         if (isset($context['e'])) {
             /** @var \Throwable $e */
             $e = $context['e'];
@@ -66,7 +69,13 @@ private static function log(string $level, string $message, array $context = [])
             $message,
             $context ? Json::encode($context) : ''
         );
+
         // Log to stderr/stdout whatever that is
+        // todo: extract to log handler
         error_log($text);
+
+        // Log to file
+        // todo: extract to log handler
+        //file_put_contents('/tmp/rss-bridge.log', $text, FILE_APPEND);
     }
 }
diff --git a/lib/RssBridge.php b/lib/RssBridge.php
index 62e8acc58cb..e6f1c9e4409 100644
--- a/lib/RssBridge.php
+++ b/lib/RssBridge.php
@@ -42,6 +42,7 @@ private function run($request): void
             );
             Logger::warning($text);
             if (Debug::isEnabled()) {
+                // todo: extract to log handler
                 print sprintf("<pre>%s</pre>\n", e($text));
             }
         });
@@ -59,6 +60,7 @@ private function run($request): void
                 );
                 Logger::error($message);
                 if (Debug::isEnabled()) {
+                    // todo: extract to log handler
                     print sprintf("<pre>%s</pre>\n", e($message));
                 }
             }
diff --git a/lib/bootstrap.php b/lib/bootstrap.php
index 8e5cf69cc9a..98c7b54d955 100644
--- a/lib/bootstrap.php
+++ b/lib/bootstrap.php
@@ -40,6 +40,7 @@
 const REPOSITORY = 'https://github.com/RSS-Bridge/rss-bridge/';
 
 // Allow larger files for simple_html_dom
+// todo: extract to config (if possible)
 const MAX_FILE_SIZE = 10000000;
 
 // Files
diff --git a/lib/contents.php b/lib/contents.php
index ebd4ee2cc63..a1630e3ca19 100644
--- a/lib/contents.php
+++ b/lib/contents.php
@@ -438,14 +438,17 @@ function getSimpleHTMLDOMCached(
         $time !== false
         && (time() - $duration < $time)
         && !Debug::isEnabled()
-    ) { // Contents within duration
+    ) {
+        // Contents within duration and debug mode is disabled
         $content = $cache->loadData();
-    } else { // Content not within duration
+    } else {
+        // Contents not within duration, or debug mode is enabled
         $content = getContents(
             $url,
             $header ?? [],
             $opts ?? []
         );
+        // todo: fix bad if statement
         if ($content !== false) {
             $cache->saveData($content);
         }
diff --git a/lib/html.php b/lib/html.php
index 7f4f12017c5..ca0a411c872 100644
--- a/lib/html.php
+++ b/lib/html.php
@@ -1,23 +1,34 @@
 <?php
 
 /**
- * This file is part of RSS-Bridge, a PHP project capable of generating RSS and
- * Atom feeds for websites that don't have one.
- *
- * For the full license information, please view the UNLICENSE file distributed
- * with this source code.
- *
- * @package Core
- * @license http://unlicense.org/ UNLICENSE
- * @link    https://github.com/rss-bridge/rss-bridge
+ * Render template using base.html.php as base
  */
-
 function render(string $template, array $context = []): string
 {
     if ($template === 'base.html.php') {
         throw new \Exception('Do not render base.html.php into itself');
     }
-    $context['system_message'] = Configuration::getConfig('system', 'message');
+    $context['messages'] = $context['messages'] ?? [];
+    if (Configuration::getConfig('system', 'message')) {
+        $context['messages'][] = [
+            'body' => Configuration::getConfig('system', 'message'),
+            'level' => 'info',
+        ];
+    }
+    if (Debug::isEnabled()) {
+        $debugModeWhitelist = Configuration::getConfig('system', 'debug_mode_whitelist') ?: [];
+        if ($debugModeWhitelist === []) {
+            $context['messages'][] = [
+                'body' => 'Warning : Debug mode is active from any location, make sure only you can access RSS-Bridge.',
+                'level' => 'error'
+            ];
+        } else {
+            $context['messages'][] = [
+                'body' => 'Warning : Debug mode is active from your IP address, your requests will bypass the cache.',
+                'level' => 'warning'
+            ];
+        }
+    }
     $context['page'] = render_template($template, $context);
     return render_template('base.html.php', $context);
 }
diff --git a/static/style.css b/static/style.css
index 570ee014812..a83e25e4214 100644
--- a/static/style.css
+++ b/static/style.css
@@ -71,15 +71,34 @@ header {
     text-align: center;
 }
 
-section.warning {
+.alert-info {
+    margin-bottom: 15px;
+    color: white;
+    font-weight: bold;
+    background-color: rgb(33, 150, 243);
+    padding: 15px;
+    border-radius: 4px;
+    text-align: center;
+}
+
+.alert-warning {
     background-color: #ffc600;
     color: #5f5f5f;
+    margin-bottom: 15px;
+    font-weight: bold;
+    padding: 15px;
+    border-radius: 4px;
+    text-align: center;
 }
 
-section.critical-warning {
+.alert-error {
     background-color: #cf3e3e;
     font-weight: bold;
     color: white;
+    margin-bottom: 15px;
+    padding: 15px;
+    border-radius: 4px;
+    text-align: center;
 }
 
 select,
@@ -342,15 +361,6 @@ button {
     width: 200px;
 }
 
-.alert {
-    margin-bottom: 15px;
-    color: white;
-    font-weight: bold;
-    background-color: rgb(33, 150, 243);
-    padding: 15px;
-    border-radius: 4px;
-}
-
 @media screen and (max-width: 767px) {
     .container {
         width: 100%;
diff --git a/templates/base.html.php b/templates/base.html.php
index 00728785c83..ca31823dc35 100644
--- a/templates/base.html.php
+++ b/templates/base.html.php
@@ -17,11 +17,11 @@
             </a>
         </header>
 
-        <?php if ($system_message): ?>
-            <div class="alert">
-                <?= raw($system_message) ?>
+        <?php foreach ($messages as $message): ?>
+            <div class="alert-<?= raw($message['level'] ?? 'info') ?>">
+                <?= raw($message['body']) ?>
             </div>
-        <?php endif; ?>
+        <?php endforeach; ?>
 
         <?= raw($page) ?>
     </div>
diff --git a/templates/frontpage.html.php b/templates/frontpage.html.php
index 5daa63bdd66..63f4a2ab2fa 100644
--- a/templates/frontpage.html.php
+++ b/templates/frontpage.html.php
@@ -4,20 +4,6 @@
     document.addEventListener('DOMContentLoaded', rssbridge_list_search);
 </script>
 
-<?php if (Debug::isEnabled()): ?>
-    <?php if (!Debug::isSecure()): ?>
-        <section class="critical-warning">
-            Warning : Debug mode is active from any location,
-            make sure only you can access RSS-Bridge.
-        </section>
-    <?php else: ?>
-        <section class="warning">
-            Warning : Debug mode is active from your IP address,
-            your requests will bypass the cache.
-        </section>
-    <?php endif; ?>
-<?php endif; ?>
-
 <section class="searchbar">
     <h3>Search</h3>
     <input