diff --git a/index.js b/index.js
index 5b50e5b..38d3cbc 100644
--- a/index.js
+++ b/index.js
@@ -95,6 +95,7 @@ export default class YouTubeEndpoint {
     protectedRouter.get("/likes/connect", likesController.connect);
     protectedRouter.post("/likes/disconnect", likesController.disconnect);
     protectedRouter.post("/likes/sync", likesController.sync);
+    protectedRouter.post("/likes/reset", likesController.reset);
 
     return protectedRouter;
   }
diff --git a/lib/controllers/likes.js b/lib/controllers/likes.js
index 475e590..f7048be 100644
--- a/lib/controllers/likes.js
+++ b/lib/controllers/likes.js
@@ -65,7 +65,7 @@ export const likesController = {
       }
 
       // Flash messages from query params
-      const { error: qError, connected, disconnected, synced, skipped } = request.query;
+      const { error: qError, connected, disconnected, synced, skipped, reset } = request.query;
       let success = null;
       let notice = null;
       if (connected) success = response.locals.__("youtube.likes.flash.connected");
@@ -75,6 +75,9 @@ export const likesController = {
         const sk = parseInt(skipped, 10) || 0;
         success = response.locals.__("youtube.likes.flash.synced", { synced: s, skipped: sk });
       }
+      if (reset !== undefined) {
+        notice = response.locals.__("youtube.likes.flash.reset", { count: parseInt(reset, 10) || 0 });
+      }
 
       response.render("youtube-likes", {
         title: response.locals.__("youtube.likes.title"),
@@ -221,6 +224,49 @@ export const likesController = {
     }
   },
 
+  /**
+   * POST /likes/reset — delete all like posts, seen set, and baseline
+   */
+  async reset(request, response) {
+    try {
+      const db = request.app.locals.application.getYoutubeDb?.();
+      if (!db) {
+        return response.status(503).json({ error: "Database not available" });
+      }
+
+      const postsCollection = request.app.locals.application.collections?.get("posts");
+
+      let deletedPosts = 0;
+      if (postsCollection) {
+        const result = await postsCollection.deleteMany({
+          "properties.post-type": "like",
+          "properties.youtube-video-id": { $exists: true },
+        });
+        deletedPosts = result.deletedCount || 0;
+      }
+
+      const seenResult = await db.collection("youtubeLikesSeen").deleteMany({});
+      const deletedSeen = seenResult.deletedCount || 0;
+
+      await db.collection("youtubeMeta").deleteOne({ key: "likes_baseline" });
+      await db.collection("youtubeMeta").deleteOne({ key: "likes_sync" });
+
+      console.log(`[YouTube] Reset: deleted ${deletedPosts} posts, ${deletedSeen} seen entries, cleared baseline`);
+
+      if (request.accepts("json")) {
+        return response.json({ deletedPosts, deletedSeen });
+      }
+
+      response.redirect(`${request.baseUrl}/likes?reset=${deletedPosts}`);
+    } catch (error) {
+      console.error("[YouTube] Reset error:", error);
+      if (request.accepts("json")) {
+        return response.status(500).json({ error: error.message });
+      }
+      response.redirect(`${request.baseUrl}/likes?error=${encodeURIComponent(error.message)}`);
+    }
+  },
+
   /**
    * GET /api/likes — public JSON API for synced likes
    */
diff --git a/locales/de.json b/locales/de.json
index aa97160..bd7f286 100644
--- a/locales/de.json
+++ b/locales/de.json
@@ -45,10 +45,14 @@
       "seenVideos": "Videos gesehen",
       "likePosts": "Like-Beiträge erstellt",
       "viewOnYouTube": "Auf YouTube ansehen",
+      "reset": "Zurücksetzen",
+      "resetDescription": "Alle synchronisierten Like-Beiträge, gesehene Video-IDs und Baseline löschen. Nächste Synchronisierung erstellt eine neue Baseline.",
+      "resetConfirm": "Alle Likes-Daten löschen",
       "flash": {
         "connected": "YouTube-Konto erfolgreich verbunden. Starte eine Synchronisierung, um bestehende Likes zu erfassen.",
         "disconnected": "YouTube-Konto getrennt.",
-        "synced": "Synchronisierung abgeschlossen: %{synced} neu, %{skipped} übersprungen."
+        "synced": "Synchronisierung abgeschlossen: %{synced} neu, %{skipped} übersprungen.",
+        "reset": "Zurücksetzen abgeschlossen: %{count} Like-Beiträge gelöscht. Baseline gelöscht."
       },
       "error": {
         "noOAuth": "YouTube OAuth ist nicht konfiguriert. Setze YOUTUBE_OAUTH_CLIENT_ID und YOUTUBE_OAUTH_CLIENT_SECRET."
diff --git a/locales/en.json b/locales/en.json
index 0634ffa..4ee8e89 100644
--- a/locales/en.json
+++ b/locales/en.json
@@ -45,10 +45,14 @@
       "seenVideos": "videos seen",
       "likePosts": "like posts created",
       "viewOnYouTube": "View on YouTube",
+      "reset": "Reset",
+      "resetDescription": "Delete all synced like posts, seen video IDs, and baseline. Next sync will re-baseline.",
+      "resetConfirm": "Delete all likes data",
       "flash": {
         "connected": "YouTube account connected successfully. Run a sync to baseline your existing likes.",
         "disconnected": "YouTube account disconnected.",
-        "synced": "Sync complete: %{synced} new, %{skipped} skipped."
+        "synced": "Sync complete: %{synced} new, %{skipped} skipped.",
+        "reset": "Reset complete: %{count} like posts deleted. Baseline cleared."
       },
       "error": {
         "noOAuth": "YouTube OAuth is not configured. Set YOUTUBE_OAUTH_CLIENT_ID and YOUTUBE_OAUTH_CLIENT_SECRET."
diff --git a/views/youtube-likes.njk b/views/youtube-likes.njk
index 0d02164..a88246d 100644
--- a/views/youtube-likes.njk
+++ b/views/youtube-likes.njk
@@ -73,6 +73,15 @@
         </form>
       {% endcall %}
 
+      {# ── Reset (destructive, hidden in details) ── #}
+      {% call section({ title: __("youtube.likes.reset") }) %}
+        {% call details({ summary: __("youtube.likes.resetDescription") }) %}
+          <form method="post" action="{{ mountPath }}/likes/reset">
+            {{ button({ type: "submit", text: __("youtube.likes.resetConfirm") }) }}
+          </form>
+        {% endcall %}
+      {% endcall %}
+
       {# ── Recent likes ── #}
       {% call section({ title: __("youtube.likes.recentLikes") }) %}
         {% if recentLikes and recentLikes.length > 0 %}