diff --git a/js/feedEngine/sources.js b/js/feedEngine/sources.js
index 6cf89cb9..8c3aa03d 100644
--- a/js/feedEngine/sources.js
+++ b/js/feedEngine/sources.js
@@ -16,7 +16,7 @@ function normalizeAuthor(value) {
     return "";
   }
   const trimmed = value.trim();
-  return trimmed;
+  return trimmed ? trimmed.toLowerCase() : "";
 }
 
 function normalizeActorCandidate(...values) {
diff --git a/js/subscriptions.js b/js/subscriptions.js
index 46ae9e16..6a3e1d64 100644
--- a/js/subscriptions.js
+++ b/js/subscriptions.js
@@ -20,6 +20,14 @@ import { devLogger, userLogger } from "./utils/logger.js";
 import moderationService from "./services/moderationService.js";
 import nostrService from "./services/nostrService.js";
 
+function normalizeHexPubkey(value) {
+  if (typeof value !== "string") {
+    return "";
+  }
+  const trimmed = value.trim();
+  return trimmed ? trimmed.toLowerCase() : "";
+}
+
 const getApp = () => getApplication();
 
 /**
@@ -122,7 +130,10 @@ class SubscriptionsManager {
       const subArray = Array.isArray(parsed.subPubkeys)
         ? parsed.subPubkeys
         : [];
-      this.subscribedPubkeys = new Set(subArray);
+      const normalized = subArray
+        .map((value) => normalizeHexPubkey(value))
+        .filter((value) => Boolean(value));
+      this.subscribedPubkeys = new Set(normalized);
 
       this.loaded = true;
     } catch (err) {
@@ -131,7 +142,11 @@ class SubscriptionsManager {
   }
 
   isSubscribed(channelHex) {
-    return this.subscribedPubkeys.has(channelHex);
+    const normalized = normalizeHexPubkey(channelHex);
+    if (!normalized) {
+      return false;
+    }
+    return this.subscribedPubkeys.has(normalized);
   }
 
   getSubscribedAuthors() {
@@ -139,14 +154,19 @@ class SubscriptionsManager {
   }
 
   async addChannel(channelHex, userPubkey) {
+    const normalizedChannel = normalizeHexPubkey(channelHex);
     if (!userPubkey) {
       throw new Error("No user pubkey => cannot addChannel.");
     }
-    if (this.subscribedPubkeys.has(channelHex)) {
+    if (!normalizedChannel) {
+      devLogger.warn("Attempted to subscribe to invalid pubkey", channelHex);
+      return;
+    }
+    if (this.subscribedPubkeys.has(normalizedChannel)) {
       devLogger.log("Already subscribed to", channelHex);
       return;
     }
-    this.subscribedPubkeys.add(channelHex);
+    this.subscribedPubkeys.add(normalizedChannel);
     await this.publishSubscriptionList(userPubkey);
     this.refreshActiveFeed({ reason: "subscription-update" }).catch((error) => {
       userLogger.warn(
@@ -157,14 +177,19 @@ class SubscriptionsManager {
   }
 
   async removeChannel(channelHex, userPubkey) {
+    const normalizedChannel = normalizeHexPubkey(channelHex);
     if (!userPubkey) {
       throw new Error("No user pubkey => cannot removeChannel.");
     }
-    if (!this.subscribedPubkeys.has(channelHex)) {
+    if (!normalizedChannel) {
+      devLogger.warn("Attempted to remove invalid pubkey from subscriptions", channelHex);
+      return;
+    }
+    if (!this.subscribedPubkeys.has(normalizedChannel)) {
       devLogger.log("Channel not found in subscription list:", channelHex);
       return;
     }
-    this.subscribedPubkeys.delete(channelHex);
+    this.subscribedPubkeys.delete(normalizedChannel);
     await this.publishSubscriptionList(userPubkey);
     this.refreshActiveFeed({ reason: "subscription-update" }).catch((error) => {
       userLogger.warn(
@@ -515,7 +540,9 @@ class SubscriptionsManager {
 
   buildFeedRuntime({ app, authors = [], limit = null } = {}) {
     const normalizedAuthors = Array.isArray(authors)
-      ? authors.filter((author) => typeof author === "string" && author)
+      ? authors
+          .map((author) => normalizeHexPubkey(author))
+          .filter((author) => Boolean(author))
       : [];
 
     const blacklist =
diff --git a/tests/subscriptions-feed.test.mjs b/tests/subscriptions-feed.test.mjs
index aa669294..086a4243 100644
--- a/tests/subscriptions-feed.test.mjs
+++ b/tests/subscriptions-feed.test.mjs
@@ -255,9 +255,61 @@ async function testLimitApplied() {
   );
 }
 
+async function testAuthorNormalization() {
+  const engine = createFeedEngine();
+  const feedName = "subscriptions-author-normalization";
+
+  const videos = [
+    { id: "video-mixed", pubkey: "pubkey-lower", created_at: 123 },
+  ];
+
+  const calls = [];
+  const service = {
+    async getActiveVideosByAuthors(authors, options) {
+      calls.push({ authors, options });
+      return videos;
+    },
+    async getFilteredActiveVideos() {
+      throw new Error("case normalization run should not fall back to filtered lookup");
+    },
+  };
+
+  engine.registerFeed(feedName, {
+    source: createSubscriptionAuthorsSource({ service }),
+    stages: [
+      createBlacklistFilterStage({ shouldIncludeVideo: () => true }),
+      createDedupeByRootStage(),
+    ],
+    sorter: createChronologicalSorter(),
+  });
+
+  const result = await engine.runFeed(feedName, {
+    runtime: {
+      subscriptionAuthors: [" PUBKEY-LOWER "],
+      authors: ["PUBKEY-LOWER"],
+      blacklistedEventIds: new Set(),
+      isAuthorBlocked: () => false,
+    },
+  });
+
+  assert.equal(calls.length, 1, "case normalization run should call targeted lookup once");
+  assert.deepEqual(
+    calls[0].authors,
+    ["pubkey-lower"],
+    "authors passed to the service should be lowercased",
+  );
+
+  assert.deepEqual(
+    result.videos.map((video) => video.id),
+    ["video-mixed"],
+    "videos should be retained when the service pubkey casing differs",
+  );
+}
+
 await testBlockedCreatorsFiltered();
 await testDuplicateRootsFiltered();
 await testNoAuthorsSkipsLookup();
 await testLimitApplied();
+await testAuthorNormalization();
 
 console.log("subscriptions-feed tests passed");