diff --git a/src/components/article/ArticleCard.tsx b/src/components/article/ArticleCard.tsx
index 9cdeaab..8a88a13 100644
--- a/src/components/article/ArticleCard.tsx
+++ b/src/components/article/ArticleCard.tsx
@@ -71,7 +71,7 @@ export function ArticleCard({ event }: { event: NDKEvent }) {
               {profile?.picture ? (
                 <img
                   src={profile.picture}
-                  alt=""
+                  alt={`${authorName}'s avatar`}
                   className="w-5 h-5 rounded-sm object-cover"
                   onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
                 />
@@ -108,7 +108,7 @@ export function ArticleCard({ event }: { event: NDKEvent }) {
           <div className="shrink-0 w-24 h-20 rounded-sm overflow-hidden bg-bg-raised">
             <img
               src={image}
-              alt=""
+              alt={`Cover image for ${title || "article"}`}
               className="w-full h-full object-cover"
               onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
             />
diff --git a/src/components/article/ArticleView.tsx b/src/components/article/ArticleView.tsx
index a0512be..d8326b6 100644
--- a/src/components/article/ArticleView.tsx
+++ b/src/components/article/ArticleView.tsx
@@ -43,7 +43,7 @@ function AuthorRow({ pubkey, publishedAt, readingTime }: { pubkey: string; publi
     <div className="flex items-center gap-3 mb-6">
       <button className="shrink-0" onClick={() => openProfile(pubkey)}>
         {profile?.picture ? (
-          <img src={profile.picture} alt="" className="w-9 h-9 rounded-sm object-cover hover:opacity-80 transition-opacity"
+          <img src={profile.picture} alt={`${name}'s avatar`} className="w-9 h-9 rounded-sm object-cover hover:opacity-80 transition-opacity"
             onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }} />
         ) : (
           <div className="w-9 h-9 rounded-sm bg-bg-raised border border-border flex items-center justify-center text-text-dim text-sm">
@@ -361,7 +361,7 @@ export function ArticleView() {
                 <div className="mb-6 -mx-2">
                   <img
                     src={image}
-                    alt=""
+                    alt={`Cover image for ${title || "article"}`}
                     className="w-full aspect-video object-cover rounded-sm"
                     onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
                   />
diff --git a/src/components/dm/DMView.tsx b/src/components/dm/DMView.tsx
index 3ade4ee..e12c14f 100644
--- a/src/components/dm/DMView.tsx
+++ b/src/components/dm/DMView.tsx
@@ -56,7 +56,7 @@ function ConvRow({
       }`}
     >
       {profile?.picture ? (
-        <img src={profile.picture} alt="" className="w-8 h-8 rounded-sm object-cover shrink-0"
+        <img src={profile.picture} alt={`${name}'s avatar`} className="w-8 h-8 rounded-sm object-cover shrink-0"
           onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }} />
       ) : (
         <div className="w-8 h-8 rounded-sm bg-bg-raised border border-border flex items-center justify-center text-text-dim text-xs shrink-0">
@@ -177,7 +177,7 @@ function ThreadPanel({
       {/* Header */}
       <div className="border-b border-border px-4 py-2.5 flex items-center gap-3 shrink-0">
         {profile?.picture && (
-          <img src={profile.picture} alt="" className="w-7 h-7 rounded-sm object-cover" />
+          <img src={profile.picture} alt={`${name}'s avatar`} className="w-7 h-7 rounded-sm object-cover" />
         )}
         <button
           onClick={() => openProfile(partnerPubkey)}
diff --git a/src/components/feed/ComposeBox.tsx b/src/components/feed/ComposeBox.tsx
index 6529dda..28c8fc2 100644
--- a/src/components/feed/ComposeBox.tsx
+++ b/src/components/feed/ComposeBox.tsx
@@ -213,7 +213,7 @@ export function ComposeBox({ onPublished, onNoteInjected }: { onPublished?: () =
           {avatar ? (
             <img
               src={avatar}
-              alt=""
+              alt="Your avatar"
               className="w-9 h-9 rounded-sm object-cover bg-bg-raised"
               onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
             />
@@ -252,7 +252,7 @@ export function ComposeBox({ onPublished, onNoteInjected }: { onPublished?: () =
                   ) : (
                     <img
                       src={url}
-                      alt=""
+                      alt="Attachment preview"
                       className="h-16 w-auto rounded-sm border border-border object-cover"
                       onError={(e) => { (e.target as HTMLImageElement).className = "h-16 w-20 rounded-sm border border-border bg-bg-raised"; }}
                     />
diff --git a/src/components/feed/FountainCard.tsx b/src/components/feed/FountainCard.tsx
index e3ff763..f422680 100644
--- a/src/components/feed/FountainCard.tsx
+++ b/src/components/feed/FountainCard.tsx
@@ -68,7 +68,7 @@ export function FountainCard({ seg }: { seg: ContentSegment }) {
       {episode.artworkUrl ? (
         <img
           src={episode.artworkUrl}
-          alt=""
+          alt={`${episode.title || "Episode"} artwork`}
           className="w-12 h-12 rounded-sm object-cover shrink-0"
           loading="lazy"
           onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
diff --git a/src/components/feed/InlineReplyBox.tsx b/src/components/feed/InlineReplyBox.tsx
index 4b9ddb0..26e58ff 100644
--- a/src/components/feed/InlineReplyBox.tsx
+++ b/src/components/feed/InlineReplyBox.tsx
@@ -175,7 +175,7 @@ export function InlineReplyBox({ event, name, rootEvent }: InlineReplyBoxProps)
               ) : (
                 <img
                   src={url}
-                  alt=""
+                  alt="Attachment preview"
                   className="h-12 w-auto rounded-sm border border-border object-cover"
                   onError={(e) => { (e.target as HTMLImageElement).className = "h-12 w-16 rounded-sm border border-border bg-bg-raised"; }}
                 />
diff --git a/src/components/feed/MediaCards.tsx b/src/components/feed/MediaCards.tsx
index 7d35904..abdaf1a 100644
--- a/src/components/feed/MediaCards.tsx
+++ b/src/components/feed/MediaCards.tsx
@@ -83,7 +83,7 @@ export function YouTubeCard({ seg }: { seg: ContentSegment }) {
     >
       <img
         src={`https://img.youtube.com/vi/${seg.mediaId}/hqdefault.jpg`}
-        alt=""
+        alt="Video thumbnail"
         className="w-28 h-16 rounded-sm object-cover shrink-0"
         loading="lazy"
       />
diff --git a/src/components/feed/NoteActions.tsx b/src/components/feed/NoteActions.tsx
index fb967cc..6f22843 100644
--- a/src/components/feed/NoteActions.tsx
+++ b/src/components/feed/NoteActions.tsx
@@ -120,7 +120,7 @@ export function NoteActions({ event, onReplyToggle, showReply }: NoteActionsProp
           {/* Emoji picker popover */}
           {showEmojiPicker && (
             <>
-              <div className="fixed inset-0 z-[9]" onClick={() => setShowEmojiPicker(false)} />
+              <div className="fixed inset-0 z-[9]" role="presentation" onClick={() => setShowEmojiPicker(false)} />
               <div className="absolute bottom-6 left-0 bg-bg-raised border border-border shadow-lg z-10 flex gap-0.5 px-1.5 py-1">
                 {REACTION_EMOJIS.map((emoji) => (
                   <button
diff --git a/src/components/feed/NoteCard.tsx b/src/components/feed/NoteCard.tsx
index e637671..3aa07da 100644
--- a/src/components/feed/NoteCard.tsx
+++ b/src/components/feed/NoteCard.tsx
@@ -67,11 +67,11 @@ export function NoteCard({ event, focused, onReplyInThread }: NoteCardProps) {
     >
       <div className="flex gap-3">
         {/* Avatar */}
-        <div className="shrink-0 cursor-pointer" onClick={() => openProfile(event.pubkey)}>
+        <button className="shrink-0 cursor-pointer" aria-label={`View profile of ${name}`} onClick={() => openProfile(event.pubkey)}>
           {avatar ? (
             <img
               src={avatar}
-              alt=""
+              alt={`${name}'s avatar`}
               className="w-9 h-9 rounded-sm object-cover bg-bg-raised hover:opacity-80 transition-opacity"
               loading="lazy"
               onError={(e) => {
@@ -83,7 +83,7 @@ export function NoteCard({ event, focused, onReplyInThread }: NoteCardProps) {
               {name.charAt(0).toUpperCase()}
             </div>
           )}
-        </div>
+        </button>
 
         {/* Content */}
         <div className="min-w-0 flex-1">
@@ -103,14 +103,16 @@ export function NoteCard({ event, focused, onReplyInThread }: NoteCardProps) {
               <div className="relative ml-auto">
                 <button
                   onClick={() => setMenuOpen((v) => !v)}
+                  aria-label="More actions"
+                  aria-expanded={menuOpen}
                   className="text-text-dim hover:text-text text-[14px] px-1 leading-none opacity-0 group-hover/card:opacity-100 transition-opacity"
                 >
                   ⋯
                 </button>
                 {menuOpen && (
                   <>
-                    <div className="fixed inset-0 z-[9]" onClick={() => setMenuOpen(false)} />
-                    <div className="absolute right-0 top-5 bg-bg-raised border border-border shadow-lg z-10 w-32">
+                    <div className="fixed inset-0 z-[9]" role="presentation" onClick={() => setMenuOpen(false)} />
+                    <div role="menu" className="absolute right-0 top-5 bg-bg-raised border border-border shadow-lg z-10 w-32">
                       <button
                         onClick={() => { setMenuOpen(false); follows.includes(event.pubkey) ? unfollow(event.pubkey) : follow(event.pubkey); }}
                         className="w-full text-left px-3 py-2 text-[11px] text-text-muted hover:text-accent hover:bg-bg-hover transition-colors"
diff --git a/src/components/feed/NoteContent.tsx b/src/components/feed/NoteContent.tsx
index 19b5d72..137f217 100644
--- a/src/components/feed/NoteContent.tsx
+++ b/src/components/feed/NoteContent.tsx
@@ -23,7 +23,7 @@ function ImageGrid({ images, onImageClick }: { images: string[]; onImageClick: (
       <div className="mt-2">
         <img
           src={images[0]}
-          alt=""
+          alt="Posted image"
           loading="lazy"
           className="max-w-full max-h-80 rounded-sm object-cover bg-bg-raised border border-border cursor-zoom-in"
           onClick={(e) => { e.stopPropagation(); onImageClick(0); }}
@@ -40,7 +40,7 @@ function ImageGrid({ images, onImageClick }: { images: string[]; onImageClick: (
           <img
             key={idx}
             src={src}
-            alt=""
+            alt="Posted image"
             loading="lazy"
             className="w-full aspect-[4/3] rounded-sm object-cover bg-bg-raised border border-border cursor-zoom-in"
             onClick={(e) => { e.stopPropagation(); onImageClick(idx); }}
@@ -56,7 +56,7 @@ function ImageGrid({ images, onImageClick }: { images: string[]; onImageClick: (
       <div className="mt-2 grid grid-cols-2 grid-rows-2 gap-1" style={{ gridTemplateRows: "1fr 1fr" }}>
         <img
           src={visible[0]}
-          alt=""
+          alt="Posted image"
           loading="lazy"
           className="w-full h-full rounded-sm object-cover bg-bg-raised border border-border cursor-zoom-in row-span-2"
           style={{ aspectRatio: "3/4" }}
@@ -65,7 +65,7 @@ function ImageGrid({ images, onImageClick }: { images: string[]; onImageClick: (
         />
         <img
           src={visible[1]}
-          alt=""
+          alt="Posted image"
           loading="lazy"
           className="w-full aspect-[4/3] rounded-sm object-cover bg-bg-raised border border-border cursor-zoom-in"
           onClick={(e) => { e.stopPropagation(); onImageClick(1); }}
@@ -73,7 +73,7 @@ function ImageGrid({ images, onImageClick }: { images: string[]; onImageClick: (
         />
         <img
           src={visible[2]}
-          alt=""
+          alt="Posted image"
           loading="lazy"
           className="w-full aspect-[4/3] rounded-sm object-cover bg-bg-raised border border-border cursor-zoom-in"
           onClick={(e) => { e.stopPropagation(); onImageClick(2); }}
@@ -90,7 +90,7 @@ function ImageGrid({ images, onImageClick }: { images: string[]; onImageClick: (
         <div key={idx} className="relative">
           <img
             src={src}
-            alt=""
+            alt="Posted image"
             loading="lazy"
             className="w-full aspect-[4/3] rounded-sm object-cover bg-bg-raised border border-border cursor-zoom-in"
             onClick={(e) => { e.stopPropagation(); onImageClick(idx); }}
@@ -133,7 +133,7 @@ function QuotePreview({ eventId }: { eventId: string }) {
     >
       <div className="flex items-center gap-2 mb-1">
         {profile?.picture && (
-          <img src={profile.picture} alt="" className="w-4 h-4 rounded-sm object-cover shrink-0"
+          <img src={profile.picture} alt={`${name}'s avatar`} className="w-4 h-4 rounded-sm object-cover shrink-0"
             onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }} />
         )}
         <span className="text-text-muted text-[11px] font-medium truncate">{name}</span>
diff --git a/src/components/feed/QuoteModal.tsx b/src/components/feed/QuoteModal.tsx
index cec70fa..d756b45 100644
--- a/src/components/feed/QuoteModal.tsx
+++ b/src/components/feed/QuoteModal.tsx
@@ -46,13 +46,16 @@ export function QuoteModal({ event, authorName, authorAvatar, onClose, onPublish
   return (
     <div
       className="fixed inset-0 bg-black/60 flex items-center justify-center z-50"
+      role="dialog"
+      aria-modal="true"
+      aria-labelledby="quote-modal-title"
       onClick={(e) => { if (e.target === e.currentTarget) onClose(); }}
     >
       <div className="bg-bg border border-border w-full max-w-md mx-4 shadow-2xl">
         {/* Header */}
         <div className="flex items-center justify-between px-4 py-3 border-b border-border">
-          <h2 className="text-text text-sm font-medium">Quote note</h2>
-          <button onClick={onClose} className="text-text-dim hover:text-text text-lg leading-none">×</button>
+          <h2 id="quote-modal-title" className="text-text text-sm font-medium">Quote note</h2>
+          <button onClick={onClose} aria-label="Close" className="text-text-dim hover:text-text text-lg leading-none">×</button>
         </div>
 
         {/* Compose */}
@@ -72,7 +75,7 @@ export function QuoteModal({ event, authorName, authorAvatar, onClose, onPublish
           <div className="border border-border px-3 py-2.5 bg-bg-raised rounded-sm">
             <div className="flex items-center gap-2 mb-1.5">
               {authorAvatar ? (
-                <img src={authorAvatar} alt="" className="w-4 h-4 rounded-sm object-cover" />
+                <img src={authorAvatar} alt={`${authorName}'s avatar`} className="w-4 h-4 rounded-sm object-cover" />
               ) : (
                 <div className="w-4 h-4 rounded-sm bg-accent/20 flex items-center justify-center text-accent text-[8px]">
                   {authorName.charAt(0).toUpperCase()}
diff --git a/src/components/follows/FollowsView.tsx b/src/components/follows/FollowsView.tsx
index 1883cf0..5e2d484 100644
--- a/src/components/follows/FollowsView.tsx
+++ b/src/components/follows/FollowsView.tsx
@@ -34,7 +34,7 @@ function FollowRow({
         {avatar ? (
           <img
             src={avatar}
-            alt=""
+            alt={`${name}'s avatar`}
             className="w-9 h-9 rounded-sm object-cover bg-bg-raised hover:opacity-80 transition-opacity"
             loading="lazy"
             onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
diff --git a/src/components/onboarding/OnboardingFlow.tsx b/src/components/onboarding/OnboardingFlow.tsx
index 2ce3fee..2f19df4 100644
--- a/src/components/onboarding/OnboardingFlow.tsx
+++ b/src/components/onboarding/OnboardingFlow.tsx
@@ -248,6 +248,7 @@ function LoginStep({ onBack, onComplete }: { onBack: () => void; onComplete: ()
         onChange={(e) => setValue(e.target.value)}
         onKeyDown={handleKeyDown}
         placeholder={mode === "nsec" ? "nsec1…" : mode === "npub" ? "npub1…" : "bunker://…"}
+        aria-label={mode === "nsec" ? "Secret key" : mode === "npub" ? "Public key" : "Bunker URI"}
         autoFocus
         className="w-full bg-bg border border-border px-3 py-2 text-text text-[12px] font-mono focus:outline-none focus:border-accent/50 placeholder:text-text-dim mb-2"
         style={{ WebkitUserSelect: "text", userSelect: "text" } as React.CSSProperties}
diff --git a/src/components/podcast/EpisodeList.tsx b/src/components/podcast/EpisodeList.tsx
index e2d51be..cf47a7e 100644
--- a/src/components/podcast/EpisodeList.tsx
+++ b/src/components/podcast/EpisodeList.tsx
@@ -72,7 +72,7 @@ export function EpisodeList({ show, onBack }: EpisodeListProps) {
         {show.artworkUrl && (
           <img
             src={show.artworkUrl}
-            alt=""
+            alt={`${show.title || "Podcast"} artwork`}
             className="w-20 h-20 rounded-sm object-cover shrink-0"
             onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
           />
diff --git a/src/components/podcast/PodcastCard.tsx b/src/components/podcast/PodcastCard.tsx
index 4e0ebe4..774a393 100644
--- a/src/components/podcast/PodcastCard.tsx
+++ b/src/components/podcast/PodcastCard.tsx
@@ -16,7 +16,7 @@ export function PodcastCard({ show, onClick }: PodcastCardProps) {
         {show.artworkUrl ? (
           <img
             src={show.artworkUrl}
-            alt=""
+            alt={`${show.title || "Podcast"} artwork`}
             className="w-16 h-16 rounded-sm object-cover bg-bg"
             loading="lazy"
             onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
diff --git a/src/components/podcast/PodcastPlayerBar.tsx b/src/components/podcast/PodcastPlayerBar.tsx
index a99620b..d7d2b07 100644
--- a/src/components/podcast/PodcastPlayerBar.tsx
+++ b/src/components/podcast/PodcastPlayerBar.tsx
@@ -236,7 +236,7 @@ export function PodcastPlayerBar() {
         {artwork && (
           <img
             src={artwork}
-            alt=""
+            alt="Now playing artwork"
             className="w-10 h-10 rounded-sm object-cover shrink-0 bg-bg-raised"
             onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
           />
diff --git a/src/components/profile/ProfileMediaGallery.tsx b/src/components/profile/ProfileMediaGallery.tsx
index 2096cce..0c7d2df 100644
--- a/src/components/profile/ProfileMediaGallery.tsx
+++ b/src/components/profile/ProfileMediaGallery.tsx
@@ -70,7 +70,7 @@ export function ProfileMediaGallery({ notes, loading }: { notes: NDKEvent[]; loa
               >
                 <img
                   src={item.url}
-                  alt=""
+                  alt="Media content"
                   className="w-full h-full object-cover"
                   loading="lazy"
                   onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
@@ -88,7 +88,7 @@ export function ProfileMediaGallery({ notes, loading }: { notes: NDKEvent[]; loa
                 {item.thumbnailId ? (
                   <img
                     src={`https://img.youtube.com/vi/${item.thumbnailId}/mqdefault.jpg`}
-                    alt=""
+                    alt="Video thumbnail"
                     className="w-full h-full object-cover"
                     loading="lazy"
                   />
diff --git a/src/components/profile/ProfileView.tsx b/src/components/profile/ProfileView.tsx
index 778ddac..a138c65 100644
--- a/src/components/profile/ProfileView.tsx
+++ b/src/components/profile/ProfileView.tsx
@@ -28,7 +28,7 @@ function TopFollowerAvatar({ pubkey }: { pubkey: string }) {
       {profile?.picture ? (
         <img
           src={profile.picture}
-          alt=""
+          alt={`${name}'s avatar`}
           className="w-5 h-5 rounded-sm object-cover bg-bg-raised"
           onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
         />
@@ -218,7 +218,7 @@ export function ProfileView() {
                 )}
                 <img
                   src={profile.banner}
-                  alt=""
+                  alt={`${name}'s banner`}
                   className="w-full h-full object-cover object-[center_30%] cursor-pointer hover:opacity-90 transition-opacity"
                   onClick={() => setBannerLightbox(true)}
                   onLoad={() => setBannerLoaded(true)}
@@ -233,7 +233,7 @@ export function ProfileView() {
                 {avatar ? (
                   <img
                     src={avatar}
-                    alt=""
+                    alt={`${name}'s avatar`}
                     style={{ width: 64, height: 64 }}
                     className="rounded-sm object-cover bg-bg-raised"
                     onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
diff --git a/src/components/search/SearchView.tsx b/src/components/search/SearchView.tsx
index 05f73b5..c330283 100644
--- a/src/components/search/SearchView.tsx
+++ b/src/components/search/SearchView.tsx
@@ -52,21 +52,21 @@ function UserRow({ user }: { user: ParsedUser }) {
 
   return (
     <div className="flex items-center gap-3 px-4 py-2.5 border-b border-border hover:bg-bg-hover transition-colors">
-      <div className="shrink-0 cursor-pointer" onClick={() => navToProfile(user.pubkey)}>
+      <button className="shrink-0 cursor-pointer" aria-label={`View profile of ${displayName}`} onClick={() => navToProfile(user.pubkey)}>
         {user.picture ? (
-          <img src={user.picture} alt="" className="w-9 h-9 rounded-sm object-cover bg-bg-raised"
+          <img src={user.picture} alt={`${displayName}'s avatar`} className="w-9 h-9 rounded-sm object-cover bg-bg-raised"
             onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }} />
         ) : (
           <div className="w-9 h-9 rounded-sm bg-bg-raised border border-border flex items-center justify-center text-text-dim text-xs">
             {displayName.charAt(0).toUpperCase()}
           </div>
         )}
-      </div>
-      <div className="min-w-0 flex-1 cursor-pointer" onClick={() => navToProfile(user.pubkey)}>
+      </button>
+      <button className="min-w-0 flex-1 cursor-pointer text-left" onClick={() => navToProfile(user.pubkey)}>
         <div className="text-text text-[13px] font-medium truncate">{displayName}</div>
         {user.nip05 && <div className="text-text-dim text-[10px] truncate">{user.nip05}</div>}
         {user.about && <div className="text-text-dim text-[11px] truncate mt-0.5">{user.about}</div>}
-      </div>
+      </button>
       {loggedIn && !isOwn && (
         <button
           onClick={handleFollowToggle}
@@ -279,6 +279,7 @@ export function SearchView() {
             onChange={(e) => setQuery(e.target.value)}
             onKeyDown={handleKeyDown}
             placeholder="search… try by:name, #tag, has:image, is:article, since:2026-01-01"
+            aria-label="Search Nostr"
             autoFocus
             className="flex-1 bg-transparent text-text text-[13px] placeholder:text-text-dim focus:outline-none"
           />
@@ -413,17 +414,17 @@ export function SearchView() {
             )}
             {visibleSuggestions.map((s) => s.profile && (
               <div key={s.pubkey} className="flex items-center gap-3 px-4 py-2.5 border-b border-border hover:bg-bg-hover transition-colors group/suggestion">
-                <div className="shrink-0 cursor-pointer" onClick={() => useUIStore.getState().openProfile(s.pubkey)}>
+                <button className="shrink-0 cursor-pointer" aria-label={`View profile of ${s.profile.displayName || s.profile.name || "user"}`} onClick={() => useUIStore.getState().openProfile(s.pubkey)}>
                   {s.profile.picture ? (
-                    <img src={s.profile.picture} alt="" className="w-9 h-9 rounded-sm object-cover bg-bg-raised"
+                    <img src={s.profile.picture} alt={`${s.profile.displayName || s.profile.name || "User"}'s avatar`} className="w-9 h-9 rounded-sm object-cover bg-bg-raised"
                       onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }} />
                   ) : (
                     <div className="w-9 h-9 rounded-sm bg-bg-raised border border-border flex items-center justify-center text-text-dim text-xs">
                       {(s.profile.displayName || s.profile.name || "?").charAt(0).toUpperCase()}
                     </div>
                   )}
-                </div>
-                <div className="min-w-0 flex-1 cursor-pointer" onClick={() => useUIStore.getState().openProfile(s.pubkey)}>
+                </button>
+                <button className="min-w-0 flex-1 cursor-pointer text-left" onClick={() => useUIStore.getState().openProfile(s.pubkey)}>
                   <div className="text-text text-[13px] font-medium truncate">
                     {s.profile.displayName || s.profile.name || shortenPubkey(s.pubkey)}
                   </div>
@@ -434,7 +435,7 @@ export function SearchView() {
                   {s.profile.about && (
                     <div className="text-text-dim text-[11px] truncate mt-0.5">{s.profile.about}</div>
                   )}
-                </div>
+                </button>
                 <SuggestionFollowButton pubkey={s.pubkey} />
                 <button
                   onClick={() => dismiss(s.pubkey)}
diff --git a/src/components/shared/EmojiPicker.tsx b/src/components/shared/EmojiPicker.tsx
index e8c21ec..dafae75 100644
--- a/src/components/shared/EmojiPicker.tsx
+++ b/src/components/shared/EmojiPicker.tsx
@@ -18,7 +18,7 @@ export function EmojiPicker({ onSelect, onClose }: EmojiPickerProps) {
 
   return (
     <>
-      <div className="fixed inset-0 z-[9]" onClick={onClose} />
+      <div className="fixed inset-0 z-[9]" role="presentation" onClick={onClose} />
       <div className="absolute bottom-7 right-0 bg-bg-raised border border-border shadow-lg z-10 w-64">
         {/* Group tabs */}
         <div className="flex border-b border-border">
diff --git a/src/components/shared/ImageLightbox.tsx b/src/components/shared/ImageLightbox.tsx
index cc072e8..d82ecf0 100644
--- a/src/components/shared/ImageLightbox.tsx
+++ b/src/components/shared/ImageLightbox.tsx
@@ -28,11 +28,15 @@ export function ImageLightbox({ images, index, onClose, onNavigate }: ImageLight
   return (
     <div
       className="fixed inset-0 z-50 flex items-center justify-center bg-black/80 backdrop-blur-sm"
+      role="dialog"
+      aria-modal="true"
+      aria-label="Image viewer"
       onClick={onClose}
     >
       {/* Close button */}
       <button
         onClick={onClose}
+        aria-label="Close image viewer"
         className="absolute top-4 right-4 text-white/70 hover:text-white text-[20px] w-8 h-8 flex items-center justify-center transition-colors z-10"
       >
         ✕
@@ -49,6 +53,7 @@ export function ImageLightbox({ images, index, onClose, onNavigate }: ImageLight
       {hasPrev && (
         <button
           onClick={(e) => { e.stopPropagation(); onNavigate(index - 1); }}
+          aria-label="Previous image"
           className="absolute left-4 top-1/2 -translate-y-1/2 text-white/50 hover:text-white text-[28px] w-10 h-10 flex items-center justify-center transition-colors z-10"
         >
           ‹
@@ -58,7 +63,7 @@ export function ImageLightbox({ images, index, onClose, onNavigate }: ImageLight
       {/* Image */}
       <img
         src={images[index]}
-        alt=""
+        alt={`Image ${index + 1} of ${images.length}`}
         className="max-w-[90vw] max-h-[90vh] object-contain select-none"
         onClick={(e) => e.stopPropagation()}
         draggable={false}
@@ -68,6 +73,7 @@ export function ImageLightbox({ images, index, onClose, onNavigate }: ImageLight
       {hasNext && (
         <button
           onClick={(e) => { e.stopPropagation(); onNavigate(index + 1); }}
+          aria-label="Next image"
           className="absolute right-4 top-1/2 -translate-y-1/2 text-white/50 hover:text-white text-[28px] w-10 h-10 flex items-center justify-center transition-colors z-10"
         >
           ›
diff --git a/src/components/shared/LoginModal.tsx b/src/components/shared/LoginModal.tsx
index c45a5fd..80716d6 100644
--- a/src/components/shared/LoginModal.tsx
+++ b/src/components/shared/LoginModal.tsx
@@ -110,7 +110,11 @@ export function LoginModal({ onClose }: LoginModalProps) {
   return (
     <div
       className="fixed inset-0 bg-black/60 flex items-center justify-center z-50"
+      role="dialog"
+      aria-modal="true"
+      aria-labelledby="login-modal-title"
       onClick={onClose}
+      onKeyDown={(e) => { if (e.key === "Escape") onClose(); }}
     >
       <div
         className="bg-bg-raised border border-border w-full max-w-md mx-4"
@@ -118,9 +122,10 @@ export function LoginModal({ onClose }: LoginModalProps) {
       >
         {/* Header */}
         <div className="flex items-center justify-between px-4 py-3 border-b border-border">
-          <h2 className="text-text text-sm font-medium">Login</h2>
+          <h2 id="login-modal-title" className="text-text text-sm font-medium">Login</h2>
           <button
             onClick={onClose}
+            aria-label="Close login dialog"
             className="text-text-dim hover:text-text text-lg leading-none"
           >
             ×
diff --git a/src/components/shared/SettingsView.tsx b/src/components/shared/SettingsView.tsx
index 763e09f..036a095 100644
--- a/src/components/shared/SettingsView.tsx
+++ b/src/components/shared/SettingsView.tsx
@@ -27,7 +27,7 @@ function MutedRow({ pubkey, onUnmute }: { pubkey: string; onUnmute: () => void }
   return (
     <div className="flex items-center gap-3 px-3 py-2 border border-border text-[12px] group">
       {profile?.picture && (
-        <img src={profile.picture} alt="" className="w-5 h-5 rounded-sm object-cover shrink-0" />
+        <img src={profile.picture} alt={`${name}'s avatar`} className="w-5 h-5 rounded-sm object-cover shrink-0" />
       )}
       <span className="text-text truncate flex-1">{name}</span>
       <button
diff --git a/src/components/sidebar/AccountSwitcher.tsx b/src/components/sidebar/AccountSwitcher.tsx
index fe6aac0..d4a16f2 100644
--- a/src/components/sidebar/AccountSwitcher.tsx
+++ b/src/components/sidebar/AccountSwitcher.tsx
@@ -10,7 +10,7 @@ function Avatar({ account, size = "w-6 h-6", textSize = "text-[10px]" }: { accou
     return (
       <img
         src={account.picture}
-        alt=""
+        alt={`${account.name || "Account"} avatar`}
         className={`${size} rounded-sm object-cover shrink-0`}
         onError={(e) => {
           (e.target as HTMLImageElement).style.display = "none";
diff --git a/src/components/thread/AncestorChain.tsx b/src/components/thread/AncestorChain.tsx
index 1a95a27..a81ba61 100644
--- a/src/components/thread/AncestorChain.tsx
+++ b/src/components/thread/AncestorChain.tsx
@@ -21,7 +21,7 @@ function AncestorCard({ event }: { event: NDKEvent }) {
     >
       <div className="shrink-0 mt-0.5">
         {avatar ? (
-          <img src={avatar} alt="" className="w-6 h-6 rounded-sm object-cover bg-bg-raised" loading="lazy" />
+          <img src={avatar} alt={`${name}'s avatar`} className="w-6 h-6 rounded-sm object-cover bg-bg-raised" loading="lazy" />
         ) : (
           <div className="w-6 h-6 rounded-sm bg-bg-raised border border-border flex items-center justify-center text-text-dim text-[9px]">
             {name.charAt(0).toUpperCase()}
diff --git a/src/components/zap/ZapHistoryView.tsx b/src/components/zap/ZapHistoryView.tsx
index 63313f0..669eaa8 100644
--- a/src/components/zap/ZapHistoryView.tsx
+++ b/src/components/zap/ZapHistoryView.tsx
@@ -95,7 +95,7 @@ function ZapRow({
         onClick={() => pubkey && openProfile(pubkey)}
       >
         {avatar ? (
-          <img src={avatar} alt="" className="w-8 h-8 rounded-sm object-cover" loading="lazy"
+          <img src={avatar} alt={`${name}'s avatar`} className="w-8 h-8 rounded-sm object-cover" loading="lazy"
             onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }} />
         ) : (
           <div className="w-8 h-8 rounded-sm bg-bg-raised border border-border flex items-center justify-center text-text-dim text-xs">
diff --git a/src/components/zap/ZapModal.tsx b/src/components/zap/ZapModal.tsx
index e44a25d..03c9732 100644
--- a/src/components/zap/ZapModal.tsx
+++ b/src/components/zap/ZapModal.tsx
@@ -45,6 +45,9 @@ export function ZapModal({ target, recipientName, onClose }: ZapModalProps) {
   return (
     <div
       className="fixed inset-0 bg-black/60 flex items-center justify-center z-50"
+      role="dialog"
+      aria-modal="true"
+      aria-label={`Zap ${recipientName}`}
       onClick={handleBackdrop}
     >
       <div className="bg-bg border border-border w-80 shadow-2xl">
@@ -54,7 +57,7 @@ export function ZapModal({ target, recipientName, onClose }: ZapModalProps) {
             <div className="text-text text-[13px] font-medium">⚡ Zap {recipientName}</div>
             {!nwcUri && <div className="text-danger text-[10px] mt-0.5">No wallet connected</div>}
           </div>
-          <button onClick={onClose} className="text-text-dim hover:text-text text-[11px] transition-colors">✕</button>
+          <button onClick={onClose} aria-label="Close" className="text-text-dim hover:text-text text-[11px] transition-colors">✕</button>
         </div>
 
         {/* No wallet state */}