diff --git a/tools/server/public/index.html.gz b/tools/server/public/index.html.gz
index 01eec46e8..02fb00339 100644
Binary files a/tools/server/public/index.html.gz and b/tools/server/public/index.html.gz differ
diff --git a/tools/server/webui/src/App.tsx b/tools/server/webui/src/App.tsx
index 3b00a8f90..1b673bbaa 100644
--- a/tools/server/webui/src/App.tsx
+++ b/tools/server/webui/src/App.tsx
@@ -28,13 +28,13 @@ function AppLayout() {
   return (
     <>
       <Sidebar />
-      <div
+      <main
         className="drawer-content grow flex flex-col h-screen w-screen mx-auto px-4 overflow-auto bg-base-100"
         id="main-scroll"
       >
         <Header />
         <Outlet />
-      </div>
+      </main>
       {
         <SettingDialog
           show={showSettings}
diff --git a/tools/server/webui/src/components/ChatInputExtraContextItem.tsx b/tools/server/webui/src/components/ChatInputExtraContextItem.tsx
index ac416fa90..4f28f8874 100644
--- a/tools/server/webui/src/components/ChatInputExtraContextItem.tsx
+++ b/tools/server/webui/src/components/ChatInputExtraContextItem.tsx
@@ -18,16 +18,26 @@ export default function ChatInputExtraContextItem({
   if (!items) return null;
 
   return (
-    <div className="flex flex-row gap-4 overflow-x-auto py-2 px-1 mb-1">
+    <div
+      className="flex flex-row gap-4 overflow-x-auto py-2 px-1 mb-1"
+      role="group"
+      aria-description="Selected files"
+    >
       {items.map((item, i) => (
         <div
           className="indicator"
           key={i}
           onClick={() => clickToShow && setShow(i)}
+          tabIndex={0}
+          aria-description={
+            clickToShow ? `Click to show: ${item.name}` : undefined
+          }
+          role={clickToShow ? 'button' : 'menuitem'}
         >
           {removeItem && (
             <div className="indicator-item indicator-top">
               <button
+                aria-label="Remove file"
                 className="btn btn-neutral btn-sm w-4 h-4 p-0 rounded-full"
                 onClick={() => removeItem(i)}
               >
@@ -46,13 +56,16 @@ export default function ChatInputExtraContextItem({
               <>
                 <img
                   src={item.base64Url}
-                  alt={item.name}
+                  alt={`Preview image for ${item.name}`}
                   className="w-14 h-14 object-cover rounded-md"
                 />
               </>
             ) : (
               <>
-                <div className="w-14 h-14 flex items-center justify-center">
+                <div
+                  className="w-14 h-14 flex items-center justify-center"
+                  aria-description="Document icon"
+                >
                   <DocumentTextIcon className="h-8 w-14 text-base-content/50" />
                 </div>
 
@@ -66,16 +79,25 @@ export default function ChatInputExtraContextItem({
       ))}
 
       {showingItem && (
-        <dialog className="modal modal-open">
+        <dialog
+          className="modal modal-open"
+          aria-description={`Preview ${showingItem.name}`}
+        >
           <div className="modal-box">
             <div className="flex justify-between items-center mb-4">
               <b>{showingItem.name ?? 'Extra content'}</b>
-              <button className="btn btn-ghost btn-sm">
+              <button
+                className="btn btn-ghost btn-sm"
+                aria-label="Close preview dialog"
+              >
                 <XMarkIcon className="h-5 w-5" onClick={() => setShow(-1)} />
               </button>
             </div>
             {showingItem.type === 'imageFile' ? (
-              <img src={showingItem.base64Url} alt={showingItem.name} />
+              <img
+                src={showingItem.base64Url}
+                alt={`Preview image for ${showingItem.name}`}
+              />
             ) : (
               <div className="overflow-x-auto">
                 <pre className="whitespace-pre-wrap break-words text-sm">
diff --git a/tools/server/webui/src/components/ChatMessage.tsx b/tools/server/webui/src/components/ChatMessage.tsx
index 08eb42352..ee59de450 100644
--- a/tools/server/webui/src/components/ChatMessage.tsx
+++ b/tools/server/webui/src/components/ChatMessage.tsx
@@ -83,13 +83,20 @@ export default function ChatMessage({
 
   if (!viewingChat) return null;
 
+  const isUser = msg.role === 'user';
+
   return (
-    <div className="group" id={id}>
+    <div
+      className="group"
+      id={id}
+      role="group"
+      aria-description={`Message from ${msg.role}`}
+    >
       <div
         className={classNames({
           chat: true,
-          'chat-start': msg.role !== 'user',
-          'chat-end': msg.role === 'user',
+          'chat-start': !isUser,
+          'chat-end': isUser,
         })}
       >
         {msg.extra && msg.extra.length > 0 && (
@@ -99,7 +106,7 @@ export default function ChatMessage({
         <div
           className={classNames({
             'chat-bubble markdown': true,
-            'chat-bubble bg-transparent': msg.role !== 'user',
+            'chat-bubble bg-transparent': !isUser,
           })}
         >
           {/* textarea for editing message */}
@@ -142,7 +149,7 @@ export default function ChatMessage({
               ) : (
                 <>
                   {/* render message as markdown */}
-                  <div dir="auto">
+                  <div dir="auto" tabIndex={0}>
                     {thought && (
                       <ThoughtProcess
                         isThinking={!!isThinking && !!isPending}
@@ -196,13 +203,18 @@ export default function ChatMessage({
           })}
         >
           {siblingLeafNodeIds && siblingLeafNodeIds.length > 1 && (
-            <div className="flex gap-1 items-center opacity-60 text-sm">
+            <div
+              className="flex gap-1 items-center opacity-60 text-sm"
+              role="navigation"
+              aria-description={`Message version ${siblingCurrIdx + 1} of ${siblingLeafNodeIds.length}`}
+            >
               <button
                 className={classNames({
                   'btn btn-sm btn-ghost p-1': true,
                   'opacity-20': !prevSibling,
                 })}
                 onClick={() => prevSibling && onChangeSibling(prevSibling)}
+                aria-label="Previous message version"
               >
                 <ChevronLeftIcon className="h-4 w-4" />
               </button>
@@ -215,6 +227,7 @@ export default function ChatMessage({
                   'opacity-20': !nextSibling,
                 })}
                 onClick={() => nextSibling && onChangeSibling(nextSibling)}
+                aria-label="Next message version"
               >
                 <ChevronRightIcon className="h-4 w-4" />
               </button>
@@ -223,7 +236,7 @@ export default function ChatMessage({
           {/* user message */}
           {msg.role === 'user' && (
             <BtnWithTooltips
-              className="btn-mini show-on-hover w-8 h-8"
+              className="btn-mini w-8 h-8"
               onClick={() => setEditingContent(msg.content)}
               disabled={msg.content === null}
               tooltipsContent="Edit message"
@@ -236,7 +249,7 @@ export default function ChatMessage({
             <>
               {!isPending && (
                 <BtnWithTooltips
-                  className="btn-mini show-on-hover w-8 h-8"
+                  className="btn-mini w-8 h-8"
                   onClick={() => {
                     if (msg.content !== null) {
                       onRegenerateMessage(msg as Message);
@@ -250,10 +263,7 @@ export default function ChatMessage({
               )}
             </>
           )}
-          <CopyButton
-            className="btn-mini show-on-hover w-8 h-8"
-            content={msg.content}
-          />
+          <CopyButton className="btn-mini w-8 h-8" content={msg.content} />
         </div>
       )}
     </div>
@@ -271,6 +281,8 @@ function ThoughtProcess({
 }) {
   return (
     <div
+      role="button"
+      aria-label="Toggle thought process display"
       tabIndex={0}
       className={classNames({
         'collapse bg-none': true,
@@ -292,7 +304,11 @@ function ThoughtProcess({
           )}
         </div>
       </div>
-      <div className="collapse-content text-base-content/70 text-sm p-1">
+      <div
+        className="collapse-content text-base-content/70 text-sm p-1"
+        tabIndex={0}
+        aria-description="Thought process content"
+      >
         <div className="border-l-2 border-base-content/20 pl-4 mb-4">
           <MarkdownDisplay content={content} />
         </div>
diff --git a/tools/server/webui/src/components/ChatScreen.tsx b/tools/server/webui/src/components/ChatScreen.tsx
index 661fe1490..09c601ef2 100644
--- a/tools/server/webui/src/components/ChatScreen.tsx
+++ b/tools/server/webui/src/components/ChatScreen.tsx
@@ -279,7 +279,11 @@ export default function ChatScreen() {
 function ServerInfo() {
   const { serverProps } = useAppContext();
   return (
-    <div className="card card-sm shadow-sm border-1 border-base-content/20 text-base-content/70 mb-6">
+    <div
+      className="card card-sm shadow-sm border-1 border-base-content/20 text-base-content/70 mb-6"
+      tabIndex={0}
+      aria-description="Server information"
+    >
       <div className="card-body">
         <b>Server Info</b>
         <p>
@@ -311,6 +315,8 @@ function ChatInput({
 
   return (
     <div
+      role="group"
+      aria-label="Chat input"
       className={classNames({
         'flex items-end pt-8 pb-6 sticky bottom-0 bg-base-100': true,
         'opacity-50': isDrag, // simply visual feedback to inform user that the file will be accepted
@@ -400,13 +406,15 @@ function ChatInput({
                     'btn w-8 h-8 p-0 rounded-full': true,
                     'btn-disabled': isGenerating,
                   })}
+                  aria-label="Upload file"
+                  tabIndex={0}
+                  role="button"
                 >
                   <PaperClipIcon className="h-5 w-5" />
                 </label>
                 <input
                   id="file-upload"
                   type="file"
-                  className="hidden"
                   disabled={isGenerating}
                   {...getInputProps()}
                   hidden
@@ -422,6 +430,7 @@ function ChatInput({
                   <button
                     className="btn btn-primary w-8 h-8 p-0 rounded-full"
                     onClick={onSend}
+                    aria-label="Send message"
                   >
                     <ArrowUpIcon className="h-5 w-5" />
                   </button>
diff --git a/tools/server/webui/src/components/Header.tsx b/tools/server/webui/src/components/Header.tsx
index 45775ff7a..ccddc21dd 100644
--- a/tools/server/webui/src/components/Header.tsx
+++ b/tools/server/webui/src/components/Header.tsx
@@ -38,8 +38,12 @@ export default function Header() {
 
       {/* action buttons (top right) */}
       <div className="flex items-center">
-        <div className="tooltip tooltip-bottom" data-tip="Settings">
-          <button className="btn" onClick={() => setShowSettings(true)}>
+        <div
+          className="tooltip tooltip-bottom"
+          data-tip="Settings"
+          onClick={() => setShowSettings(true)}
+        >
+          <button className="btn" aria-hidden={true}>
             {/* settings button */}
             <Cog8ToothIcon className="w-5 h-5" />
           </button>
diff --git a/tools/server/webui/src/components/SettingDialog.tsx b/tools/server/webui/src/components/SettingDialog.tsx
index 0240a17f4..e4684be7e 100644
--- a/tools/server/webui/src/components/SettingDialog.tsx
+++ b/tools/server/webui/src/components/SettingDialog.tsx
@@ -335,14 +335,22 @@ export default function SettingDialog({
   };
 
   return (
-    <dialog className={classNames({ modal: true, 'modal-open': show })}>
+    <dialog
+      className={classNames({ modal: true, 'modal-open': show })}
+      aria-label="Settings dialog"
+    >
       <div className="modal-box w-11/12 max-w-3xl">
         <h3 className="text-lg font-bold mb-6">Settings</h3>
         <div className="flex flex-col md:flex-row h-[calc(90vh-12rem)]">
           {/* Left panel, showing sections - Desktop version */}
-          <div className="hidden md:flex flex-col items-stretch pr-4 mr-4 border-r-2 border-base-200">
+          <div
+            className="hidden md:flex flex-col items-stretch pr-4 mr-4 border-r-2 border-base-200"
+            role="complementary"
+            aria-description="Settings sections"
+            tabIndex={0}
+          >
             {SETTING_SECTIONS.map((section, idx) => (
-              <div
+              <button
                 key={idx}
                 className={classNames({
                   'btn btn-ghost justify-start font-normal w-44 mb-1': true,
@@ -352,12 +360,16 @@ export default function SettingDialog({
                 dir="auto"
               >
                 {section.title}
-              </div>
+              </button>
             ))}
           </div>
 
           {/* Left panel, showing sections - Mobile version */}
-          <div className="md:hidden flex flex-row gap-2 mb-4">
+          {/* This menu is skipped on a11y, otherwise it's repeated the desktop version */}
+          <div
+            className="md:hidden flex flex-row gap-2 mb-4"
+            aria-disabled={true}
+          >
             <details className="dropdown">
               <summary className="btn bt-sm w-full m-1">
                 {SETTING_SECTIONS[sectionIdx].title}
diff --git a/tools/server/webui/src/components/Sidebar.tsx b/tools/server/webui/src/components/Sidebar.tsx
index 8e79e00b8..8cac52f4c 100644
--- a/tools/server/webui/src/components/Sidebar.tsx
+++ b/tools/server/webui/src/components/Sidebar.tsx
@@ -50,44 +50,72 @@ export default function Sidebar() {
         id="toggle-drawer"
         type="checkbox"
         className="drawer-toggle"
+        aria-label="Toggle sidebar"
         defaultChecked
       />
 
-      <div className="drawer-side h-screen lg:h-screen z-50 lg:max-w-64">
+      <div
+        className="drawer-side h-screen lg:h-screen z-50 lg:max-w-64"
+        role="complementary"
+        aria-label="Sidebar"
+        tabIndex={0}
+      >
         <label
           htmlFor="toggle-drawer"
-          aria-label="close sidebar"
+          aria-label="Close sidebar"
           className="drawer-overlay"
         ></label>
+
+        <a
+          href="#main-scroll"
+          className="absolute -left-80 top-0 w-1 h-1 overflow-hidden"
+        >
+          Skip to main content
+        </a>
+
         <div className="flex flex-col bg-base-200 min-h-full max-w-64 py-4 px-4">
           <div className="flex flex-row items-center justify-between mb-4 mt-4">
-            <h2 className="font-bold ml-4">Conversations</h2>
+            <h2 className="font-bold ml-4" role="heading">
+              Conversations
+            </h2>
 
             {/* close sidebar button */}
-            <label htmlFor="toggle-drawer" className="btn btn-ghost lg:hidden">
+            <label
+              htmlFor="toggle-drawer"
+              className="btn btn-ghost lg:hidden"
+              aria-label="Close sidebar"
+              role="button"
+              tabIndex={0}
+            >
               <XMarkIcon className="w-5 h-5" />
             </label>
           </div>
 
           {/* new conversation button */}
-          <div
+          <button
             className={classNames({
               'btn btn-ghost justify-start px-2': true,
               'btn-soft': !currConv,
             })}
             onClick={() => navigate('/')}
+            aria-label="New conversation"
           >
             <PencilSquareIcon className="w-5 h-5" />
             New conversation
-          </div>
+          </button>
 
           {/* list of conversations */}
           {groupedConv.map((group, i) => (
-            <div key={i}>
+            <div key={i} role="group">
               {/* group name (by date) */}
               {group.title ? (
                 // we use btn class here to make sure that the padding/margin are aligned with the other items
-                <b className="btn btn-ghost btn-xs bg-none btn-disabled block text-xs text-base-content text-start px-2 mb-0 mt-6 font-bold">
+                <b
+                  className="btn btn-ghost btn-xs bg-none btn-disabled block text-xs text-base-content text-start px-2 mb-0 mt-6 font-bold"
+                  role="note"
+                  aria-description={group.title}
+                  tabIndex={0}
+                >
                   {group.title}
                 </b>
               ) : (
@@ -184,20 +212,23 @@ function ConversationItem({
 }) {
   return (
     <div
+      role="menuitem"
+      tabIndex={0}
+      aria-label={conv.name}
       className={classNames({
         'group flex flex-row btn btn-ghost justify-start items-center font-normal px-2 h-9':
           true,
         'btn-soft': isCurrConv,
       })}
     >
-      <div
+      <button
         key={conv.id}
         className="w-full overflow-hidden truncate text-start"
         onClick={onSelect}
         dir="auto"
       >
         {conv.name}
-      </div>
+      </button>
       <div className="dropdown dropdown-end h-5">
         <BtnWithTooltips
           // on mobile, we always show the ellipsis icon
@@ -211,22 +242,23 @@ function ConversationItem({
         </BtnWithTooltips>
         {/* dropdown menu */}
         <ul
+          aria-label="More options"
           tabIndex={0}
           className="dropdown-content menu bg-base-100 rounded-box z-[1] p-2 shadow"
         >
-          <li onClick={onRename}>
+          <li onClick={onRename} tabIndex={0}>
             <a>
               <PencilIcon className="w-4 h-4" />
               Rename
             </a>
           </li>
-          <li onClick={onDownload}>
+          <li onClick={onDownload} tabIndex={0}>
             <a>
               <ArrowDownTrayIcon className="w-4 h-4" />
               Download
             </a>
           </li>
-          <li className="text-error" onClick={onDelete}>
+          <li className="text-error" onClick={onDelete} tabIndex={0}>
             <a>
               <TrashIcon className="w-4 h-4" />
               Delete
diff --git a/tools/server/webui/src/index.scss b/tools/server/webui/src/index.scss
index 563e7a461..64460b740 100644
--- a/tools/server/webui/src/index.scss
+++ b/tools/server/webui/src/index.scss
@@ -34,9 +34,6 @@ html {
   /* TODO: fix markdown table */
 }
 
-.show-on-hover {
-  @apply md:opacity-0 md:group-hover:opacity-100;
-}
 .btn-mini {
   @apply cursor-pointer;
 }
diff --git a/tools/server/webui/src/utils/common.tsx b/tools/server/webui/src/utils/common.tsx
index 372f464a2..7dd64508a 100644
--- a/tools/server/webui/src/utils/common.tsx
+++ b/tools/server/webui/src/utils/common.tsx
@@ -52,13 +52,20 @@ export function BtnWithTooltips({
   tooltipsContent: string;
   disabled?: boolean;
 }) {
+  // the onClick handler is on the container, so screen readers can safely ignore the inner button
+  // this prevents the label from being read twice
   return (
-    <div className="tooltip tooltip-bottom" data-tip={tooltipsContent}>
+    <div
+      className="tooltip tooltip-bottom"
+      data-tip={tooltipsContent}
+      role="button"
+      onClick={onClick}
+    >
       <button
         className={`${className ?? ''} flex items-center justify-center`}
-        onClick={onClick}
         disabled={disabled}
         onMouseLeave={onMouseLeave}
+        aria-hidden={true}
       >
         {children}
       </button>