diff --git a/apps/web/src/pages/WorkspacePage.test.tsx b/apps/web/src/pages/WorkspacePage.test.tsx
index c1cf7d3..981791b 100644
--- a/apps/web/src/pages/WorkspacePage.test.tsx
+++ b/apps/web/src/pages/WorkspacePage.test.tsx
@@ -1,4 +1,4 @@
-import { act, cleanup, fireEvent, render, screen, waitFor } from '@testing-library/react';
+import { act, cleanup, fireEvent, render, screen, waitFor, within } from '@testing-library/react';
 import { MemoryRouter, Route, Routes } from 'react-router-dom';
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import { WorkspacePage } from './WorkspacePage';
@@ -7,20 +7,22 @@ const harness = vi.hoisted(() => ({
   api: { getProject: vi.fn(), listFiles: vi.fn(), latestCompile: vi.fn(), getFile: vi.fn(), createFile: vi.fn(), renameFile: vi.fn(), compile: vi.fn() },
   flush: vi.fn(async () => {}),
   user: { id: 'writer', username: 'writer', displayName: 'Writer', isAdmin: false, createdAt: '' },
+  onPresence: null as ((users: { clientId: number; name: string; color: string }[]) => void) | null,
   onEvent: null as ((event: { type: string; fileId: string }) => void) | null
 }));
 vi.mock('../lib/session', () => ({ useSession: () => ({ api: harness.api, user: harness.user, clearSession: vi.fn() }) }));
 vi.mock('../hooks/useTheme', () => ({ useTheme: () => ({ preference: 'light', resolved: 'light', setPreference: vi.fn() }) }));
 vi.mock('../hooks/useProjectEvents', () => ({ useProjectEvents: (_api: unknown, _hash: string, handler: typeof harness.onEvent) => { harness.onEvent = handler; } }));
 vi.mock('../components/PdfViewer', () => ({ PdfViewer: () => <div>PDF test preview</div> }));
-vi.mock('../components/Modal', () => ({ Modal: ({ open, children }: { open: boolean; children: import('react').ReactNode }) => open ? <div role="dialog">{children}</div> : null }));
+vi.mock('../components/Modal', () => ({ Modal: ({ open, title, onClose, children }: { open: boolean; title: string; onClose: () => void; children: import('react').ReactNode }) => open ? <div role="dialog" aria-label={title}><button onClick={onClose}>Close dialog</button>{children}</div> : null }));
 vi.mock('../components/WorkspaceDialogs', async (importOriginal) => {
   const { NewFileDialog, FileActionsDialog } = await importOriginal<typeof import('../components/WorkspaceDialogs')>();
   return { AgentDialog: () => null, CompileLogDrawer: () => null, FileActionsDialog, HistoryDrawer: () => null, NewFileDialog, ProjectSettingsDialog: () => null, ShareDialog: () => null };
 });
 vi.mock('../components/ManuscriptPane', async () => {
   const { useEffect } = await import('react');
-  return { ManuscriptPane: function Pane({ onFlushReady }: { onFlushReady: (flush: (() => Promise<void>) | null) => void }) {
+  return { ManuscriptPane: function Pane({ onFlushReady, onPresence }: { onFlushReady: (flush: (() => Promise<void>) | null) => void; onPresence: NonNullable<typeof harness.onPresence> }) {
+    useEffect(() => { harness.onPresence = onPresence; }, [onPresence]);
     useEffect(() => { onFlushReady(() => harness.flush()); return () => onFlushReady(null); }, [onFlushReady]);
     return <div>Manuscript test editor</div>;
   } };
@@ -72,6 +74,46 @@ function startFileMutation(operation: string, path: string, content: string, ren
   }
 }
 
+describe('online collaborators', () => {
+  const people = ['Alice Smith', 'Alice Stone', 'Bo', 'Charlie', 'Dana', 'Eli'].map((name, clientId) => ({ clientId, name, color: '#2583e9' }));
+
+  it('opens every full name on click, including matching initials and overflow avatars', async () => {
+    await openWorkspace();
+    act(() => harness.onPresence!(people));
+    const trigger = screen.getByRole('button', { name: "Who's online (6)" });
+    expect(trigger).toHaveAttribute('aria-haspopup', 'dialog');
+    expect(trigger).toHaveTextContent('+2');
+    expect(screen.queryByRole('dialog')).not.toBeInTheDocument();
+    fireEvent.click(trigger);
+    const list = screen.getByRole('list', { name: 'Online collaborators' });
+    expect(within(list).getAllByRole('listitem')).toHaveLength(6);
+    for (const person of people) expect(within(list).getByText(person.name)).toBeInTheDocument();
+    fireEvent.click(screen.getByRole('button', { name: 'Close dialog' }));
+    expect(screen.queryByRole('dialog')).not.toBeInTheDocument();
+  });
+
+  it('updates the open list as collaborators join and leave', async () => {
+    await openWorkspace();
+    act(() => harness.onPresence!(people.slice(0, 1)));
+    fireEvent.click(screen.getByRole('button', { name: "Who's online (1)" }));
+    act(() => harness.onPresence!(people.slice(1, 3)));
+    const list = screen.getByRole('list', { name: 'Online collaborators' });
+    expect(within(list).queryByText('Alice Smith')).not.toBeInTheDocument();
+    expect(within(list).getByText('Alice Stone')).toBeInTheDocument();
+    expect(within(list).getByText('Bo')).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: "Who's online (2)" })).toBeInTheDocument();
+    act(() => harness.onPresence!([]));
+    expect(screen.getByText('No active collaborators.')).toBeInTheDocument();
+    expect(screen.queryByRole('list')).not.toBeInTheDocument();
+  });
+
+  it('can open the empty list before presence arrives', async () => {
+    await openWorkspace();
+    fireEvent.click(screen.getByRole('button', { name: "Who's online (0)" }));
+    expect(screen.getByRole('dialog', { name: "Who's online" })).toHaveTextContent('No active collaborators.');
+  });
+});
+
 it('compiles the open file rather than the stored project default', async () => {
   harness.api.compile.mockResolvedValue({ job: { id: 'job', status: 'queued', createdAt: new Date().toISOString() } });
   await openWorkspace();
diff --git a/apps/web/src/pages/WorkspacePage.tsx b/apps/web/src/pages/WorkspacePage.tsx
index 26acb19..11ebefe 100644
--- a/apps/web/src/pages/WorkspacePage.tsx
+++ b/apps/web/src/pages/WorkspacePage.tsx
@@ -56,6 +56,7 @@ function ProjectWorkspace({ hash }: { hash: string }) {
   const [pdfError, setPdfError] = useState<string | null>(null);
   const [activity, setActivity] = useState<string | null>(null);
   const [presence, setPresence] = useState<PresenceUser[]>([]);
+  const [presenceOpen, setPresenceOpen] = useState(false);
   const [historyKey, setHistoryKey] = useState(0);
   const [treeOpen, setTreeOpen] = useState(loadTreeOpen);
   const [mobilePane, setMobilePane] = useState<'files' | 'editor' | 'pdf'>('editor');
@@ -399,7 +400,11 @@ function ProjectWorkspace({ hash }: { hash: string }) {
       <button className="icon-button workspace-back" type="button" onClick={() => navigate('/')} aria-label="Back to projects"><ArrowLeft size={17}/></button>
       <Brand subtitle={project.name} compact/>
       <div className="project-crumb"><span>{project.name}</span><small>{project.role.toUpperCase()}</small></div>
-      <div className="presence-stack" aria-label="Active collaborators">{presence.slice(0, 4).map((person) => <span key={person.clientId} className="presence-avatar" style={{ '--person-color': person.color } as React.CSSProperties} title={person.name}>{initials(person.name)}</span>)}{presence.length > 4 && <span className="presence-more">+{presence.length - 4}</span>}</div>
+      <button className="presence-trigger" type="button" aria-label={`Who's online (${presence.length})`} aria-haspopup="dialog" onClick={() => setPresenceOpen(true)}>
+        <span className="presence-stack" aria-hidden="true">{presence.slice(0, 4).map((person) => <span key={person.clientId} className="presence-avatar" style={{ '--person-color': person.color } as React.CSSProperties} title={person.name}>{initials(person.name)}</span>)}{presence.length > 4 && <span className="presence-more">+{presence.length - 4}</span>}{presence.length === 0 && <Users size={17}/>}</span>
+        <Users className="presence-mobile-icon" size={17} aria-hidden="true"/>
+        <span aria-hidden="true">{presence.length}<span className="presence-online-label"> online</span></span>
+      </button>
       {activity && <div className="live-activity"><Bot size={13}/>{activity}</div>}
       <div className="workspace-actions">
         <button className="plain-button workspace-action-text" type="button" aria-label="History" title="History" onClick={() => setHistoryOpen(true)}><History size={14}/> History</button>
@@ -453,6 +458,12 @@ function ProjectWorkspace({ hash }: { hash: string }) {
     {project.canManage && <ProjectSettingsDialog open={settingsOpen} onClose={() => setSettingsOpen(false)} api={api} project={project} onChanged={setProject} onDeleted={() => navigate('/')}/>}
     <HistoryDrawer open={historyOpen} onClose={() => setHistoryOpen(false)} api={api} projectHash={hash} file={editorMode === 'manuscript' ? files.find((file) => file.path === sourceLocation?.path) ?? selected : selected} canWrite={project.canWrite} refreshKey={historyKey}/>
     <CompileLogDrawer open={logOpen} onClose={() => setLogOpen(false)} status={job?.status ?? 'Not compiled'} log={job?.log ?? ''} error={job?.error ?? null}/>
+    <Modal open={presenceOpen} onClose={() => setPresenceOpen(false)} title="Who's online" size="small">
+      {presence.length ? <ul className="presence-list" aria-label="Online collaborators">{presence.map((person) => <li key={person.clientId}>
+        <span className="presence-avatar" style={{ '--person-color': person.color } as React.CSSProperties} aria-hidden="true">{initials(person.name)}</span>
+        <span>{person.name}</span>
+      </li>)}</ul> : <p>No active collaborators.</p>}
+    </Modal>
     <Modal open={mobileMenuOpen} onClose={() => setMobileMenuOpen(false)} title={project.name} eyebrow="Workspace actions" size="small"><div className="mobile-action-list">
       <button type="button" onClick={() => { setMobileMenuOpen(false); setHistoryOpen(true); }}><History size={16}/><span><strong>History</strong><small>Review and restore file revisions</small></span></button>
       <button type="button" onClick={() => { setMobileMenuOpen(false); setShareOpen(true); }}><Users size={16}/><span><strong>Share</strong><small>Manage project collaborators</small></span></button>
diff --git a/apps/web/src/styles.css b/apps/web/src/styles.css
index a155ab0..31405c7 100644
--- a/apps/web/src/styles.css
+++ b/apps/web/src/styles.css
@@ -252,9 +252,16 @@ button:disabled { cursor: default; opacity: .42; }
 .project-crumb span { font-size: 13px; font-weight: 600; }
 .project-crumb small { margin-top: 4px; color: var(--muted); font: 650 11px/1 var(--mono); letter-spacing: .06em; }
 .workspace-actions { min-width: 0; margin-left: auto; display: flex; align-items: center; gap: 8px; }
+.presence-trigger { min-height: 44px; flex-shrink: 0; display: flex; align-items: center; gap: 7px; padding: 0 6px; border: 0; background: transparent; color: var(--muted); font-size: 12px; cursor: pointer; }
+.presence-trigger:hover { background: var(--surface); color: var(--ink); }
+.presence-mobile-icon { display: none; }
 .presence-stack { display: flex; align-items: center; padding-left: 8px; }
 .presence-avatar, .presence-more { width: 28px; height: 28px; display: grid; place-items: center; margin-left: -7px; border: 2px solid var(--paper); border-radius: 50%; background: var(--person-color, var(--surface-2)); color: white; font: 700 11px/1 var(--sans); }
 .presence-more { background: var(--surface-2); color: var(--muted); }
+.presence-list { display: grid; gap: 16px; margin: 0; padding: 0; list-style: none; }
+.presence-list li { min-width: 0; display: flex; align-items: center; gap: 12px; overflow-wrap: anywhere; }
+.presence-list .presence-avatar { flex: 0 0 28px; margin: 0; }
+.presence-list li > span:last-child { min-width: 0; }
 .live-activity { min-width: 0; max-width: 240px; display: flex; align-items: center; gap: 6px; overflow: hidden; color: var(--accent); font: 680 11px/1 var(--mono); text-overflow: ellipsis; white-space: nowrap; }
 .compile-progress { height: 2px; background: var(--surface-2); overflow: hidden; }
 .compile-progress i { display: block; width: 0; height: 100%; background: var(--accent); }
@@ -443,6 +450,9 @@ button:disabled { cursor: default; opacity: .42; }
   .workspace-head .project-crumb span { font-size: 12px; }
   .workspace-head .project-crumb small { font-size: 10px; }
   .workspace-actions { gap: 4px; }
+  .presence-trigger { min-width: 44px; gap: 4px; }
+  .presence-mobile-icon { display: block; }
+  .presence-online-label { display: none; }
   .compile-button { min-width: 90px; height: 44px; min-height: 44px; }
   .mobile-tabs { display: grid; grid-template-columns: repeat(3, 1fr); border-bottom: 1px solid var(--line); }
   .mobile-tabs button { position: relative; display: flex; align-items: center; justify-content: center; gap: 6px; border: 0; border-radius: 0; background: var(--paper); color: var(--muted); font-size: 11px; font-weight: 700; }