diff --git a/src/components/WelcomeDialog.vue b/src/components/WelcomeDialog.vue
index dbc73f3..301351d 100644
--- a/src/components/WelcomeDialog.vue
+++ b/src/components/WelcomeDialog.vue
@@ -1,6 +1,8 @@
 <script setup lang="ts">
 import { nextTick, onMounted, ref, watch } from 'vue'
 import {
+  PhArchive,
+  PhArrowsClockwise,
   PhFileArrowUp,
   PhFolderOpen,
   PhPlus,
@@ -9,9 +11,16 @@ import {
 import ruwioLogo from '@/assets/logo.png'
 import {
   deleteStoredProject,
+  listAllProjects,
   listRecentProjects,
+  saveProjectToStore,
   type StoredProject,
 } from '@/lib/projectStore'
+import {
+  downloadBackup,
+  pickBackupFile,
+  readBackupFile,
+} from '@/lib/backupFile'
 import { confirmDialog, Modal } from '@/components/ui'
 import { t } from '@/i18n'
 
@@ -149,6 +158,90 @@ function importFile() {
   emit('update:modelValue', false)
 }
 
+const backupBusy = ref(false)
+const backupError = ref<string | null>(null)
+
+/** Dump every project in IDB into a single .ruwbak file. No-ops
+ *  with a friendly toast when the store is empty — users expect a
+ *  signal, not a mystery zero-byte file. */
+async function backupAll() {
+  if (backupBusy.value) return
+  backupBusy.value = true
+  backupError.value = null
+  try {
+    const all = await listAllProjects()
+    const records = all
+      .filter((r) => !!r.project)
+      .map((r) => ({
+        id: r.id,
+        name: r.name,
+        savedAt: r.savedAt,
+        thumbnail: r.thumbnail,
+        project: r.project!,
+      }))
+    if (!records.length) {
+      backupError.value = t('welcome.backupEmpty')
+      return
+    }
+    downloadBackup(records)
+  } catch (err) {
+    backupError.value =
+      err instanceof Error ? err.message : String(err)
+  } finally {
+    backupBusy.value = false
+  }
+}
+
+/** Pick a .ruwbak file and write every project it contains into
+ *  IDB, preserving ids so the next save overwrites cleanly. The
+ *  existing recents list is NOT cleared — users typically want to
+ *  merge rather than wipe, and we want the opportunity to refuse
+ *  a confusing clobber. */
+async function restoreBackup() {
+  if (backupBusy.value) return
+  const file = await pickBackupFile()
+  if (!file) return
+  backupBusy.value = true
+  backupError.value = null
+  try {
+    const records = await readBackupFile(file)
+    if (records.length === 0) {
+      backupError.value = t('welcome.backupEmpty')
+      return
+    }
+    // Check for id collisions so the user knows they'll be
+    // overwriting existing projects before we start writing.
+    const existing = await listAllProjects()
+    const existingIds = new Set(existing.map((r) => r.id))
+    const overlaps = records.filter((r) => existingIds.has(r.id)).length
+    if (overlaps > 0) {
+      const ok = await confirmDialog({
+        title: t('welcome.restoreConfirmTitle'),
+        message: t('welcome.restoreConfirmMessage', {
+          total: records.length,
+          overlap: overlaps,
+        }),
+        confirmLabel: t('welcome.restoreConfirmButton'),
+        variant: 'danger',
+      })
+      if (!ok) return
+    }
+    for (const rec of records) {
+      await saveProjectToStore(rec.project, {
+        id: rec.id,
+        name: rec.name,
+        thumbnail: rec.thumbnail,
+      })
+    }
+    await reload()
+  } catch (err) {
+    backupError.value =
+      err instanceof Error ? err.message : String(err)
+  } finally {
+    backupBusy.value = false
+  }
+}
+
 function close() {
   emit('update:modelValue', false)
 }
@@ -219,6 +312,7 @@ watch(
               </li>
             </ul>
     </div>
+    <div v-if="backupError" class="backup-error">{{ backupError }}</div>
     <template #footer>
       <button ref="newBtnRef" class="ftr-btn" @click="startFresh">
         <PhPlus :size="13" weight="bold" />
@@ -228,6 +322,25 @@ watch(
         <PhFileArrowUp :size="13" />
         {{ t('welcome.importFile') }}
       </button>
+      <span class="ftr-sep"></span>
+      <button
+        class="ftr-btn"
+        :disabled="backupBusy"
+        v-tooltip="t('welcome.backupAllHelp')"
+        @click="backupAll"
+      >
+        <PhArchive :size="13" />
+        {{ t('welcome.backupAll') }}
+      </button>
+      <button
+        class="ftr-btn"
+        :disabled="backupBusy"
+        v-tooltip="t('welcome.restoreBackupHelp')"
+        @click="restoreBackup"
+      >
+        <PhArrowsClockwise :size="13" />
+        {{ t('welcome.restoreBackup') }}
+      </button>
     </template>
   </Modal>
 </template>
@@ -389,4 +502,22 @@ watch(
   border-color: var(--accent);
   box-shadow: 0 0 0 2px var(--accent-soft);
 }
+
+.ftr-btn:disabled {
+  opacity: 0.5;
+  cursor: default;
+}
+
+.ftr-sep {
+  flex: 1;
+}
+
+.backup-error {
+  margin: 0 12px 8px;
+  padding: 8px 10px;
+  font-size: 11px;
+  background: var(--danger-soft);
+  color: var(--danger);
+  border-radius: var(--radius-sm);
+}
 </style>
diff --git a/src/devtools/tests.ts b/src/devtools/tests.ts
index f770c74..b13c410 100644
--- a/src/devtools/tests.ts
+++ b/src/devtools/tests.ts
@@ -1943,6 +1943,102 @@ export function registerAllTests(): void {
     })
   })
 
+  suite('ruwbak — multi-project backup roundtrip', () => {
+    // A .ruwbak is a zip holding one manifest.json + one packaged
+    // .ruw per project. Covers the "back up everything in browser
+    // storage" / "restore a backup" flow exposed from the welcome
+    // dialog.
+
+    test('pack + unpack preserves each project with its metadata', async () => {
+      const { packBackup, unpackBackup } = await import('@/lib/backupFile')
+      const a = makeFreshStore()
+      a.addAsset({ kind: 'rect', name: 'A', width: 10, height: 10, fill: '#000' })
+      const projectA = JSON.parse(JSON.stringify(a.projectForSave))
+      const b = makeFreshStore()
+      b.addAsset({ kind: 'rect', name: 'B', width: 20, height: 20, fill: '#fff' })
+      const projectB = JSON.parse(JSON.stringify(b.projectForSave))
+      const bundle = packBackup([
+        { id: 'id-a', name: 'Alpha', savedAt: 1, project: projectA },
+        { id: 'id-b', name: 'Beta', savedAt: 2, project: projectB },
+      ])
+      const out = unpackBackup(bundle)
+      expect(out.length).toBe(2)
+      expect(out[0].id).toBe('id-a')
+      expect(out[0].name).toBe('Alpha')
+      expect(out[0].savedAt).toBe(1)
+      expect(out[0].project.assets.some((x) => x.name === 'A')).toBe(true)
+      expect(out[1].id).toBe('id-b')
+      expect(out[1].project.assets.some((x) => x.name === 'B')).toBe(true)
+    })
+
+    test('backup survives asset data through the inner .ruw bundles', async () => {
+      const { packBackup, unpackBackup } = await import('@/lib/backupFile')
+      const s = makeFreshStore()
+      const imgSrc = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEX///+nxBvIAAAAC0lEQVQI12NgAAIAAAUAAeImBZsAAAAASUVORK5CYII='
+      s.addAsset({
+        kind: 'image', name: 'pixel', src: imgSrc, width: 1, height: 1,
+      })
+      const project = JSON.parse(JSON.stringify(s.projectForSave))
+      const bundle = packBackup([
+        { id: 'only', name: 'Sole', savedAt: 0, project },
+      ])
+      const [rec] = unpackBackup(bundle)
+      const img = rec.project.assets.find((a) => a.name === 'pixel')! as {
+        src: string
+      }
+      // Image round-trips all the way: through inner .ruw asset
+      // extraction + rehydration via the outer backup zip.
+      expect(img.src).toBe(imgSrc)
+    })
+
+    test('unpackBackup rejects non-zip + wrong magic + missing files', async () => {
+      const { unpackBackup, packBackup } = await import('@/lib/backupFile')
+      // Non-zip input.
+      let err: unknown
+      try { unpackBackup(new Uint8Array([0x7b, 0x7d])) } catch (e) { err = e }
+      expect((err as Error).message).toContain('ZIP')
+      // Wrong-magic manifest.
+      const { zipStore } = await import('@/lib/zipUtil')
+      const badManifest = zipStore([{
+        name: 'manifest.json',
+        data: new TextEncoder().encode(JSON.stringify({ magic: 'nope', version: 1, projects: [] })),
+      }])
+      err = null
+      try { unpackBackup(badManifest) } catch (e) { err = e }
+      expect((err as Error).message.toLowerCase()).toContain('magic')
+      // Missing referenced project file.
+      const s = makeFreshStore()
+      s.addAsset({ kind: 'rect', name: 'X', width: 10, height: 10, fill: '#fff' })
+      const goodBundle = packBackup([
+        { id: 'missing', name: 'Lost', savedAt: 1, project: JSON.parse(JSON.stringify(s.projectForSave)) },
+      ])
+      // Strip the inner .ruw to simulate corruption.
+      const { unzipStore } = await import('@/lib/zipUtil')
+      const entries = unzipStore(goodBundle).filter(
+        (e) => !e.name.startsWith('projects/'),
+      )
+      const corrupt = zipStore(entries)
+      err = null
+      try { unpackBackup(corrupt) } catch (e) { err = e }
+      expect((err as Error).message.toLowerCase()).toContain('missing')
+    })
+
+    test('duplicate ids in the input get unique file paths inside the zip', async () => {
+      const { packBackup } = await import('@/lib/backupFile')
+      const { unzipStore } = await import('@/lib/zipUtil')
+      const s = makeFreshStore()
+      s.addAsset({ kind: 'rect', name: 'X', width: 10, height: 10, fill: '#fff' })
+      const project = JSON.parse(JSON.stringify(s.projectForSave))
+      const bundle = packBackup([
+        { id: 'dup', name: 'A', savedAt: 1, project },
+        { id: 'dup', name: 'B', savedAt: 2, project },
+      ])
+      const files = unzipStore(bundle).map((e) => e.name).filter((n) => n.startsWith('projects/'))
+      // Two distinct project files, one suffixed to avoid collision.
+      expect(new Set(files).size).toBe(2)
+    })
+  })
+
   suite('editor state — save / load roundtrip', () => {
     // The store's editor block carries canvas zoom/pan, overlay
     // toggles and timeline display settings. It rides along with the
@@ -2842,6 +2938,29 @@ export function registerAllTests(): void {
       const back = await getStoredProject('definitely-missing-id-42')
       expect(back).toBeNull()
     })
+
+    test('listAllProjects returns every record — no 8-recents cap', async () => {
+      // Backup flow needs the full dump, not just the top 8 that
+      // the welcome dialog shows.
+      const { listAllProjects } = await import('@/lib/projectStore')
+      const s = makeFreshStore()
+      const ids: string[] = []
+      const prefix = `test-backup-${Date.now()}-`
+      for (let i = 0; i < 10; i++) ids.push(`${prefix}${i}`)
+      try {
+        for (const id of ids) {
+          await saveProjectToStore(s.project, { id, name: id })
+          await tick(1)
+        }
+        const all = await listAllProjects()
+        // At least our 10 show up, even though listRecentProjects
+        // would only return 8.
+        const seen = ids.filter((id) => all.some((r) => r.id === id))
+        expect(seen.length).toBe(10)
+      } finally {
+        for (const id of ids) await deleteStoredProject(id).catch(() => {})
+      }
+    })
   })
 
   suite('ui — WelcomeDialog', () => {
diff --git a/src/i18n/messages.ts b/src/i18n/messages.ts
index 5578d76..1caf36b 100644
--- a/src/i18n/messages.ts
+++ b/src/i18n/messages.ts
@@ -58,6 +58,14 @@ export const en = {
       message: '"{name}" will be permanently removed from browser storage.',
       confirm: 'Delete',
     },
+    backupAll: 'Backup all…',
+    backupAllHelp: 'Save every project in browser storage into a single .ruwbak file.',
+    backupEmpty: 'No saved projects yet — nothing to back up.',
+    restoreBackup: 'Restore backup…',
+    restoreBackupHelp: 'Load every project from a .ruwbak file into browser storage.',
+    restoreConfirmTitle: 'Restore backup?',
+    restoreConfirmMessage: 'Writing {total} projects — {overlap} of them would overwrite projects already in browser storage with the same id.',
+    restoreConfirmButton: 'Overwrite and restore',
   },
 
   sidebar: {
diff --git a/src/lib/backupFile.ts b/src/lib/backupFile.ts
new file mode 100644
index 0000000..fe6ee8e
--- /dev/null
+++ b/src/lib/backupFile.ts
@@ -0,0 +1,166 @@
+/**
+ * Multi-project backup bundle. Packs every StoredProject in IDB into
+ * one zip with an outer manifest and each project re-serialised as
+ * its own inner .ruw bundle:
+ *
+ *   backup.zip
+ *     manifest.json  — { magic: 'ruwio-backup', version: 1,
+ *                        projects: [{ id, name, savedAt,
+ *                          thumbnail?, file: 'projects/<id>.ruw' }] }
+ *     projects/<id>.ruw  — normal single-project bundle
+ *                          (reusable standalone if the user
+ *                          extracts it).
+ *
+ * Nested zips cost a bit of overhead but buy a clean boundary: each
+ * inner .ruw stays a valid round-trippable project that the welcome
+ * dialog / file picker can import on its own. Extracting the backup
+ * gives the user a tidy folder of independent projects rather than
+ * one bucket of tangled assets.
+ */
+
+import type { Project } from '@/types/scene'
+import { looksLikeZip, unzipStore, zipStore, type ZipEntry } from './zipUtil'
+import { packProject, unpackProject } from './ruwFile'
+
+const BACKUP_MAGIC = 'ruwio-backup'
+const BACKUP_VERSION = 1
+const PROJECTS_DIR = 'projects/'
+
+export interface BackupRecord {
+  id: string
+  name: string
+  savedAt: number
+  thumbnail?: string
+  project: Project
+}
+
+interface BackupManifestEntry {
+  id: string
+  name: string
+  savedAt: number
+  thumbnail?: string
+  file: string
+}
+
+interface BackupManifest {
+  magic: typeof BACKUP_MAGIC
+  version: number
+  savedAt: string
+  projects: BackupManifestEntry[]
+}
+
+/** Pack every provided record into a single backup zip. Returns the
+ *  raw bytes; callers download via `downloadBackup`. */
+export function packBackup(records: BackupRecord[]): Uint8Array {
+  const entries: ZipEntry[] = []
+  const manifest: BackupManifest = {
+    magic: BACKUP_MAGIC,
+    version: BACKUP_VERSION,
+    savedAt: new Date().toISOString(),
+    projects: [],
+  }
+  const used = new Set<string>()
+  for (const rec of records) {
+    // Guard against id collisions (shouldn't happen from IDB but we
+    // accept arbitrary input) — suffix duplicates so zip paths stay
+    // unique.
+    let fileId = rec.id
+    let i = 2
+    while (used.has(fileId)) {
+      fileId = `${rec.id}-${i++}`
+    }
+    used.add(fileId)
+    const file = `${PROJECTS_DIR}${fileId}.ruw`
+    entries.push({ name: file, data: packProject(rec.project) })
+    manifest.projects.push({
+      id: rec.id,
+      name: rec.name,
+      savedAt: rec.savedAt,
+      thumbnail: rec.thumbnail,
+      file,
+    })
+  }
+  entries.unshift({
+    name: 'manifest.json',
+    data: new TextEncoder().encode(JSON.stringify(manifest, null, 2)),
+  })
+  return zipStore(entries)
+}
+
+/** Reverse of `packBackup`. Throws if the file isn't a RUWIO backup
+ *  or an entry referenced by the manifest is missing / corrupt. */
+export function unpackBackup(bytes: Uint8Array): BackupRecord[] {
+  if (!looksLikeZip(bytes)) {
+    throw new Error('Not a RUWIO backup (missing ZIP signature).')
+  }
+  const entries = unzipStore(bytes)
+  const byName = new Map<string, Uint8Array>()
+  for (const e of entries) byName.set(e.name, e.data)
+  const manifestBytes = byName.get('manifest.json')
+  if (!manifestBytes) {
+    throw new Error('Backup is missing manifest.json.')
+  }
+  let manifest: BackupManifest
+  try {
+    manifest = JSON.parse(new TextDecoder().decode(manifestBytes)) as BackupManifest
+  } catch {
+    throw new Error('Backup manifest is not valid JSON.')
+  }
+  if (manifest.magic !== BACKUP_MAGIC) {
+    throw new Error('Manifest magic does not match — is this a RUWIO backup?')
+  }
+  if (!Array.isArray(manifest.projects)) {
+    throw new Error('Backup manifest is missing the projects list.')
+  }
+  const out: BackupRecord[] = []
+  for (const entry of manifest.projects) {
+    const file = byName.get(entry.file)
+    if (!file) {
+      throw new Error(`Backup is missing project file "${entry.file}".`)
+    }
+    const project = unpackProject(file)
+    out.push({
+      id: entry.id,
+      name: entry.name,
+      savedAt: entry.savedAt,
+      thumbnail: entry.thumbnail,
+      project,
+    })
+  }
+  return out
+}
+
+export function downloadBackup(
+  records: BackupRecord[],
+  filename = `ruwio-backup-${new Date().toISOString().replace(/[:.]/g, '-')}.ruwbak`,
+): void {
+  const bytes = packBackup(records)
+  const copy = new Uint8Array(bytes.byteLength)
+  copy.set(bytes)
+  const blob = new Blob([copy], { type: 'application/zip' })
+  const url = URL.createObjectURL(blob)
+  const a = document.createElement('a')
+  a.href = url
+  a.download = filename
+  document.body.appendChild(a)
+  a.click()
+  document.body.removeChild(a)
+  setTimeout(() => URL.revokeObjectURL(url), 1000)
+}
+
+export async function readBackupFile(file: File): Promise<BackupRecord[]> {
+  const buf = new Uint8Array(await file.arrayBuffer())
+  return unpackBackup(buf)
+}
+
+/** File-picker tuned for `.ruwbak` plus a zip fallback. */
+export function pickBackupFile(): Promise<File | null> {
+  return new Promise((resolve) => {
+    const input = document.createElement('input')
+    input.type = 'file'
+    input.accept = '.ruwbak,application/zip'
+    input.onchange = () => resolve(input.files?.[0] ?? null)
+    input.oncancel = () => resolve(null)
+    input.click()
+  })
+}
diff --git a/src/lib/projectStore.ts b/src/lib/projectStore.ts
index 1519916..8293049 100644
--- a/src/lib/projectStore.ts
+++ b/src/lib/projectStore.ts
@@ -76,6 +76,21 @@ export async function listRecentProjects(): Promise<StoredProject[]> {
   }
 }
 
+/** Full IDB dump — every stored project, newest first, no recents
+ *  cap. Used by the "backup all" flow; the welcome list sticks to
+ *  `listRecentProjects` so the UI stays short. */
+export async function listAllProjects(): Promise<StoredProject[]> {
+  try {
+    const all = await tx<StoredProject[]>('readonly', (s) => s.getAll() as IDBRequest<StoredProject[]>)
+    return (all ?? [])
+      .slice()
+      .map(migrate)
+      .sort((a, b) => b.savedAt - a.savedAt)
+  } catch {
+    return []
+  }
+}
+
 export interface SaveOptions {
   id?: string
   name?: string
diff --git a/vite.config.ts b/vite.config.ts
index a52797c..94e2438 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -4,6 +4,10 @@ import { fileURLToPath, URL } from 'node:url'
 
 export default defineConfig({
   plugins: [vue()],
+
+  server: {
+    port: 5200,
+  },  
   resolve: {
     alias: {
       '@': fileURLToPath(new URL('./src', import.meta.url)),