# Resumable uploads (/docs/guides/resumable-uploads)



<ComponentPreview name="resumable-upload" />

## Pause and resume [#pause-and-resume]

Pausing aborts the in-flight request. What happens on resume depends on the adapter:

| Adapter                                                     | Resumable | On resume                                    |
| ----------------------------------------------------------- | --------- | -------------------------------------------- |
| `s3Adapter` (multipart)                                     | ✓         | Continues from the last finished part        |
| `multipartAdapter`                                          | ✓         | Continues from the last finished part        |
| `tusAdapter`                                                | ✓         | Asks the server for the offset and continues |
| `s3Adapter` (single PUT), `presignedAdapter`, `httpAdapter` | ✗         | -                                            |

`UploadPause` only appears for resumable uploads (`uploader.canPause(item)`), so users
are never offered a pause that would silently restart. Queued items can always be paused.

## Surviving reloads [#surviving-reloads]

Pass a persistence store. Queued and in-progress uploads, **including the file bytes**,
are written to IndexedDB along with each adapter's resume state.

```tsx
const [persistence] = React.useState(() => createIndexedDBPersistence())
const uploader = useUploader({ adapter, persistence, restore: true })
```

After a reload, `restore` brings them back as `paused` with `pauseReason: "restored"`.
Call `uploader.resume()` (or let users press resume) to continue.

### Good to know [#good-to-know]

* **Storage quotas.** Browsers allow IndexedDB to use a large share of free disk space,
  but may evict it under pressure. Call `requestPersistentStorage()` to ask for durable
  storage.
* **Multiple tabs.** When Web Locks are available, each running upload holds a lock, and
  `restore()` skips uploads another tab is already running.
* **Expiry.** Records older than 7 days are dropped (`maxAge`).
* **Server state.** Incomplete S3 multipart uploads are billed until aborted. Add a
  bucket lifecycle rule to clean up abandoned ones.

## Persistence for other stores [#persistence-for-other-stores]

Implement the three-method interface to persist elsewhere:

```ts
interface UploadPersistence {
  load(): Promise<PersistedUpload[]>
  save(record: PersistedUpload): Promise<void>
  remove(id: string): Promise<void>
}
```