---
title: "Downloading"
description: "Fetch the full PDF bytes of an open document, with incremental or full-rewrite save modes."
source: "https://www.cloudpdf.com/docs/engine/core-concepts/downloading"
---

# Downloading

`doc.download()` returns the complete PDF as bytes — including any annotation or
metadata edits that have landed on the document.

```ts
download(opts?: { mode?: PdfSaveMode }): AbortablePromise<Uint8Array>;
```

## Downloading bytes

```ts
const bytes = await doc.download();

// Browser: trigger a save dialog
const blob = new Blob([bytes], { type: 'application/pdf' });
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
a.download = 'document.pdf';
a.click();
URL.revokeObjectURL(url);
```

```ts
// Node: write to disk
import { writeFile } from 'node:fs/promises';
await writeFile('document.pdf', await doc.download());
```

## Save modes

`mode` controls how the PDF is serialized:

| Mode                      | Behavior                                                                                                                            |
| ------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| `'incremental'` (default) | Appends changes as an incremental update, preserving the original bytes and the document's revision history. Faster; smaller diffs. |
| `'rewrite'`               | Rewrites the whole file from scratch. Produces a clean, compact PDF without the incremental-update trail.                           |

```ts
const compact = await doc.download({ mode: 'rewrite' });
```

> `'incremental'` is the default because it's cheaper and keeps the
> original file intact. Reach for `'rewrite'` when you want the
> smallest possible output or a file without prior revisions.

## Cancellation and errors

Like every engine call, `download()` is an `AbortablePromise` and rejects with a
typed `EngineError`:

```ts
const pending = doc.download({ mode: 'rewrite' });
// pending.abort() to cancel

try {
  const bytes = await pending;
} catch (err) {
  if (EngineError.is(err, EngineErrorCode.Forbidden)) {
    // caller's scope doesn't permit download
  }
}
```

> Downloading the original bytes is gated by the caller's scope on the cloud. If
> the token doesn't grant it, `download()` rejects with
> `Forbidden` — check `doc.security.effectiveScope` before
> showing a download button.