---
url: /process-functions/workbook-convertfrombase64.md
description: Returns a workbook that has been decoded from Base64
---

# workbook.convertFromBase64

Returns a workbook that has been decoded from Base64

```js
let wb = workbook.convertFromBase64(base64str, [password]);
```

#### Parameters

* `base64str` - Base64 data.
* `password` - Optional, The workbook password.