> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Global methods

> Global methods for encoding and decoding Base64 strings.

Global JavaScript methods available to Custom activity scripts for Base64 encoding and decoding.

## Methods

### btoa

```javascript theme={null}
string btoa(string input);
```

Encodes a string as Base64.

### atob

```javascript theme={null}
string atob(string base64Input);
```

Decodes a Base64 string back to its original form.

## Related topics

<CardGroup cols={3}>
  <Card title="BinaryFile" icon="file-binary" href="/vantage/documentation/skill-designer/process/custom-activity/binary-file">
    File data in binary format — typically the pre-preprocessing source image.
  </Card>

  <Card title="HttpRequest" icon="globe" href="/vantage/documentation/skill-designer/process/custom-activity/http-request">
    Send urlencoded, text, JSON, or binary HTTP requests from a script.
  </Card>

  <Card title="Object model" icon="diagram-project" href="/vantage/documentation/skill-designer/process/custom-activity/object-model">
    Full JavaScript object reference for Custom activity scripts.
  </Card>
</CardGroup>