# PDFViewer.activeTool

```ts
get activeTool(): ToolName | null
```

The active tool's name — `'selectText'` at rest by default, from the moment the viewer goes back to it — or `null` when no tool is active. A property, read like `viewer.scale`.

- Kind: getter
- Since: 1.0.0

Returns `ToolName | null`

```ts
const editing = viewer.activeTool === 'editText';
```

Part of [PDFViewer](https://kernstra.com/docs/web-sdk/api/pdfviewer) in the Kernstra Web SDK 1.0.0 API reference.

Web page: https://kernstra.com/docs/web-sdk/api/pdfviewer/activetool