--- category: Components type: Navigation title: BackTop --- `BackTop` makes it easy to go back to the top of the page. ## When To Use - When the page content is very long. - When you need to go back to the top very frequently in order to view the contents. ## API > The distance to the bottom is set to `50px` by default, which is overridable. > If you decide to use custom styles, please note the size limit: no more than `40px * 40px`. Property | Description | Type | Default -----|-----|-----|------ visibilityHeight | the `BackTop` button will not show until the scroll height reaches this value | number | 400 onClick | a callback function, which can be executed when you click the button | Function | - target | specifies the scrollable area dom node | () => HTMLElement | () => window