---
title: Document.onoffline
slug: Web/API/Document/onoffline
translation_of: Web/API/Document/onoffline
---
<p>{{APIRef("DOM")}}</p>

<p>在<a href="/en-US/docs/Web/API/NavigatorOnLine.onLine">navigator.onLine</a> 属性更改并变为 <code>false时，</code>在 body或冒泡到body上的{{event("offline")}}事件被触发。</p>