Background Video Playback Fix / Prevent Video Pause on Tab Switch / 网页后台防暂停脚本

让网页视频/音频在切换标签页、窗口失焦、页面隐藏或冻结后继续播放，防止自动暂停。
Force video and audio to keep playing in the background. Prevent websites from pausing media during tab switching, window blur, page hiding, or freezing.

Install Now / 立即安装

安装后刷新目标网站即可生效。
After installing, refresh the target website.

中文说明

这是一个通用 Tampermonkey / Violentmonkey 油猴脚本，用来尽量阻止网页在切换标签页、窗口失焦、页面隐藏或页面进入冻结状态时强制暂停正在播放的视频和音频。

为什么会暂停

很多网站不是因为浏览器限制而暂停播放，而是在自己的播放器脚本里监听这些事件：

• blur
• visibilitychange
• pagehide
• freeze

当这些事件触发时，网站会主动调用 video.pause() 或 audio.pause()。这个脚本会在 document-start 尽早注入，观察这些后台事件但不阻断页面自己的事件监听器；在媒体正在播放或刚刚播放过时，它会把 document.hidden、document.visibilityState 和 document.hasFocus() 临时伪装成前台状态，同时只阻止由后台事件触发的 pause() 调用。

安装

1. 安装 Tampermonkey 或 Violentmonkey。
2. 点击上方醒目的 立即安装 / Install Now 按钮，或打开 background-video-playback-fix.user.js。
3. 在脚本管理器里确认安装。
4. 刷新需要后台播放的网站。

适用范围

脚本默认匹配全部 http://*/* 和 https://*/* 页面，也会尽量覆盖 iframe 中的播放器。它适合处理通过页面失焦、标签页隐藏、页面隐藏等事件主动暂停媒体的网站。

直播弹幕兼容

从 0.2.1 起，脚本不再包裹或吞掉 visibilitychange、blur 等页面事件。斗鱼、B 站直播等网站的弹幕、直播聊天、播放器 UI 仍然可以收到这些事件；脚本只会在这些事件之后拦截媒体自己的 pause() 调用。

用户主动暂停兼容

从 0.2.2 起，脚本会识别近期真实的鼠标、触摸和播放器快捷键操作。即使网站在拖动进度条或操作播放器时触发了 blur，用户随后主动点击暂停仍会被放行；没有用户操作的后台自动暂停仍会被阻止。

限制

这个脚本不能绕过 DRM、付费权限、浏览器自动播放策略、网络限制或网站服务端限制。如果某个网站必须依赖真实的页面可见性状态完成业务逻辑，启用脚本后也可能影响该页面行为。

调试

在浏览器控制台输入：

window.__backgroundMediaPlaybackKeepalive

可以查看脚本是否安装、观察到多少后台事件、阻止了多少次后台自动暂停，以及放行了多少次用户主动暂停。

English Guide

Background Video Playback Fix is a general Tampermonkey / Violentmonkey userscript that keeps video and audio playing when websites try to pause media after tab switching, window blur, page visibility changes, pagehide, or page freeze events.

Root Cause

Many sites do not pause because of a browser media policy. Their player code listens for background-related events such as:

• blur
• visibilitychange
• pagehide
• freeze

When those events fire, the site actively calls video.pause() or audio.pause(). This script runs at document-start, observes those background events without blocking the page's own listeners, temporarily reports the page as visible while media is active or recently active, and blocks only the pause() calls that are triggered near those background events.

Install

1. Install Tampermonkey or Violentmonkey.
2. Click the prominent Install Now button above, or open background-video-playback-fix.user.js.
3. Confirm the installation in your userscript manager.
4. Refresh the site where you want background playback.

Scope

The script matches all http://*/* and https://*/* pages and also tries to cover player iframes. It is intended for sites that pause media through blur, tab-hidden, page-hidden, or freeze handlers.

Live Danmaku Compatibility

Since 0.2.1, the script no longer wraps or swallows visibilitychange, blur, or related page events. Danmaku overlays, live chat, and player UI on live sites such as Douyu and Bilibili Live can still receive those events; the script only blocks media pause() calls that follow them.

Intentional Pause Compatibility

Since 0.2.2, the script recognizes recent trusted mouse, touch, and player-keyboard interactions. A user's pause request is allowed even if dragging the seek bar or operating player controls caused a blur; background pause calls without user interaction are still blocked.

Limits

This script does not bypass DRM, paid access, browser autoplay rules, network limits, or server-side restrictions. On sites that require real page visibility state for normal behavior, the script may change page behavior while media is active.

Debug

Run this in the browser console:

window.__backgroundMediaPlaybackKeepalive

It exposes install status, observed background events, blocked pause calls, and user-requested pauses that were allowed.