Simple Gain / Boost Volume on any website (Youtube, Vimeo, Twitch etc) video by only one click of bookmark button. Copy code below, then create new bookmark, and fill code below to location address.

gain

javascript:var g_6z; function cI_6z(){ var ctx_6z = new AudioContext(); var el_6z = document.querySelector("video") ? document.querySelector("video") : document.querySelector("audio")? document.querySelector("audio"):alert('Media DOM not exist. Aborting.'); if (el_6z){ g_6z = ctx_6z.createGain(); g_6z.gain.value = 1; var src_6z = ctx_6z.createMediaElementSource(el_6z); src_6z.connect(g_6z).connect(ctx_6z.destination); var p = document.createElement("div"); p.innerHTML = `<div class=vpc_6z id=vpc_6z><style>.vpc_6z{float:right;width:25%;position:fixed;bottom:0;padding:20px 20px;z-index:9999999;background:#444;color:#fff}.vpc_6z-hide{position:fixed;background:#444;padding:0;width:80px;height:30px;bottom:0;z-index:999999}.vpi_6z-hide{display:none}</style><button%20onclick='d=document.getElementById("vpi_6z"),"vpi_6z"==d.getAttribute("class")?d.setAttribute("class","vpi_6z-hide"):d.setAttribute("class","vpi_6z"),c=document.getElementById("vpc_6z"),"vpc_6z"==c.getAttribute("class")?c.setAttribute("class","vpc_6z-hide"):c.setAttribute("class","vpc_6z")'style=float:right;cursor:pointer;width:80px;height:30px>Toggle%20VP</button><div%20class=vpi_6z%20id=vpi_6z><button%20onclick='document.getElementById("vpc_6z").remove()'>Destroy%20Panel</button><h1>Volume%20Gain:%20<span%20id=volumeControl_e></span></h1><input%20max=100%20min=1%20onchange='v=this.value,cG_6z(v),document.getElementById("volumeControl_e").innerHTML=1*v+100,console.log(v)'style=width:100%%20type=range%20value=1></div></div>`;%20document.body.appendChild(p);%20}%20};%20function%20cG_6z(v){%20g_6z.gain.value%20=%20v;%20};%20cI_6z(1);

It didn't work . there are some strange chars. use this