將程式碼加入書籤，可以唸出當前滑鼠選擇的文字。

書籤幫你唸.js

javascript: (() => {
  const synth = window.speechSynthesis;
  if (synth.speaking) {
    synth.cancel();
    return;
  }

  const selectedText = window.getSelection().toString();
  if (!selectedText) {
    return;
  }

  synth.speak(new SpeechSynthesisUtterance(selectedText)) 
})();

書籤幫你唸.min.js

(()=>{const e=window.speechSynthesis;if(e.speaking)return void e.cancel();const n=window.getSelection().toString();n&&e.speak(new SpeechSynthesisUtterance(n))})();

額外參考：

1. https://developer.mozilla.org/zh-CN/docs/Web/API/Web_Speech_API/Using_the_Web_Speech_API
2. https://mdn.github.io/web-speech-api/speak-easy-synthesis/