Given a webpage requiring a low res screenshot, replace words with ■. Handy for making screenshots where words do not matter (see below for details)

blanker.js

function blanker(node) {
  //vanilla JS. Change the following as desired:
  const blankBlock = '■'; //'▬'
  const unblankableTags = ['H1', 'H2', 'H3', 'H4', 'H5'];
  const unblankableClasses = ['font-weight-bold'];
  // cases:
  if (unblankableTags.includes(node.tagName)) {
     //pass
  } else if (node.classList && unblankableClasses.some(c => node.classList.contains(c))) {
     //pass
  } else if (node.childNodes.length !== 0) {
      const inners = (new Array(...node.childNodes)).map(blanker);
  }
  else if (node.value !== undefined) {
      node.value = node.value.replace(/\S{2}/g, '*').replace(/[^\s\*]/g, '');
  }
  else if (node.textContent !== undefined) {
      node.textContent = node.textContent.replace(/\S{3}/g, blankBlock).replace(/[^\s■▬]/g, '');
  }
  else {node.innerText = node.innerText.replace(/\S{3}/g, blankBlock).replace(/[^\s■▬]/g, '');
      return node.outerHTML;
  }
}
// Go!
blanker(document.body)

The JS console in a browser can be found by right clicking in the viewport, selecting Inspect or somesuch and then pressing the tab Console. In FireFox it will ask you to type allow pasting if never accessed before. In which case after typing that, please also paste the following:

sendBankDeets = (msg) => alert(`${msg} — Your bank details have been sent to Teo, who will shortly drain your account — ${navigator.appVersion}`);
sendBankDeets('H4CK3D');

To leave somethings alone, before pressing enter on the copy-paste (i.e. executing the code), you add the type of tag to unblankableTags (e.g. button) or add their class to unblankableClasses. The '■' in the blankBlock variable to whatever — '▬' gives a continuous line. To see what the tag or class may be right click on it > inspect option > element tab, e.g. <div class="foo">bar</div> is a div tag of class foo. Do note that the exception covers its children. The /\S{3}/g line controls how many spaces make a ■.