title: Lazy load images without changing existing `src` attribute (not changing the HTML)?
body: <p>Due to a constraint, we need to display HTML content from a different service which images are just typical <code>&lt;img src="http://example.com/image.jpg"/&gt;</code></p>
  
  <p>Most of lazy loading libraries (e.g <a href="https://apoorv.pro/lozad.js/" rel="nofollow noreferrer">lozad.js</a>) suggested removing <code>src</code> attribute and adding <code>data-src</code> otherwise browser will load each image immediately.</p>
  
  <p>I can parse and transform the dom to conform the requirement but I feel adding extra overhead is defeating the performance purpose.</p>
  
  <p>Is there any technique to achieve lazy loading without touching the HTML?</p>