I'm probably much older than you and I don't mind, and in fact, I regularly watch vertical videos. They don't bother me.

But here is some sloppy code you could create a basic browser extension and shove in content.js:

  function hideVerticalVideos() {
    const videos = document.querySelectorAll('video');
    videos.forEach(video => {
      if (video.videoHeight > video.videoWidth) {
        video.style.display = 'none';
      }
    });
  }

  // Run hideVerticalVideos() when the page loads
  window.addEventListener('load', hideVerticalVideos);

  // Run when the DOM updates
  const observer = new MutationObserver(hideVerticalVideos);
  observer.observe(document.body, { childList: true, subtree: true });

I wish everything was so great in my life that this could be a concern.

I need a browser extension to block video autoplay because no browser setting seems to work consistently.

Safari in particular has never worked, but I've had bad luck with Chrome and Firefox as well.

On youtube you can block the section with shorts in them with ublock (rclick > block element), this was good enough for my use. I don't know about other sites.

Someone should use generative AI to convert portrait video into landscape by extending the sides (rather than cropping).

I dislike vertical video also. Last I checked, phones can rotate 90 degrees to play landscape video.

On a related note, is there a browser that can completely block auto-playing video with a setting that actually works?

I find it depressing that web developers seem willing to do anything to ignore user preferences, especially when intrusive advertising is involved.

I’m not wild about vertical videos either. But are you sure a technical solution is the best solution for this issue?

It would be very hard to get rid of portrait videos that were uploaded as landscape but padded with black bars.