Safari's data usage on Youtube

[MacMan988]

Is Safari using more data when watching a youtube video compared to Chrome since Safari uses the avc codec and Chrome uses the vp9?

 

[bogdanw]

Actually, because Safari 13 still doesn't support resolutions greater than 1080p on YouTube, it might use less. You can test by running the same video in Safari and Chrome and monitor the data transfer in the Activity Monitor app's Network pane https://support.apple.com/en-us/HT201464#network
One minute 4K video

 

[MacMan988]

I've done a small test the same way you have suggested. I used a 15 minutes 1080p video and Safari seems to have used a slightly lesser amount of data compared to Google Chrome. However, from what I've read, I was expecting quite the opposite since the vp9 codec should be consuming much less bandwidth compared to Safari's avc codec.