[DougWebb]

If your output is compressed (which it should be if you're worried about response size) then omitting end tags has much less impact, I believe. All of the tags should get compressed well because they're repeated so often, and they should be much smaller overall than your non-repetitive content.

[TheRealPomax]

But note that on the scale of move as much data around as Google does, or even "the web as a whole", shaving even a few bytes off of every single gzip packet stream can still equate to significant network relief.

[DougWebb]

I suspect their advice is for their benefit, not other website devs. They can save a lot of space in their archive if everyone's pages were smaller. Nothing compared to better image compression though.

[dgacmu]

No - a few bytes on a web page are insignificant compared to the data volume of images and movies. This is all about getting pages to load faster on mobile.

[nevir]

If those extra bytes drop you from two packets to one, that's a _significant_ reduction in traffic

(which, IIRC, was the original rationale behind that style guide rule)