User experience: data charge impact of PPP on cellular networks

[Kevsy]

Data charges for prefetch content need to be very clearly highlighted, especially if the user has to navigate to Chrome settings to opt-out of prefetch. A user unaware of this may run out of carrier data allowance faster than expected, resulting in complaint calls to the carrier who will be unable to diagnose the problem.

[buettner]

Fortunately, fetching only the mainframe HTML and potentially render-blocking resources like JS and CSS provides a large performance gain without using much data. Also, note that prefetching has been around for a awhile. The earliest I could dig up was 2003. The proxy just makes prefetching more private.

We estimate a data use increase on the order of 1%, but we'll know from our upcoming experiment.

[Kevsy]

Thanks, 1% sounds manageable - any update from the experiment much appreciated.

I'm focused on mobile browsing, I think the 2003 link relates to fixed prefetch. As I recall, mobile browser support for link rel=prefetch first appeared around 10 years ago with the Android browser, and required the website author to add the prefetch tag. The Google PPP seems to be implementing prefetch without the website author's involvement, and without user opt-in, is that correct? If so, x% uplift in requests for a 65%+ market share browser on a shared-spectrum network makes me interested to know what 'x' will be :). Thanks again for your help!

[buettner]

We'll definitely keep everyone posted on what we learn from the experiment.

Note that the Google PPP does require the website author to add the prefetch tag. It relies on the new Speculation Rules API, but that's conceptually the same as the existing tag. The user control is also the same, and is controlled by the "Preload pages for faster browsing and searching" setting.

Thanks for your interest, and for taking the time to post an issue!

[Kevsy]

We'll definitely keep everyone posted on what we learn from the experiment.

Much appreciated :)

Note that the Google PPP does require the website author to add the prefetch tag. .

That's good and thanks for confirming. Certainly that makes a difference as we estimate increased load.

The user control is also the same, and is controlled by the "Preload pages for faster browsing and searching" setting.

Is that planned to be 'on' by default?

Thanks for your interest, and for taking the time to post an issue!

Cheers and thanks for your updates!

[buettner]

Is that planned to be 'on' by default?

Yes. That setting is on by default and will continue to be.

[buettner]

Our experiments showed less than a 1% increase in network bytes when this feature is enabled.

Closing this issue, but please re-open if you still have concerns.