1627407 - Support Save-Data: Request Header so users can save bandwidth

Status: NEW

(Core :: Networking: HTTP, enhancement, P3)

Description

[techieshark]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:74.0) Gecko/20100101 Firefox/74.0

Steps to reproduce:

Viewed this page and noticed that Firefox does not support the Save-Data request header feature:

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Save-Data

Actual results:

Saw that Firefox does not support the Save-Data request header.

Chrome and Opera do support it. A post[1] from Chrome says:

There are alternative methods for improving site speed without direct developer involvement, such as proxy browsers and transcoding services. Although such services are quite popular, they come with substantial drawbacks — simple (and sometimes unacceptable) image and text compression, inability to process secure (HTTPS) pages, only optimizing pages visited via a search result, and more. The very popularity of these services is itself an indicator that web developers are not properly addressing the high user demand for fast and light applications and pages.

1: https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/save-data

Expected results:

Expected Firefox (both on Desktop and mobile) to support the header - thus being a leader in terms of delivering an equitable Internet experience to the people of the world who may not all have access to cheap high speed internet.

This seems especially important in the current (April 2020) coronavirus context where many more people are being asked to use their own internet access from home to perform their work remotely.

Even post-virus, support for data-saving measures such as this could benefit the planet as a whole, since data centers have high environmental costs (estimates peg it as being worse than flying in terms of total carbon emissions), so lowering bandwidth for many users could lead to lower data center environmental costs.

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Specifically (technically), I would think a good easy first step might be to allow developers and tech-savvy users to turn on the flag for all sites by enabling an experimental feature flag in about:config.

Longer term, I'd hope there'd be a UI exposed to less tech-savvy users which allows them to toggle Save-Data on or off. For more ideas, see this webpage: https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/save-data#implementation_tips_and_best_practices

Comment 1

[Alin Ilea, Desktop Test Engineering]

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:74.0) Gecko/20100101 Firefox/74.0

Hi,

I will move this enhancement over to a component so developers can take a look over it. If this is not the correct component please feel free to change it to an appropriate one.

Thanks for the suggestion.

Comment 2

[Junior [inactive]]

P3 given it's a new client hint request header.