Request for Mozilla Position: Zstandard compression format for Content-Encoding

[nidhijaju]

Request for Mozilla Position on an Emerging Web Specification

• Specification Title: Zstd Content-Encoding
• Specification or proposal URL (if available): https://datatracker.ietf.org/doc/html/rfc8878
• Explainer URL (if available): https://docs.google.com/document/d/1aDyUw4mAzRdLyZyXpVgWvO-eLpc4ERz7I_7VDIPo9Hc/edit?usp=sharing
• Caniuse.com URL (optional):
• Bugzilla URL (optional): https://bugzilla.mozilla.org/show_bug.cgi?id=zstd
• Mozillians who can provide input (optional): @martinthomson

Other information

Zstandard, or "zstd", is a data compression mechanism, described in RFC8878, providing high compression ratios. The proposal is to add "zstd" to the tokens in the Accept-Encoding header, and decompress with Zstandard when the token is seen in the Content-Encoding header. It is anticipated to make pages load faster and reduce serving costs, by reducing CPU and/or bandwidth consumption, especially for dynamic content.

Chrome is currently evaluating implementing this, and is interested in other browsers' position on the specification.

[ricea]

I just found out that this was previously closed as defer: #105

I do not have a lot of new information to contribute, except that zstd adoption has continued to grow.

[rektide]

I noticed a couple items down is #771, which is for adding Compression Dictionary support to websites. This is WIP, but it seemingly could/would overcome a primary cause for the defer in #105 / here.

I'll comment in #105 as well.

[valenting]

I think we can close this as positive.

[martinthomson]

We can skip the dashboard for this one.

[ChlorideCull]

We can skip the dashboard for this one.

Are you sure? I just found out today through this issue that Mozilla has changed to positive instead of defer, because the dashboard still only shows #105 with the defer position when you search for "zstd" or "zstandard".

[jesup]

FYI, we just landed zstd support in Nightly

[saschanaz]

Indeed we have the dashboard item already which is not up to date.

standards-positions/activities.json

Lines 2025 to 2036 in 7166458

	{
	"ciuName": null,
	"description": "Zstandard, or \"zstd\" (pronounced \"zee standard\"), is a data compression mechanism. This document describes the mechanism and registers a media type and content encoding to be used when transporting zstd-compressed content via Multipurpose Internet Mail Extensions (MIME). Despite use of the word \"standard\" as part of its name, readers are advised that this document is not an Internet Standards Track specification; it is being published for informational purposes only.",
	"id": "zstd",
	"mozBugUrl": "https://bugzilla.mozilla.org/show_bug.cgi?id=1301878",
	"mozPosition": "defer",
	"mozPositionDetail": "While we believe zstd is a promising technology, its use in a general-purpose web browser (given the existing slate of compression algorithms) has not been demonstrated to provide compelling new utility, and does not clearly warrant the additional maintenance cost and attack surface of adding such code. We are deferring a final position pending a more comprehensive and quantitative analysis of the benefits zstd would unlock on the web today - either dictionary-less, with static dictionaries, or with dynamic dictionaries. For either of the latter two options, we'd also need a credible plan for generating and delivering those dictionaries that aligns with our values.",
	"mozPositionIssue": 105,
	"org": "IETF",
	"title": "Zstandard Compression and the application/zstd Media Type",
	"url": "https://datatracker.ietf.org/doc/html/rfc8478"
	},

[martinthomson]

A timely reminder that we probably want to update the dashboard. Note that this and that are subtly different things, so we might need to tweak a few things.