1402250 - Evaluate whether we still need -moz-crisp-edges on favicons

Status: NEW

(Firefox :: Theme, enhancement, P3)

Description

[Marco Bonardo [:mak]]

This is splitted from bug 1401851, even if we're now storing and using more hi dpi favicons, we are not yet comfortable with jut removing crisp-edges.

We need to collect and analyze more data to understand if we're at a point where crisp-edges does more damage than benefit.

We could store some telemetry about the percentage of pages in favicons.sqlite that don't have an icon larger than 16px. This together with the existing LINK_ICON_SIZES_ATTR_DIMENSIONS telemetry could help us making a call.

Comment 1

[Marco Bonardo [:mak]]

Attachment: Bug 1402250 - Evaluate whether we still need -moz-crisp-edges on favicons

Review commit: https://reviewboard.mozilla.org/r/182578/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/182578/

Comment 2

[Marco Bonardo [:mak]]

I posted the current patch, just as a placeholder, not intending to land it until we have data and a decision.

Comment 3

[Ed Lee :Mardak]

(In reply to Justin Dolske [:Dolske] from bug 1401777 comment #31)
> That this -moz-crisp-edges gets applied to favicons that are *downscaled* is unintentional.
At least for the in-tab favicon, similar to the fix in bug 1401777, it should be relatively straightforward to just pass the width data to set a style / class conditionally doing the crisp or smooth scaling.

Comment 4

[Marco Bonardo [:mak]]

we don't always know the favicon size, since the "sizes" attribute is optional and often omitted.

Comment 5

[Dão Gottwald [:dao]]

Tagging this for the Search team to look into since we own bookmarks and history.

Comment 6

[Yazan Al Macki [:yazan]]

Telemetry data shows that for users on Nightly 132 between 04-Sep-2024 and 10-Sep-2024, 4.2% of icons served by the page-icon protocol were smaller than requested.

Comment 7

[Marco Bonardo [:mak]]

Yazan could you please post your updated measurements with Release?

Comment 8

[Yazan Al Macki [:yazan]]

I wrote a redash query which shows that ~6.1% of page-icon requests on Fx release (29/10/2024 - 28/01/2025) return icons smaller than requested, hence require upscaling. If we completely remove moz-crisp-edges, then around 6% of page-icon requests will result in blurry icons, which I think is a significant amount.

Comment 9

[Will]

Has anyone looked at how Chrome deals with this? I've never noticed blurry favicons in Chrome or jagged/over sharpened favicons either, but people definitely notice the jagged/over sharpened favicons in Firefox

Comment 11

[Marco Bonardo [:mak]]

Chrome is pixelizing icons smaller than requested, with a better rescaling though.
image-rendering: pixelated would probably do that, if Bug 1731134 would be fixed, though there's no eta on that.
Overall applying -moz-crisp-edges seems to just make things uglier, and if we cannot easily find examples on the Web where it's helping, it may not really be worth it.
I'll see around if I can find examples of blurry icons, if you find any please feel free to post them. I mean blurry, not pixelated.

Comment 12

[Will]

Attachment: firefoxfaviconcrispURL.png

I've seen others point out that Firefox doesn't seem to apply anything to the favicons in URL bar results, it looks great and I don't think there's been any complaints or issues with blurry favicons in Firefox's URL bar results, has there? Either way, there should be consistency here (the same favicon shouldn't look different in the tab compared to the URL results).