Facebook.com serves lower-res assets to Fennec and B2G than Chrome Mobile

Assigned to


Tech Evangelism
2 years ago
9 months ago


(Reporter: miketaylr, Assigned: karlcow)


Firefox Tracking Flags

(Not tracked)


(Whiteboard: [country-all][sitewait])


(1 attachment)

As mentioned in Bug 1216185, but also reported by email.

For whatever reason, they're just sending us smaller assets.

Here are details from the email that was sent to me:


If you take a look at e.g. https://m.facebook.com/Firefox and take a 
look at the preview thumbnails for the photos section, you'll see that 
in the screenshot made in Chrome, the pictures look slightly sharper.

Taking the Firefox logo as an example, the reason for that seems to be 
this: Chrome receives this picture:

while Firefox is sent this picture:

Both pictures are scaled down to 120x120 px on display, however 
Firefox's picture is only 128x128x px large to begin with, while 
Chrome's picture is 180x180 px. Because Facebook tends to compress their 
images to the limit (or even slightly beyond that :-)), the larger image 
scaled down by the browser looks a bit better than the smaller image 
scaled down by Facebook. (And of course, those 120 CSS/layout(?)-pixels 
end up as 180 screen pixels on my device anyway).

When clicking on the photo 
I get a similar story:
Chrome gets this 400x400 px image:

while Firefox only receives this 320x320px image:

In the end, both images are scaled to 320x320 px, so again the page 
tends to look slightly sharper in Chrome.

I've tested with my Samsung Galaxy S3 Mini (Android 4.1.2) with Firefox 
41.0.2 and Chrome 46.
Created attachment 8675856 [details]
facebook image quality ff vs chrome.png
Hallvord, based on the description it seems like this is purely a UA string related thing (also in Bug 1216185). Would you mind taking a quick look to verify before we reach out to FB?
Flags: needinfo?(hsteen)
Whiteboard: [country-all][needsdiagnosis]

Navigation menu graphics - Firefox:

I can confirm that Firefox gets the hi-res graphics just by spoofing as Chrome. (However, the stuff they serve Chrome has quite different CSS and doesn't look good in Firefox at all.. Some webkit styling here?)
Flags: needinfo?(hsteen)
Harald, can you follow up with Facebook?
Flags: needinfo?(hkirschner)
Whiteboard: [country-all][needsdiagnosis] → [country-all][contactready]

Comment 6

2 years ago
FXOS MP uses FB's hosted m.site for the FB application.  Is it possible FB is serving us lower res images to account for certain hardware limitations on our devices?  (Fb is Tarako enabled as well.)

Given the recent news about FXOS, we will unlikely be able to move the needle here by leveraging our Contacts at FB.
Flags: needinfo?(hkirschner) → needinfo?(miket)
That's one possible explanation. Even with FxOS news, we would still like FB to send Fennec users the same hires assets that Chrome Mobile gets.
Flags: needinfo?(miket)

Comment 8

2 years ago
Will this be fixed soon? 
I guess even with the FxOS news, a huge population has to suffer a sub-par experience on Fennec on a popular website. 
If they need to try things out maybe filter nightly fennec users for the test?

Comment 9

2 years ago
Contacted Facebook by email.
Assignee: nobody → kdubost
Whiteboard: [country-all][contactready] → [country-all][sitewait]

Comment 10

a year ago
Still not fixed. I sent a reminder.


a year ago
See Also: → bug 1232091
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