jpeg_to_progressive does not work

[John Mase]

basically progressive jpeg doesnt work on my site and i dont know why. i tried on webpagetesst and result showed 0/100 while they are all jpg
i have this on nginx config
pagespeed EnableFilters convert_jpeg_to_progressive;

[John Mase]

im using invisionpowerboard

<span style="background-image:url(http://forum/screenshots/thumb-27181680c0d52d025ee3095b3e10a478-cover.jpg.pagespeed.ce.QlXNYwRtpT.jpg)" class="ipsThumb ipsThumb_medium ipsThumb_bg ipsCursor_pointer" data-ipslightbox="" data-ipslightbox-group="download_62130" data-fullurl="me/forum/screenshots/27181680c0d52d025ee3095b3e10a478-cover.jpg">

<img src="me/forum/screenshots/thumb-27181680c0d52d025ee3095b3e10a478-cover.jpg.pagespeed.ce.QlXNYwRtpT.jpg" alt="" itemprop="image">

</span>

[Jan-Willem Maessen]

Hi John -

Do you have a pointer to the site (and if you still have them, your webpagetest results)?  The html snippet you linked doesn't give a feel for how large the files are.  In particular, we do *not* convert smaller jpeg files to progressive, because that actually makes them larger.  Only large jpegs benefit from this optimization.

-Jan 

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[John Mase]

http://www.webpagetest.org/result/150725_Y2_65H/1/performance_optimization/#first_byte_time

Den lördag 25 juli 2015 kl. 07:22:58 UTC+2 skrev John Mase:

[Jan-Willem Maessen]

Ah – it looks like most of your images are being served from a CDN, and it looks like those are simply not being optimized.  If it's a pull CDN (getting data from your service and caching it), you should simply be able to authorize the domain for rewriting.  See the domain docs for more details:

https://developers.google.com/speed/pagespeed/module/domains

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[John Mase]

thanks that works. When i did the pagetest i had cdn turned off for images. But i added the filter you mention and works great thanks yet again

Den lördag 25 juli 2015 kl. 07:22:58 UTC+2 skrev John Mase: