Random blank images

  • Resolved paratame

    (@paratame)


    7 years, 5 months ago

    Hello there and thank you for this great plugin. Looks very promising and helps speed up a website a lot without messing with existing configuration which is so cool!
    I bought an API key from ewww and everything start to work immediately.

    I have checked my website from various browsers and configurations and everything looks crispy and super fast.

    I encounter the following problem. There is times where the images does not load and I get random blank images. Saving those images local and open it says it’s a webp file with wrong extension.
    I would like to ask if you encounter similar problems and why it’s happening in some images an not all, it’s harder to identify whats wrong.

Viewing 5 replies - 1 through 5 (of 5 total)
  • Thread Starter paratame

    (@paratame)

    7 years, 5 months ago

    From more research I have done seems to be something with cloudflare cache or SSL (Crypto) settings. I will give more info if I fix this and it’s a configuration thing.

    Thread Starter paratame

    (@paratame)

    7 years, 5 months ago

    This was the issue and that’s the workaround in a post at community of cloudflare.com

    Plugin Author rosell.dk

    (@roselldk)

    7 years, 5 months ago

    Hi,

    This plugin serves webp’s when jpegs are requested. It sets the Content-Type header to ‘image/webp’ to let the browser know that it is a webp. It does however not change the file extension. So that explains why you have trouble when saving images locally and opening.

    I haven’t looked into the cloudflare product.
    But I shall.

    But generally with CDN’s, you will have to tell it that the output varies with the “accept” header. Usually you configure the CDN to forward the “Accept” header.

    Btw: It just dawned to me today that WebP Express should set the Vary:Accept header not only when delivering a converted webp, but also when delivering a jpg. Otherwise, if the CDN requests a jpg while forwarding an Accept header that doesn’t contain ‘image/webp’, it will not get the ‘Vary:Accept’ response header.

    I am implementing that the Vary:Accept header also gets set when delivering jpgs in the next release. If you cannot wait, try inserting the following .htaccess rules above the WebP Express rules:

    <IfModule mod_headers.c>
  # Set Vary:Accept header for the image types handled by WebP Express.
  # The purpose is to make CDN cache both original images and converted images.
  SetEnvIf Request_URI "\.(jpe?g)" ADDVARY
  Header append "Vary" "Accept" env=ADDVARY
</IfModule>
    Thread Starter paratame

    (@paratame)

    7 years, 5 months ago

    Thanks for taking the time to look at this, my problem was on some iOS devices with safari and some windows machines with edge. The local test was made from a broken image I download from an edge browser and try to open the file.
    Any way the problem is fixed for now I am sure you will make the best adjustments in the future so the plugin will work for all (almost) 🙂

    My workaround is to add an exception so cloudflare will not cache jpgs which get corrupted some how after some time… wierd but was analyzed in 2 posts in their community

    • This reply was modified 7 years, 5 months ago by paratame.
    Plugin Author rosell.dk

    (@roselldk)

    7 years, 5 months ago

    I now looked into Cloudflare. I have created a new “I am on Cloudflare” section in the FAQ.

    See also this topic:
    https://ww.wp.xz.cn/support/topic/worked-on-staging-but-not-working-on-production/

    Also, I have fixed the .htaccess-rules in the new 0.9.0 release, so the Vary: Accept header is also send to browsers (and CDNs) that does not send “image/webp” in the “Accept”-header

Viewing 5 replies - 1 through 5 (of 5 total)

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