Cf-polished header always returning status=vary_header_present

I see my cf-polished header is always returning status=vary_header_present

Sample url: https://www.randymajors.org/map-tools (view any of the image files such as countygmap.png in the Network Panel)

I see my vary headers are Origin and Accept-Encoding

Any idea what is causing polish not to work, and how to fix please?

The whole cf-polished header is:

cf-polished: origSize=887402, status=vary_header_present

That means that polish could reduce the size of the image from 887.402kb to the current size (675kb). As the Image is not served in WEBP Cloudflare was not able to convert the PNG to a file which is smaller then the optimized PNG file.

Now if you ask yourself, WHY was it not able to produce a smaller file with WEBP?
It is because of your configuration:
image

This indicates you have set WEBP settings to “Lossless”. I personally would recommend setting it to “Lossy” the quality change will be bearly noticeable.

About that:

What is wrong with this? And why do you think this forces Polisch not to work?

1 Like

Thank you for the help on this! I hadn’t understood the nuance between Lossless and Lossy as it relates to pngs. (e.g. the “Serve WebP images” option only works on png when Lossless is used, not Lossy…as I just re-read in the Help drop down under the Polish setting)

As for vary_header_present, I guess I misunderstood that too when it stated " vary_header_present: The origin web server has sent a Vary header with a value other than accept-encoding ."
I guess I interpreted that as an error message, but I see that it is not (reading from Using Cloudflare Polish to compress images – Cloudflare Help Center )

Thank you again for your help!

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