CDN is changing my images

I’m unsure why this is happening. I have a valid png file that is 844 bytes.

When proxy status is set to DNS only the png displays correctly on my site. But when I set proxy status to “DNS and HTTP Proxy (CDN)” any request for the same png file downloads 1436 bytes and is no longer a valid png.

I have compared a hexdump of both the 844 byte original (correct) version and the 1436 byte version served by Cloudflare and see all of the data in the original exists in the larger one, but there is some other data in there.

The same thing happens for all images, and I even renamed the png to .txt and the same thing happened. But php/html files work correctly.

I can’t understand what is going on, can anyone offer any insight or point me in the right direction?


Are you on a Pro plan and have Polish enabled?

Whats the URL?

I am on the Free plan, Polish is not available to me

Is there a private messaging system here? I prefer not to post my URL publicly

You can run a query at and post back here when you ran it, so I can check.

I have run the query and it says my site is up

Does your server IP address end in 83?

No, it is .3

Can you run a second check at with that IP address?


My guess would be some transfer encoding issue. Check if your server is handling that properly. Do you have Brotli enabled in your Cloudflare account?

If nothing works, open a support ticket and maybe they can figure out if there is an encoding issue or why else the file seems to get inflated by Cloudflare’s proxies.

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Thanks for your assistance. The server is serving the correct file size, which I gather from the access log and Brotli is disabled.

I’ll monitor it through the day in case it was an intermittent issue, if it doesn’t resolve itself by end of today I will open a support ticket

Double check that your transfer encoding is correct. It would seem so from the direct request, but something seems to be off in this regard and that could be in your configuration as well.

I’d open a ticket straight away however, based on the observed behaviour I wouldnt think it is just a temporary glitch.

I have other domains that are on the same server that are not exhibiting this behaviour. For this reason I don’t feel like it could be the webserver at fault. I have opened a support ticket now. Thanks again for your prompt responses.

Do they have the identical configuration? If not, there simply could be some issue with that domain’s configuration.

Anyhow, post the ticket number here too, so @cloonan can keep track.

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The config on both domains is the same, I have carefully inspected the vhosts and fpm configs

Ticket number is #1730587

Go it, thank you. Can you reply to the autoreply you received @kenny2? Let the engineer know the helpbot reply was not helpful and they’ll note that as well.

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