Title: milcomp's Replies | WordPress.org --- # milcomp [ ](https://wordpress.org/support/users/milcomp/) * [Profile](https://wordpress.org/support/users/milcomp/) * [Topics Started](https://wordpress.org/support/users/milcomp/topics/) * [Replies Created](https://wordpress.org/support/users/milcomp/replies/) * [Reviews Written](https://wordpress.org/support/users/milcomp/reviews/) * [Topics Replied To](https://wordpress.org/support/users/milcomp/replied-to/) * [Engagements](https://wordpress.org/support/users/milcomp/engagements/) * [Favorites](https://wordpress.org/support/users/milcomp/favorites/) Search replies: ## Forum Replies Created Viewing 5 replies - 1 through 5 (of 5 total) * Forum: [Plugins](https://wordpress.org/support/forum/plugins-and-hacks/) In reply to: [[Converter for Media - Optimize images | Convert WebP & AVIF] Using Cloudflare PRO with this plugin](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/) * Thread Starter [milcomp](https://wordpress.org/support/users/milcomp/) * (@milcomp) * [5 months ago](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/#post-18726854) * [@mateuszgbiorczyk](https://wordpress.org/support/users/mateuszgbiorczyk/) Did you test it with an added Cookie header as well? 🙂 Try it, it won’t be a Cache HIT. * Forum: [Plugins](https://wordpress.org/support/forum/plugins-and-hacks/) In reply to: [[Converter for Media - Optimize images | Convert WebP & AVIF] Using Cloudflare PRO with this plugin](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/) * Thread Starter [milcomp](https://wordpress.org/support/users/milcomp/) * (@milcomp) * [5 months ago](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/#post-18726846) * [@mateuszgbiorczyk](https://wordpress.org/support/users/mateuszgbiorczyk/) Yes, I understand that from the plugin’s perspective everything is configured correctly. However, the issue is that in practice, it doesn’t work on real production sites. * The problem is that Cloudflare PRO plan does not cache resources with Vary: Accept header when cookies are present in the request – and practically every visitor has tracking cookies (Google Analytics, Facebook Pixel, marketing tools, etc.). * So while your plugin correctly configures everything and removes Cache-Control: private, Cloudflare itself bypasses the cache due to the combination of cookies + Vary header. This means: - âś… Works in testing (curl without cookies) → HIT - ❌ Fails in production (real users with cookies) → BYPASS - ❌ No CDN benefit, all traffic hits origin server If your plugin’s concept relies on Cloudflare’s “Vary for Images” feature, you should be aware: It will not work on most real-world sites where visitors have tracking cookies– which is basically every site using analytics. * This appears to be a Cloudflare PRO plan limitation, not a plugin issue. But it makes the nginx routing approach incompatible with real production CDN usage. * Perhaps the documentation should mention this limitation, or consider an alternative approach that doesn’t rely on Vary: Accept for sites on Cloudflare PRO plans? * Cheers! Marton * Forum: [Plugins](https://wordpress.org/support/forum/plugins-and-hacks/) In reply to: [[Converter for Media - Optimize images | Convert WebP & AVIF] Using Cloudflare PRO with this plugin](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/) * Thread Starter [milcomp](https://wordpress.org/support/users/milcomp/) * (@milcomp) * [5 months ago](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/#post-18726796) * [@mateuszgbiorczyk](https://wordpress.org/support/users/mateuszgbiorczyk/) I discovered the root cause of the BYPASS issue. It’s related to cookies in the request. * Test Results: * When I test with curl without cookies, I get a HIT: curl -I “[https://vates.hu/wp-content/uploads/2025/11/image.jpg”](https://vates.hu/wp-content/uploads/2025/11/image.jpg”);\- H “Accept: image/webp”Result: CF-Cache-Status: HIT âś… * However, when I include cookies (like the ones set by WordPress analytics plugins such as Sourcebuster.js – sbjs_* cookies, or Facebook Pixel _fbp cookies), I get BYPASS: curl -I “[https://vates.hu/wp-content/uploads/2025/11/image.jpg”](https://vates.hu/wp-content/uploads/2025/11/image.jpg”);\- H “Accept: image/webp” \-H “Cookie: sbjs_migrations=…; _fbp=…”Result: CF-Cache- Status: BYPASS ❌ * The Problem: * In real-world production environments, almost all visitors have cookies set by analytics/marketing plugins (Google Analytics, Facebook Pixel, etc.). This means images are never cached by Cloudflare CDN – defeating the entire purpose of using a CDN. * According to [https://developers.cloudflare.com/cache/advanced-configuration/vary-for-images/](https://developers.cloudflare.com/cache/advanced-configuration/vary-for-images/), the “Vary for Images” feature should work with PRO plans. However, it appears that when the Vary: Accept header is combined with cookies in the request, Cloudflare bypasses the cache. * I’ve already tried: - âś… Cloudflare Variants API is configured correctly (shown in my previous message) - âś… Removed Cache-Control: private from nginx config - âś… Created Cache Rules in Cloudflare to force caching for /wp-content/uploads/* - âś… Purged Cloudflare cache multiple times - ❌ Still getting BYPASS when cookies are present * _Question: Is this a known limitation of the Cloudflare PRO plan with the Vary: Accept header? Does this plugin only work properly with Cloudflare Business/Enterprise plans, or am I missing something in the configuration?_ * Any guidance would be greatly appreciated! * Best, Marton * Forum: [Plugins](https://wordpress.org/support/forum/plugins-and-hacks/) In reply to: [[Converter for Media - Optimize images | Convert WebP & AVIF] Using Cloudflare PRO with this plugin](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/) * Thread Starter [milcomp](https://wordpress.org/support/users/milcomp/) * (@milcomp) * [5 months ago](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/#post-18726707) * What I really don’t understand, that in CF the Vary is successfully configured by the plugin: * ```wp-block-code curl "https://api.cloudflare.com/client/v4/zones/3df2cfb4672039e0df74d3b33b98ab30/cache/variants" \ --header "Authorization: Bearer ***" { "result": { "editable": true, "id": "variants", "modified_on": "2025-11-20T13:09:13.770148Z", "value": { "gif": [ "image/gif", "image/webp", "image/avif" ], "jpeg": [ "image/jpeg", "image/webp", "image/avif" ], "jpg": [ "image/jpeg", "image/webp", "image/avif" ], "png": [ "image/png", "image/webp", "image/avif" ], "webp": [ "image/webp", "image/avif" ] } }, "success": true, "errors": [], "messages": [] } ``` * However, still no HIT :’) * Forum: [Plugins](https://wordpress.org/support/forum/plugins-and-hacks/) In reply to: [[Converter for Media - Optimize images | Convert WebP & AVIF] Using Cloudflare PRO with this plugin](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/) * Thread Starter [milcomp](https://wordpress.org/support/users/milcomp/) * (@milcomp) * [5 months ago](https://wordpress.org/support/topic/using-cloudflare-pro-with-this-plugin/#post-18726686) * Thanks for the quick Reply! I sent you on Slack and to the [hello@mattplugins.com](https://wordpress.org/support/users/milcomp/replies/hello@mattplugins.com?output_format=md) address as well. Sorry, wouldn’t share the hosting details here, I hope you understand. Thank you! Viewing 5 replies - 1 through 5 (of 5 total)