Early hints not working

Hello everyone!

We have activated Early hints in the settings. Also, the CSS-file is served in the Link-Header.

If I understand the “Early hints” feature correctly, it should emit a 103-Response early on to download the css file faster.

After I have activated the feature and also enabled the dev-mode of the cache, I didnt see any 103-Response in my browsers Network-Tab. Also, the css file was not downloaded faster.

Does anyone know what I might be doing wrong? :slight_smile:

Kind regards,

You will likely not see it anyway, since a 103 will turn in a 200 very quickly.
Thats how the header looks on my end:

$ curl -X HEAD -I https://www.heldmayer.com
HTTP/2 103
link: </assets/poppins-400-normal.woff2>; as=font; crossorigin; rel=preload, </assets/montserrat-800-normal.woff2>; as=font; crossorigin; rel=preload, </assets/app.min.css>; as=style; rel=preload, </assets/patrickheldmayer_lossy.webp>; as=image; rel=preload

HTTP/2 200

Notice, first the 103 is getting fired, then immediately after the 200, which makes the status turn into a 200, which you then will see in your dev console.

To test if your site does support Early Hints, you can use my selfmade simple tool


Also keep in mind, that Cloudflare does not always trigger a 103, since it sometimes is faster if just a 200 is triggered right away. But for this have a read here: Early Hints | Need More Data Before Switching Over - #22


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