Why does the CDN not deliver a .webp suffix in the URL?

The creoline® CDN delivers static resources and their associated MIME types via the HTTP response headers. Web browsers do not interpret images on the basis of the URL suffix, but on the basis of the returned Content-Type header. This gives the impression that the CDN does not generate WebP graphics.

Why don't we customize the URL?

We deliberately deliver .webp graphics based on the old URL in order to offer maximum compatibility with devices that do not support WebP. Based on the visitor's HTTP request, we can identify whether the visitor supports the WebP format or not. Depending on support, we deliver the .webp variant, if activated in the settings.

How can I check whether images are delivered in WebP?

For technical analysis, you can navigate to the Access log in the Customer Center and check individual graphics for the type returned. The star symbol is displayed if an automatic conversion has taken place. In this case, the type image/jpg was converted to image/webp.

WebP compression saved 50% (6 KB) of the original file size.

creoline Customer Center - CDN Access Log](/api/attachments.redirect?id=fa06fde0-a634-46ef-b984-ee7539261c47)

As an alternative to the access log via our customer center, you can display the response headers of the respective URL directly. In Google Chrome, you can call up the corresponding URL and right-click on the graphic to select the menu item Examine. In the new window, select the NetworkAll tab. Then refresh the page so that the *.cstatic.io call can be logged.

creoline CDN Example Request - Google Chrome Dev Tools

Then select the HTTP request and navigate to the Header tab. The actual type (Content-Type) is now displayed in the "Response Header" area.

The following cstatic URL was used for the example:



server: creoline
cache-control: max-age=36000, public
content-length: 140660

// Actual MIME type / content type (here: WebP)
content-type: image/webp

date: Sat, 16 Jul 2022 12:17:07 GMT
etag: 8fc60884cf1d1f02956eb92cd991e48d
expires: Tue, 12 Jul 2022 01:53:35 GMT
last-modified: Wed, 08 Dec 2021 14:25:09 GMT
link: <https://shopware.creoline-demo.com/thumbnail/a8/56/1c/1638973501/hq_1280x1280_1920x1920.jpg>; rel="canonical"

// Information about the live conversion
x-converted: image/jpeg to image/webp
x-original-content-type: image/jpeg
x-original-content-length: 167952
x-quality: 80

// Information on the edge location
x-edge-pop: FRANKFURT

Detailed information on analyzing all response headers can also be found in the article Analyzing CDN response headers.