Sergei Kuleshov Sergei Kuleshov - 6 months ago 41
CSS Question

ASP.NET MVC 5, Less is very slow in debug mode

So, in our project we are using to process LESS files. The problem is that in debug mode (on developer machines) it works soooo sloooow. I understand, that for production is doesn't matter, but it makes life of developers much harder. Some details:

In web.config we have the following line:

<add name="LessAssetHandler" path="*.less" verb="GET" type="BundleTransformer.Less.HttpHandlers.LessAssetHandler, BundleTransformer.Less" resourceType="File" preCondition="" />

Bundles are rendered using


So when I look at page in Chrome Dev Tools, I see the following picture:

enter image description here

As you can see, it takes more than 3 seconds just to receive 304 back..
Weird problem is that: if right click on a line in network tab and open it in the new tab, it works super fast (49ms).

Does anybody know, how to speed it up? And could anybody tell if it's a problem in bundler, or it's by design, or something else?



So, the answer is this:

in web.config this thing has setting, which enables/disables cache. Just turning cache on solved the issue.


<assetHandler disableServerCache="true" disableClientCache="false" />


<assetHandler disableServerCache="false" disableClientCache="false" />