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![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(278.4, 57.00000000000001%, 36%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ELM%3C/text%3E%3C/svg%3E)
I created a new Blazor Web Assembly app from visual studio 2022, and I got the usual template application with a counter button
When I run this app from my development machine, the first load take 20 seconds. Every time I change something in the code and re-run the application it takes 20 seconds to load.
Is this the normal behaviour or do I have something wrong on my development machine?
It's very hard to develop something if you have to wait 20 seconds everytime you want to test a modification
Looking at the network tab of the browser I see this:
As you can see 21.76 MB of resource are cached, and only 0.04 MB are downloaded from the network. So why does it take so long?
Do you have the same times while coding?
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(233.6, 98%, 32%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ERN%3C/text%3E%3C/svg%3E)
Hi @Ludovico M ,
Is this the normal behaviour or do I have something wrong on my development machine?
It seems not to be a normal behavior. Do you run this app on local or remote? Do you try to change another network to run your application?
I run it on my local machine, on the second screen (top left) you can see that I am on localhost. What do you mean with change to another network?
Hi @@Ludovico M , I mean maybe PC local Network will also influence download speed. Did you use any third-party plugin in your local machine? Try to close them and rerun your app. If above all suggestions still do not work. I am guessing your Visual Studio may have some issue, I suggest you redirect to Developer Community and report the problem, the expert will help you.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(278.4, 90%, 36%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ESZ%3C/text%3E%3C/svg%3E)
I had the same issue after upgrading from .NET Core 6 to 7. The page refresh went from 3" to 12". So for now i ll just stick with .NET Core 6.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(211.20000000000002, 9%, 30%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ECF%3C/text%3E%3C/svg%3E)
I also have this very slow loading time. My project is on .NET 7.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(211.20000000000002, 61%, 30%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EBS%3C/text%3E%3C/svg%3E)
why aren't you using hot load?
when you run the app a lot happens
1) code compiled
2) server site loaded into iis (express)
3) debugger attaches to server code
4) browser start with site url
5) blazor client code started
6) blazor client code loads debugging tools and WASM
7) debugger attaches to browser
your performance will depend on your machine. on my box (windows VM on a IMac Pro) it takes 12 seconds.
I use hot reload but, half of the time, it still needs a rebuild of the application that take the usual 20 seconds
Note that I'm not talking about debugging an application, even if I launch it without debug it still takes 20 seconds everytime. The problem is surely not my pc (a brand new I7 11th gen with 32Gb of ram), also the 12 seconds that you got are very high in my opinion.
I'm used to asp.net that is instantaneous to launch, but I find it hard to believe that blazor wasm is like that
Blazor is a complex configuration.
note: it should be faster if you run the app rather than use iis express.
on my 4 year old Mac hosting a windows vm, the default blazor Wasm app with core hosting:
1) rebuild: 5 seconds
2) run without debug, no code changes: 2 seconds
3) run without debug blazor code change: 5 seconds
on my native M1 using vs 2022 for Mac:
1) rebuild: 1 second
2) run without debug, no code changes: 1 second
3) run without debug blazor code change: 2 seconds
note: for the runs, the time is until fully displayed in the browser.
Ok, your times seems pretty reasonable, so it should be something on my development machine.
I actually got:
1) rebuild: 1 second
2) second run without debug, no code changes: 1 second
3) any run without debug blazor code change: 21 seconds
I got the same times with chrome and firefox
Maybe is it because I'm using Visual studio 2022 community edition?
I will investigate further
Thank you
I
The community edition is as fast as the pro, just less features.
you cant try work with dotnet watch
I found the problem. For me it was the antivirus in use in my company, ESET.
Disabling the antivirus is not solving the issue, I had to completely remove it to come back to normal development times