Stop Visual Studio from launching a new browser window when starting debug?

Open your startup project's properties (Project → {ProjectName} Properties... from the main menu or right click your project in the Solution Explorer and choose Properties), then navigate to the Web tab and under Start Action choose Don't open a page. Wait for a request from an external application.

You will still be able to use any browser (or Fiddler, whatever) to access the running application, but it won't open the browser window automatically, it'll just start in the background and wait for any requests.

For VS 15.7.1 Tools → Options → Projects and Solutions → Web Projects → uncheck Stop debugger when browser window is closed.

In Visual Studio 2019, I resolved the same issue as below:

Go to your Visual Studio options Tools >>> Options >>> Project and Solutions >>> Web Projects then finally untick option >>> Stop debugger browser window is closed, close browser when debugging stops

Step 1:

Step 2: untick option >>> Stop debugger browser window is closed, close browser when debugging stops

Step 3:

Then finally click on >>> OK button, these are all the steps to resolve the issue.

I have solved my problem by following below steps. Go to Tools >> Click on options >> click on projects and solutions >> web projects >> uncheck "Stop debugging when browser is closed" option

This workaround works for me for VS 2019

Tools => Options

Then type Projects and solutions in the search box.

Select the Web Projects.

Then deselect the option below.

Stop debugger when browser window is closed, close browser when debugging stops.

This works for me. Hope this will help.

As I did not had the mentioned option in my VS which is Visual Studio Enterprise 2017, I had to look for some other option.

Here is it what I've found:

Go to Tools -> Options -> Debugging tab(General) and uncheck "Enable JavaScript debugging for Asp.Net(Chrome and IE).

You can use the Attach To Process function, rather than pressing F5.

This can also allow you to navigate through known working sections without the slowdown of VS debugger loaded underneath.

When you first open a web/app project, do a Ctrl-F5, which is the shortcut for starting the application without debugging. Then when you subsequently hit F5 and launch the debugger, it will use that instance of IE. Then stop and start the debugging in Visual Studio instead of closing IE.

It works on my machines. I'm using the built in dev web server. Don't know if that makes a difference.

Firefox will also stay open so you can debug in either or both at the same time.

Here's what did it for me:

Go to Project Properties > Debug > Uncheck "Launch Browser" > Save.

Joao Costa answer also holds true for .Net core 2 projects.

launchsettings.json --> "launchBrowser": false

"profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": false,
      "environmentVariables": {
        "Hosting:Environment": "Development"
      }
    }
}

You can right click on your project, then choose Properties , on Debug tab you should uncheck launch browser checkbox.

You can now also get to the Web properties by clicking the dropdown arrow next to the Run button!

1. Click dropdown button next to "Run"
2. { Project name } Properties
3. Click "Web" in the list on the left
4. Under the "Start Action" segment, click Don't open a page.

You're all set!

PS: This works for me, I'm on version 16.5.5 of VS Professional 2019 :)

If you're using the Web Publish feature in IIS, then the solution I found was to edit the publish configuration and remove the Destination URL from the configuration (leave it blank).

If this is defined, then every time you publish the project it will open the URL specified in the Destination URL (which is a redirect URL).

Reference: https://support.winhost.com/kb/a1604/visual-studio-publish-web-deploy.aspx