"$ flutter build web" is throwing the error "Missing index.html"?

It would help to see the output of your flutter doctor, but I am guessing that your project is not configured for web.

If you haven't already, you need to switch to the flutter beta channel like so:

$ flutter channel beta$ flutter upgrade$ flutter config --enable-web

At this point, running flutter doctor should show that chrome is available.

Then, switch into your application root directory, and run

$ flutter create .

This will rebuild the project to support web.

Then, from the same directory, you can run flutter build web

I had this problem. I could run web app in debug mode but I couldn't create web app.

Run this line in terminal to solve problem:

 flutter create .

This will add web app to your project.

It happens if you have already created flutter project before you switched to flutter channel beta.

By using flutter channel beta to create a new flutter project, you will have a web folder.

You can see on the above image, the Left one, Flutter_Web, was created using stable channel.

On the other side, Web2 was just created by using the beta channel.

So for your case, I suggest following steps :

• switch to Flutter Beta Channel here for details

• create new Flutter project using :

flutter create

• try to run

flutter run -d chrome

• replace your previous project lib folder to this new web project