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

When I run:

$ flutter build web

I'm getting the error

Missing index.html.

The flutter app is displaying in the browser, but in VS Code it reads "No Device." How can I debug, or fix this problem?

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.


[![enter image description here][1]][1]


[1]:

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](

[To see links please register here]

)

- 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`

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 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 to create a `web/index.html` directory at the root of my application.
After running `flutter build web` the build folder was populated with the compiled web files.

Below is my Flutter config. I'm using a flutter version manager btw


```
mobile_web_sample % fvm flutter --version
Flutter 2.1.0-13.0.pre.439 • channel master •

[To see links please register here]

Framework • revision d226d43912 (7 hours ago) • 2021-04-03 02:54:02 -0400
Engine • revision a0b52ae6bf
Tools • Dart 2.13.0 (build 2.13.0-194.0.dev)
```

On the new project creation screen with android studio, you need to tick the web box with ios android in the devices option.

If you do not check this box, the web folder will not appear under the lib folder.

To add web support to an existing project created using a previous version of Flutter, run the following commands from your project’s top-level directory:

flutter create --platforms web .

flutter clean

flutter pub get

flutter build web

good luck