How to launch WhatsApp in flutter web or launch WhatsApp from browser?

You can give an anchor with href to https://api.whatsapp.com/send/?phone=(phone_number)

For full code

<a href="https://api.whatsapp.com/send/?phone=6281144441111&text=Hello">Send Hi to me</a>

Note:
Make sure you give your country code without (+).
for example 6281144441111

You need the url_launcher https://pub.dev/packages/url_launcher. Import the package in you're yaml and then in your .dart

Then use the launch function with the WhatsApp URL: launch('whatsapp://send?phone=$phonenumber')

For the launching the WhatsApp Website use launch('https://web.whatsapp.com')