To be able to turn a group into a message broadcast channel, first, open the app and tap on the menu button (in the top right corner of the screen):

WhatsApp’s home screenWhatsApp’s home screen

While the menu is open, tap on New Group:

WhatsApp’s menuWhatsApp’s menu

Now, select the participants in the group and tap on the green arrow icon:

Creating a groupCreating a group

Next, write a name for the group and tap on the green tick button:

Naming and creating the groupNaming and creating the group

Then, tap the menu button within the group again:

WhatsApp group createdWhatsApp group created

Now, tap on Group info:

Group conversation menuGroup conversation menu

On the next screen, tap on Group Settings:

Group informationGroup information

Now, tap on Send Messages:

Group settingsGroup settings

Finally, we change the option of All participants to Only admins:

Message publication settingsMessage publication settings

When you get back to the group's conversation, you will see a message informing you that from now on, only administrators will be able to post content:

Admin permissions changedAdmin permissions changed

These kinds of groups are especially useful when it comes to spreading information, for example, from a company to its workers or a community of neighbors. In fact, WhatsApp's main competitor's broadcast groups have been offering these features for a long time, and as usually happens with other Telegram or any other app features, WhatsApp's users demand them until they are implemented.

Although they are not as diverse in functionality as their direct rivals, WhatsApp's broadcast groups are still useful for sending short messages.