CNBC Explains

Breaking down three popular messaging services

Remember having to pay extra for international texts every time you traveled abroad, or the hassle of entering a slew of contacts whenever you changed devices?

The options have multiplied—all for free or very little money. With a smartphone and Internet connection, you don't need an SMS plan to stay in touch.

CNBC breaks down the basics of three popular mobile messaging services: WhatsApp, Line and WeChat.

WhatsApp displayed on a Samsung Galaxy S4, left, and an iPhone.
Chris Ratcliffe | Bloomberg | Getty Images

How do I use a messaging app?

Contacting friends with these apps isn't that different from using your phone's texting service. Type a message to your contact and hit send. You'll get a notification when you receive texts, and conversations appear in dialogue form. The catch: Both you and the person you are chatting with must have accounts with the app.

WhatsApp, founded in 2009, simplifies that by syncing your phone number with the app, so all your contacts who have the app are included automatically. There's no need to create a separate account ID, as with other popular messaging platforms.

Setting up an account ID with the other two apps is easy, however, and they also let you do more than message friends by providing private social networks.

WeChat and Line also let you link your account with your Facebook profile. If you register your email address, you can keep the same account and contact list even if you change devices.

What else can I do?

These services go far beyond text or multimedia messages.

Developed in Japan in 2011, Line set off the frenzy of sending stickers, which are larger, more complex versions of instant message icons. Stickers allow you to have an entire conversation in pictures. If you run out of expressions, you can buy more stickers through Line's mobile store. The app also lets you call your contacts for free.

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Call quality can vary depending on your Web connection. So another messaging option, especially if typing is too cumbersome, is voice messages.

Available on WhatsApp, Line and WeChat, voice messaging works like a walkie-talkie. After creating a chat group with one or more contacts, you press and hold the talk button and speak a message before releasing. Rather than a bar, a text box representing your message appears. Everyone in the chat group can press the bar to hear the message as many times as you like. The platforms also support video calls, although quality depends on your Internet connection.

WeChat and Line also let you follow celebrities, news outlets and community organizations. You can message these official accounts privately and, sometimes, get a response.

In addition, the apps have news feeds, similar to Facebook's, that let you see your contacts' photos, links and status updates.

WeChat's feed, called Moments, shows updates and comments only from your contacts. There's also an option to block certain contacts from seeing your news feed.

What will mobile messaging cost me?

WeChat and Line are totally free; WhatsApp charges 99 cents annually after the first year of use. None of these apps have ads.

WeChat and Line also let you send files, which is made even easier with desktop and tablet support.

And there's no hassle when you travel abroad. With an Internet connection, you can still keep in contact with the same people without the hassle of exchanging numbers and paying global fees.

With so many choices, you may want to use multiple accounts across messaging platforms to stay connected.

By Evelyn Cheng, Special to CNBC. Follow her on Twitter: @chengevelyn.