What’s the difference: RCS, WhatsApp, Line, and Facebook Messenger

Whether you plan to incorporate your first instant messaging service into your tech stack or add to your current omnichannel communication strategy, read on to learn about the key differences among RCS, WhatsApp, Line, and Facebook Messenger.

Many instant messaging services nowadays have a variety of features in addition to messaging, such as video and voice calls, multimedia transfer, typing indicators, and more. Some of the most prominent services include RCS, WhatsApp, Line, and Facebook.

So how do you know which one to use? Learn the differences below and see how you can leverage each channel for your business.

Rich Communication Services (RCS)

RCS is an innovative version of SMS with features similar to online messaging platforms, which gives you the flexibility to build app-like experiences for your customers. However, unlike the others, RCS messages will be converted to an SMS and delivered that way if an internet connection is not available or if the recipient is a non-RCS enabled user.

To send and receive RCS messages, you need:

  • An Android device (Not yet available on iOS)
  • A data plan with a carrier that supports (and has enabled) the protocol
  • A messaging app that’s built to comply with GSMA’s Universal Profile

How businesses can leverage RCS:

RCS can be used for alerts, marketing, appointment bookings, and more. It has the ability to send rich media content like interactive maps, QR boarding tickets, and higher resolution videos and images directly inside your RCS message. You can also embed suggested replies and action buttons to your messages, streamlining your communications with your customers.

One caveat of RCS is that not all carriers have adopted the technology, so the audience is smaller than other instant messaging services. However, more and more carriers are beginning to do so. For more information on the current global RCS Operators, look at our related blog article.


With a global user base of 2 billion people, many users have already adopted WhatsApp as one of their main communication channels.

Unlike SMS and RCS, an internet connection is required to use any of its functions, but WhatsApp will save all recent messages if they were offline and notify them the next time they are online.

To send and receive WhatsApp messages, you need:

  • A mobile device with a valid phone number
  • An internet connection
  • The WhatsApp messaging app

How businesses can leverage WhatsApp:

Many businesses use this channel to talk to their target leads and customers directly: answering any product questions, booking appointments, or taking orders.

Small businesses can choose to leverage the WhatsApp Business app, which is free to use. Some features of the WhatsApp Business App include quick replies with saved message templates, automated messages, user tagging, and more.

WhatsApp Business app only allows one phone number (mobile or landline) for each account. This means that you will need another phone number to separate your personal and business conversations, making it inadequate for service teams where there’s more than one user.

Medium and large businesses can use the WhatsApp Business API, which is more scalable and suitable for larger teams. The API contains many of the same features as WhatsApp but can be integrated within your own systems and allows you to programmatically send and receive messages.

The API does not have its own user interface like the WhatsApp Business App and must be integrated with an existing software. In addition to set up costs and monthly fees that business partners may charge, there is also a cost per message depending on your messaging volume and when you get back to a customer.

When using the API, all messages received from a customer are free; however, there is a 24-hour “Customer Care Window” for you to reply back. Any messages sent after 24 hours of receiving a message must be a template message and will be charged accordingly.

Find more information on the message list prices here. Currently, the WhatsApp Business API is on a limited public preview. You can either submit a request directly to Facebook or work with a Facebook Business partner like us. If you’re interested, join our waitlist.


Line functions both as a communications platform and a full-featured social network. It allows users in certain regions to complete everyday tasks such as hailing taxis, ordering food, and paying at retail stores.

An internet connection is required to use many of these features and businesses will have to register for a Line Official Account to take advantage of other features such as message tagging, user segmentation, auto-response messages, keyword triggers, loyalty cards and more.

To send and receive Line messages, you need:

  • A mobile device with a Line account
  • An internet connection
  • The Line app or a browser

How businesses can leverage Line:

Line is unique compared to other messaging services as it offers more in-person features. For example, in certain regions, companies can send push notifications to customers walking into a store. This allows brick and mortar stores to send timely promotions and product information through their official account.

The cost to create an official account is free, but once a business reaches their message limit, they will need to upgrade to a paid plan. More information on pricing can be found here. (Please note that different regions have different plans, features, and pricing.)

One caveat to this platform compared to other instant messaging services is the inability to import your own contacts even if you have a customer’s phone number or account ID. All users must add your business as a friend before you can talk to them.

You can reply to a customer via the LINE platform (mobile or desktop) using the Chat option or using the LINE messaging API, but you can’t do both at the same time. You must set your account to either Chat mode or Bot mode.

Last but not least, you can also run ads with LINE advertising to acquire new leads for your business, direct users to your website via the customised menu within your chats, and create loyalty cards to increase customer retention.

Facebook Messenger

Facebook Messenger, or Messenger, is an instant messaging app developed by Facebook. It leverages a user’s Facebook network so that users can reach people privately without needing their phone number. Users can use Messenger through a Facebook account or sign up directly on Messenger with a valid phone number.

An internet connection is required to use any of its functions, but a user who is offline will still receive all messages or interactions the next time they log in.

To send and receive Messenger messages, you need:

  • A Facebook account or a Facebook Messenger account
  • An internet connection
  • The Facebook Messenger app or a browser

How businesses can leverage Messenger:

Businesses can use Messenger to communicate directly with customers, market their products and services, automate messages, and more. Personalisation in automated messages is also easier to implement with the built-in features from Facebook.

You can respond to message enquiries via the Facebook Messenger interface or by using the Messenger Platform API. Facebook Messenger allows businesses to respond freely to incoming messages within 24 hours of receiving a message. After this 24 hour window, you will only be able to use message tags or create sponsored messages to reach your customers. Find more information on the platform’s policy here.

Messenger is fully compatible with Facebook for Business. If you already use Facebook ads as part of your marketing strategy, you will be able to easily adapt your ads for Messenger.

Comparison table: RCS, WhatsApp, Line and Facebook Messenger:

RCS WhatsApp Line Facebook Messenger
Active User Count 310 million 2 billion 165 million 1.3 billion
Internet Connection Required If a Wi-Fi or mobile data connection is not available, messages will be sent as SMS.
Phone Number Required
Voice & Video Call Function
Image & Video Files
Device Restrictions Android Only
iOS Pending
WhatsApp Enabled Only Send speed for non-Line users is slower by 10x Facebook Messenger Enabled Only
Key Free Features
WhatsApp Business App for Small Businesses

Unlimited replies within Customer Care Window

WhatsApp Business API
Line Official Account registration

Up to 500 messages per month (region dependent)

Line Messaging API
Personalisation based on Facebook user data

Messenger Platform API
Key Paid Features TBD Click to WhatsApp Ads via Facebook Ads Manager

Templated message replies outside of customer care window
Advertising options

Premium IDs

Monthly plans based on messaging volume
Advertising options through the Facebook Ads Manager

Message tags or sponsored messages outside of customer care window

Combining it all together

So what instant messaging service should you use? This will depend on who you want to reach! It is important to narrow down your business goals and evaluate how and which instant messaging service can add value to your company.

Decide where most of your target audience is and meet your customers where they already are. This will eliminate the friction created when a user is forced to adopt new technology and create a better brand experience.

Different regions and user demographics will also likely use different instant messaging services. In order to target these different users, consider adopting an omnichannel communication strategy.


  1. Facebook for Business
  2. Facebook for Developers
  3. Freshtrax Blog
  4. GMS Blog
  5. Hootsuite Blog
  6. Line
  7. Statista
  8. WhatsApp
Whether you want to use one instant messaging service or implement many of these into your strategy, Sendsei can help scale your communications. Start by signing up for a free 14-day trial. No obligations. No credit card needed.