When comparing WhatsApp vs Gboard - the Google Keyboard, the Slant community recommends Gboard - the Google Keyboard for most people. In the question“What are the best Material Design apps?” Gboard - the Google Keyboard is ranked 14th while WhatsApp is ranked 34th. The most important reason people chose Gboard - the Google Keyboard is:
The Google Keyboard supports swiping along the keyboard to spell out whole words.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Straightforward interface
The interface is very simple, fast and easy to use. You can start using it as soon as the app has been downloaded - it does not require setting anything up or registering. You can communicate with anyone in your contacts list that also uses WhatsApp. Includes useful features like seeing when a contact is currently available or typing.
Pro Widely used
WhatsApp reported 1.5 billion users in 2018. Your friends are most likely already using WhatsApp, so it's easy to get setup.
Pro Effortlessly builds your contacts by using your phone number as identification
WhatsApp will automatically find all of your contacts currently using Whatsapp and add them to your contacts. This makes it really easy to setup and given that it's the most popular messaging app it's likely that a lot of your contacts are already using it.
Pro Message mirroring on web app
WhatsApp can be used from the desktop via Chrome, Firefox and Opera browsers. Accessing it requires using the Android app to scan the QR code that's presented on web.whatsapp.com.
Pro Signal protocol
Whatsapp uses the state-of-the-art Signal protocol that ensure strong end-to-end encryption.
Pro One-on-one texts can be encrypted
WhatsApp has implemented end to end encryption for messages sent on it's service. Even WhatsApp has no way to read a users messages.
Pro Swipe support
The Google Keyboard supports swiping along the keyboard to spell out whole words.
Pro Learns preferred words
After using a gesture a few times and clicking the correct word, Google Keyboard learns that the gesture should result in the word you've manually selected as the correct word. Swype doesn't seem to learn this, so even after 100 times clicking 'this' instead of 'thesis', it still produces 'thesis', where Google Keyboard learns that you meant to say 'this'.
Pro Material Design
Google Keyboard has material design themes the user can skin the keyboard with.
Pro Swipe to punctuation
Hold down the key in the lower left hand corner and a keyboard if punctuation appears. Swipe over to the one you want, lift your finger, and the original keyboard pops back. It's very fast, and makes it much easier to spot the punctuation mark you want - instead of trying to squint at the secondary symbols in the keys.
Pro 100% free from Google
This keyboard is not a free trial nor will it hold back any new features to sell you a paid version. The keyboard is completely 100% free.
Pro Minimalistic design
While other keyboard options may be very functional, their visual design tends to differ from the rest of your Google device. The Google Keyboard was designed by Google and it looks like it.
Pro Fast, low memory usage
Alternative keyboards tend to suck up system resources, often making them nearly unusable on older phones. Google Keyboard is very quick to open when typing and the keys rarely lag.
Pro Has built-in Google search
The keyboard has button that allows searching Google straight from the keyboard, and use the search results in the currently used app.
Pro Emoji search
The GBoard has an emoji search that's very convenient, saves time looking for a specific one if you don't know/remember what category it's in.
Pro Dynamic floating preview
The dynamic floating preview appears while gesture typing. Most gesture keyboards only show the preview above the keyboard in the suggested corrections. The dynamic floating preview is great because it makes it easier to gesture type by keeping your eyes focused on what you are typing.
Pro Can use alternative layouts not just QWERTY
For those that are used to typing on a Dvorak keyboard or prefer not to need multiple key presses to access special symbols they can enable these as additional quick switch options. Using the English PC layout for example gives the user a number row.
Pro One-handed mode
Makes it easier to type with no more than a thumb.
Pro Suggestions don't get worse over time
Google keyboard does not promise to be as "smart" as other keyboards besides offering a personalized dictionary. Surprisingly this is actually a good thing for some because with many "smart" keyboards predictions and corrections actually worsen over time. With Google Keyboard the experience will remain constant because it requires you to manually "touch again to save" before it changes your personal dictionary. This prevents mistakes from becoming part of your personal dictionary.
Pro 120 languages support
Pro GIF support
Pro Cloud backup
Pro Pre-installed on most Android devices
Most Android devices have GBoard installed.
Cons
Con Shares meta data with Facebook
WhatsApp shares your messaging meta data with Facebook if you do not opt-out in the settings. If you use the same phone number for WhatsApp and Facebook, the profiles can easily be linked.
See https://www.whatsapp.com/faq/en/general/26000016
Con Tied to carrier phone number
WhatsApp cannot be used by people without a smart phone with an active cell plan. If your phone is lost or damaged, or if your phone number changes, you cannot get messages sent by friends without them updating your phone number. You cannot send message to them until you are able to get SMS messages at your phone number.

Con Proprietary
Not open source.
Con Hard to migrate history cross platform
Migrating your chat history from Android to iOS or the other way around is not so simple. In some cases it requires a 3rd party app and in some the only way is to migrate specific chats one by one.
Con Web interface uses message mirroring
To use your computer to send messages your phone must be on with a consistent data connection.
Con Single device
You cannot use the same WhatsApp account on multiple devices (e.g. a tablet, a PC and a cellphone). The account is tied to the device with the specific cellphone number. Chat history is deleted when you sign in to a new account, unless you have created a backup.
Con No cloud sync
Messages are not stored on WhatsApp server for privacy and security reasons.
Con Limitation on shareable file sizes
WhatsApp now allows users to share files of any type, but there is still a 16 MB size limit.
Con Typing is not always smooth
Sometimes typing lags.
Con Horrible Word Prediction
Unable to remember frequently used words.
Con Adds periods in random places and there is no way to disable it.
Con Lacks some features
Does not add contacts, does not save clipboard, and doesn't show the correct spelling of words or underline them, even though it's in settings.
Con Very little customization
Google Keyboard allows you to enable or disable
vibrate on keypress
sound on keypress
popup on keypress
double space period
These are pretty useful basic settings but most other keyboards offer more options. Google also allows you to edit the personal dictionary.
Con Restricted customization (few skins)
Con Terrible layout in landscape mode
Con Takes up a lot of storage
If you are using multiple languages and predictive text, the app can use up a lot of storage.
Con Prediction isn't as good as SwiftKey
Con Uses a lot of RAM

Con Symbol order is (slightly) different from full-sized QWERTY keyboard
Instead of the first four symbols being !@#$%^& (i.e. shift+1 through 7 on a QWERTY keyboard), they're @#$%&. This is fine if you know the symbols in your password, but if you're like me and you just hold the SHIFT key and type a long number, you'll have to consult a real keyboard to figure out your password.
Con Other languages not available in transliteration mode
Unlike Google Indic Keyboard where you can type by transliteration, compact, and handwriting, you only get the fixed layout for other languages.
Con It doesn't have arrow keys
Several times it is much better to navigate through a long text using arrow keys than scrolling and tapping the place where you want the cursor to be. SwiftKey has arrow keys (via an option), Gboard has not.
Con Google, via the keyboard app, might be collecting data on us that it then sells to third parties which in turn can use that data to influence us
