1. Format message text

You can format your chat message by placing special characters before and after your text.

To bold text use an asterisk *bold*
To italicize text use an underscore _italicize_
To strikethrough text use tildes ~strikethrough~

To switch to a secret FixedSys font use three left slanted apostrophes ```text```
On your Andriod keyboard the left slanted apostrophe character is in the second set of symbol characters.

You can also format text that you already typed by highlighting the text (tapping and holding it) then selecting the format icons that appears on the top of the message box.

2. Change the font size of your chats

Whatsapp has three setting for font size: small, medium and large
Go to Settings > Chats > Font size

3. Get message details

To view when a message was delivered and read:
Long-press on a message, then tap on the "info" icon at the top of your screen.

4. Reply including quote

The Reply feature allows you to respond to a particular message, both in a group and in an individual chat.

Tap and hold the message to highlight, and tap the curved arrow at the top of the chat. The highlighted text is included in your reply.

5. Mark chats as unread

When you've read a message but cannot reply to it right away, you can set a visual reminder by marking it as unread.

Long-press the conversation, tap on the WhatsApp menu (three dots icon in the top-right) and choose "Mark as unread".

6. Star a message for quick access

If you would like to bookmark a specific message for easy access, long-press on a message, then tap on the "star" icon.
To access all your starred messages, tap on the WhatsApp menu (three dots icon in the top-right) and choose "Starred messages".

7. Draw on your photos before sending

When you take a photo or pick a photo you want to send from your gallery, use the icons at the top of the screen to add words, draw pictures, or add an emoji. There are options to filter your photo and rotate it.

8. Pin popular chat groups

If there's one group chat you use more than any other, you can make sure it's always at the top of the list by pinning it there.

Long press on the contact and then click the pin icon up top.

9. Mute conversations

If you are on a public chat and you need a break from the conversation, but you do not want to leave the chat, you can mute the conversation for a specific time period.

Long-press on a chat, then tap on the crossed-out speaker icon at the top of the screen. You can choose 8 hours, 1 week, 1 year.

10. Custom notifications

Instead of having the same alert sound for every incoming message, you can set custom alerts for individual contacts. Doing so makes it easier to know who messaged you without looking at your phone.

11. Send your chat conversation via email

You can send all the chat history, images and videos of a specific chat to your email account.
While viewing your chat, tap on the WhatsApp menu (three dots icon in the top-right) and choose more> Email chat.
You can email the text conversation with or without media attachments.

12. Disabling read receipts for all messages

WhatsApp's ticks-based system shows when your sent messages have been delivered (one grey tick), received (two grey ticks) and read (two blue ticks).

You can disable read receipts by going to:
Settings > Account > Privacy > Read Receipts
and uncheck the box.
Note: If you disable read receipts you lose the ability to see when your own sent messages have been read.

13. Read messages without the blue ticks appearing on your friend's screen without disabling read receipts.

Before you run Whatsapp, switch your phone to airplane mode, open Whatsapp and read the message. Close Whatsapp before turning off airplane mode.

14. Hide your 'last seen' time

You can prevent your contacts from finding out when you were last online by navigating to:
Settings > Account > Privacy > Last Seen.
You can change the settings to "Everyone", "My Contacts", "Nobody".
Note: As with disabling read receipts, hiding your 'last seen' time also prevents you from seeing anybody else's status.

15. Share your location

During a chat conversation, tap the attachment icon (paperclip) on the chat typing line. Choose Location from the drop-down menu. You can choose to send your position using GPS, or choose from a list of places or search through the map.

16. Create homescreen shortcuts to conversations

You can create shortcuts to popular chats and place them on your phone's homescreen. This is useful if there are certain people you chat to often.

Tap and hold on the chat (group or individual) of your choice and a tab pops up. Select the "Add Shortcut" option and the chat link appears as the person's profile photo on your phone's homescreen.

17. Mass message your contacts

You can send a message to a list of contacts without starting a chat group where everyone can interact. This works like sending out an email message using BCC. Each person gets the same message. They do not see a list of the receipents. You can create a broadcast list of 2 to 256 contacts.

On the Whatsapp menu (3 dots) choose "New broadcast".
Select the contacts you would like to send the message to.
Create and send a message.

18. Backup WhatsApp conversations

Go to Settings > Chats > Chat Backup
In the settings, you can specify the backup to be done only when you are connected with Wi-Fi. This saves you money if you pay for data transfers.

19. Block Contacts

You can block any WhatsApp user from contacting you again.

While viewing the chat, tap on the WhatsApp menu (three dots icon in the top-right) and choose More> Block.

20. Limit data usage

You can control how much data you transfer through on WhatsApp by limiting the types of media you automatically download on a mobile connection.

Go to Settings > Data Usage and choose your option.