Thanks for the detailed guide, I didn't even know that you can sign messages in a meta mask, I just didn't pay attention to it.
Now when I send transactions I will have fun this way)
Topic: How To Send Message in Blockchain Transaction (Read 183 times)
Thanks this can be valuable. Do you know how much data you can put into the transaction ie. what is the character limit of the message? Also, do you know if the limit is different for different blockchains eg. ETH vs Poly?
Cools stuff, maybe you can add if what eth explorer is compatible for this message stuff. Or maybe all of the existing eth explorers integrate it too?
You can try other blockchains too, I think that are compatible with the ETH, BEP20, MATIC chains. 
Cools stuff, maybe you can add if what eth explorer is compatible for this message stuff. Or maybe all of the existing eth explorer integrates it too?
Blockchain only supports Hexa Decimal code for sending the message, so we need to change our messages into hexadecimal coding.
Blockchains are simply raw bytes and the building components called transactions are raw bytes that can store arbitrary bytes in a certain way. Hexadecimal is just an encoding used to represent those bytes. The reason why you have to convert your UTF8 encoding to HEX encoding is because the tool you are using is dumb and doesn't have the option to directly convert UTF8 to bytes so you have to first convert UTF8 to bytes elsewhere then convert it to HEX then the tool converts HEX to bytes!
Blockchain only supports Hexa Decimal code for sending the message, so we need to change our messages into hexadecimal coding.
Blockchains are simply raw bytes and the building components called transactions are raw bytes that can store arbitrary bytes in a certain way. Hexadecimal is just an encoding used to represent those bytes. The reason why you have to convert your UTF8 encoding to HEX encoding is because the tool you are using is dumb and doesn't have the option to directly convert UTF8 to bytes so you have to first convert UTF8 to bytes elsewhere then convert it to HEX then the tool converts HEX to bytes! 
Thank you wtsimis for the detailed guide.
I just want to comment on this point:
Storing data on the blockchain might be useful in some cases but it's not recommended. Just think of those who run full nodes and will have to store unnecessary data on their machines.
I just want to comment on this point:
Now come to metamask, select any address that you wanna send a message to
By doing this, you are not really sending the message to a person/address in particular. The message will be saved on the blockchain and any one can read i not only the recipient. Storing data on the blockchain might be useful in some cases but it's not recommended. Just think of those who run full nodes and will have to store unnecessary data on their machines.
Many of us know that a couple of months ago Poly Network got hacked, where they communicate with the hacker through Blockchain messages. So, today I gonna show you, how to send any type of message through blockchain. We can send them through metamask. Before sending messages from the metamask, you need to change some settings in the metamask.
Go to wallet settings→ advanced→ scroll down and turn on ''Hex Data''
Blockchain only supports Hexa Decimal code for sending the message, so we need to change our messages into hexadecimal coding. Many sites convert to hexadecimal, I prefer https://codebeautify.org/string-hex-converter.
Write whatever text you want, it'll convert your text into code.
Now come to metamask, select any address that you wanna send a message to, put the amount that you wanna send in the hex data, give the coded message, and click send.
After confirmation, view the transaction on the explorer,
click to see more,
you can see that your sent coded message, now click on the
view input as UTF-8, then you can see the message that you have sent.
Go to wallet settings→ advanced→ scroll down and turn on ''Hex Data''
Blockchain only supports Hexa Decimal code for sending the message, so we need to change our messages into hexadecimal coding. Many sites convert to hexadecimal, I prefer https://codebeautify.org/string-hex-converter.
Write whatever text you want, it'll convert your text into code.
Now come to metamask, select any address that you wanna send a message to, put the amount that you wanna send in the hex data, give the coded message, and click send.
After confirmation, view the transaction on the explorer,
click to see more,
you can see that your sent coded message, now click on the
view input as UTF-8, then you can see the message that you have sent.
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