If you use abbreviations as a tactic for speed in text communication or because they are a code that older people don’t quite understand, in this page you will found the dominating abbreviations.
These words may not be as new as some may think. The OED found that OMG was first used in 1917, in a personal letter. LOL has been around since 1960, but it meant something quite different, with the letters standing for Little Old Lady.
“The intention is usually to signal an informal, gossipy mode of expression, and perhaps parody the level of unreflective enthusiasm or overstatement that can sometimes appear in online discourse, while at the same time marking oneself as an ‘insider’ au fait with the forms of expression associated with the latest technology.”

AFAIK As far as I know
AFK Away from keyboard
AMA Ask me anything
BFF Best friends forever
BRB Be right back
BTW By the way
DGAF Don’t give a f***
DTF Down to f***
FBF Flashback Friday
FBO Facebook Official
FFS For f***’s sake
FML F*** my life
FOMO Fear of missing out
FTW For the win
FYI For your information
GG Good game
GTFO Get the f*** out
GTG Got to go
HBD Happy birthday
HMB Hit me back
HMU Hit me up
ICYMI In case you missed it
IDC I don’t care
IDK I don’t know?
IKR I know right?
ILY I love you
IMO In my opinion
IRL In real life
JK Just kidding
LMAO Laughing my a** off
LMK Let me know
LMS Like my status
LOL Laugh out loud
MCM Mancrush Monday
NM Not much
NSFW Not safe for work
NVM Nevermind
OMG Oh my god
OMW On my way
OOTD Outfit of the day
POTD Photo of the day
PPL People
PTFO Passed the f*** out
ROFL Rolling on the floor laughing
ROFLMAO Rolling on floor laughing my a*** off
SFW Safe for work
SMFH Shaking my f***ing head
SMH Shaking my head
STFU Shut the f*** up
TBH To be honest
TBT Throwback Thursday
TGIF Thank God it’s Friday
THX Thanks
TMI Too much information
TTYL Talk to you later
TTYN Talk to you never
TTYS Talk to you soon
Txt Text
WCW Womancrush Wednesday
WTF What the f***?
YOLO You only live once