Consequently, is I will see you later formal or informal?
Short Answer
"See you there" and "see you then" are both fine. They are somewhere between formal English (see alternative phrases below) and informal/spoken language, where a "see you" or even "see ya/cheers/cu" might suffice.
Also Know, is later on formal? I would use later in formal or professional communication. Later on is more informal and even if gramatically correct may not fit in some contexts, but I cannot cite a rule.
Similarly one may ask, what to say instead of see you later?
Slang Ways of Saying Goodbye in English
- Later, Laters, or Catch you later. These are slang ways of saying “see you later” which are common among teenagers.
- Peace or Peace out.
- I'm out or I'm out of here.
- I gotta jet, I gotta take off, I gotta hit the road or I gotta head out.
How do you write See you soon in an email?
Expressions with a future focus
I look forward to hearing from you soon / meeting you next Tuesday. I look forward to seeing you soon. I'm looking forward to your reply.