I am in my senior years, and I have considered that when someone wants to go off site to chat it can be a red flag. But, what do younger people think or other cultures, is it a red flag or part of the new normal? And how long is it before being considered appropriate to ask about something like that?
What's your thoughts?

It's a red flag for me if someone wants to chat off site immediately after the first few replies. You need to build trust first. For me, it might take weeks, and sometimes I would be the one to offer to chat off site if there's compatibility between us.

That is a big red flag. If you are a real person and are already chatting in the messages then you can keep chatting. The scammers want to take you to a less secure site. Listen to your gut and you will see the scammers.

Wow it's red flag

it`a Chinese Communist Red Flag.

WhatsApp is not a red flag. Everyone over here uses that. It's considered really really weird when you don't have it.
It doesn't have anything to do with age either as everyone uses it, young AND old. It's the most common app used by everyone over here.
Fact that it isn't used so much in the US doesn't make it a red flag.

The matter of going off-site could be a red flag. If this is suggested almost immediately, then yes, it is a red flag.
If it is asked/suggested after ample conversation it isn't.
What is deemed 'enough' is personal and depends on the quality of the conversation.

I consider any contact, from anyone,
to be a "red flag".

yes i agree sir

Do video call asap with them

chatting here for days or even weeks and then discover that the person you chat with is a scammer is pointless... I go straight on WhatsApp, video call problem solved, if they avoid that then bye bye

I personally think it depends on the situation or the site your on. i've agreed to go on other platforms because it was getting too expensive, charging by each text, monthly subscriptions, paying to see who liked you.
its ridiculous. so some times you have to take a chance. like here for instance. meeting people isn't what it use to be..

i guess when both fell comfortable only chat there

Right After "HI, MY NAME IS SO AND SO"
Comes Lets Go to "HANGOUT" or Google Chat.

I Wrote in My Profile that I do Not Go to Any of those Sites.

So you don't mind handing out your number to strangers ?

You are Right.
I am Also on the Dating Site >> TruMingle.

It depends on how quickly they want to move off site. If you've been chatting with someone for several messages and you can tell they are legit (not just canned, generic messages), why not move on to a phone call/video chat or start texing on WhatsApp?

I love life, my happiness from the happiness of others

The platforms are not the issue . Human intent is and why they want to lure you off site . If you have established trust .. go for it

it can be a red flag, but sometimes you want the same thing better to ask it from the start then to find out it is a red flag

WhatsApp is definitely a red flag