Old

It's unconfirmed, but is speculated to be over 400 years old due to them existing when Belos was not what he was in the series itself

I say like 10,000 years old

9._.

Over 1000 years old. Even if his appearance makes him look like a second grader.

The Collector is such an IPad kid despite the fact that they are possibly thousands of years old

I would say over a thousand years old.

Physically and mentally, he seems to resemble a child that's about 7-9 years old. Now, his actual age... the archivists have apparently existed for a really long time, maybe since the beginning of the Demon Realm's existence. The Collector themselves already existed when Titans were still common and hadn't been wiped out, so... yeah, really old.

My take on how old the collector is like 7 million or something, but the human equivalent of the collector's age would be 7, 8, or 9

@VeggieGoBrrrr