If you follow someone and that person follows you back, you will be able to see if that person is online at that time or not. You will see a green dot next to their photo and the status "Active Now".
Instagram's fake "Active Now" Solution: Why does Instagram show "Active" when you're not?
However, if a person is not following you or has not sent you a direct message, you will not be able to see this information. Unfortunately, the active status on Instagram isn't always accurate, and here's why.
If not enough time has passed for the Active status to update, it may show that someone is active when they are not. There must be a gap of about 10 minutes before someone's activity status is displayed correctly.
If someone stopped using Instagram a few minutes ago and it says they're active when they're not, you may need to give it about 10 minutes before their true active status is reflected.
