come online
1. To become active or begin operating. We've had the building finished for days now, but we're still waiting for the power to come online. Hundreds of new factories are slated to come online over the next year, which will bring a much-needed boost to the economy.
2. To log onto the Internet, usually meaning some social communication service thereof. I'm just waiting for my dad to come online, I haven't spoken to him in weeks!