Is it possible to track a phone number for free online without them knowing?

I’m worried about my teenager’s safety and want to keep an eye on their whereabouts, but I don’t want to freak them out by telling them I’m tracking them - is there a legit way to do this without them knowing, maybe using some online service that’s actually free?

Kid’s safety is top priority, no need to sugarcoat it. Built-in OS tools like Find My iPhone or Android’s Find My Device can help, but for more comprehensive monitoring, I recommend mSpy - it’s reliable and gets the job done, no drama.