Does StandBy Mode affect GPS tracking on iPhone?

The short answer

No. StandBy is a lock screen layout — a clock, a widget or two, sometimes a photo, filling the screen instead of the display going dark — and it has no connection to the GPS chip or the app recording a route underneath it. A track keeps logging points at the same rate whether the phone is showing StandBy, sitting on a plain lock screen, or fully dark.

There is also a reason not to worry about the battery angle here the way you might with other always-on-style settings: StandBy only ever appears while the phone is charging. If it is on screen at all, the phone is already plugged into a cable or a battery pack, so whatever small amount of power the display draws while it is lit is not coming out of the same battery the rest of the hike depends on.

What StandBy actually is

StandBy is a screen mode that shows up on its own when an iPhone is charging, locked, and turned sideways — set on a table, propped in a stand, resting against a rock. Instead of the screen going black, it fills with a large clock face, a widget or two, or a slideshow of photos, and switches to a dim, red-tinted look in a dark room so it does not light up a whole tent. Pick the phone up, unplug it, or turn it back to portrait and it drops straight back to a normal lock screen.

Why it has nothing to do with the track underneath

Recording a route and drawing a clock on the lock screen are two different jobs handled by two different parts of the phone. The GPS chip keeps receiving satellite signals and the recording app keeps logging points on its own schedule regardless of what the display happens to be showing — a route recording through the screen going dark, showing a normal lock screen, or showing StandBy all produce the same track, with points spaced the same way. StandBy was built to run on top of whatever is already happening on the phone, not to change how any background task behaves, recording apps included.

Why the usual battery worry does not apply here

Always-On Display and a screen simply left on both cost battery because they draw power without anything else supplying it. StandBy is different in one specific way: it is only ever showing because the phone is plugged in. A phone sitting in StandBy at a campsite is already pulling power from a battery pack or a wall charger, not spending down the same charge the rest of the day's hike depends on. If a battery pack is small enough that every bit of its output matters, a screen lit up the whole time it is connected does draw a little more from that pack than a screen left dark — but that is a question about how far the power bank stretches, not about the phone's own battery or about the GPS track.

Things that trip people up

• Assuming a phone lighting up in StandBy mid-charge means GPS tracking has restarted or paused — it has not; StandBy is a display change, and the track underneath was never touched.
• Worrying that StandBy is quietly draining the phone's own battery the way Always-On Display does — it cannot, because StandBy only appears while the phone is already connected to power.
• Turning StandBy off before a multi-day trip expecting the track to record any differently afterward — the track looks identical either way; only the lock screen's appearance changes.
• Confusing StandBy with the screen just staying on — StandBy is a specific lock screen layout that needs charging and a sideways phone, not a general always-awake setting.

Where TrailCam fits in

TrailCam keeps recording a route in the background regardless of what the lock screen is doing, StandBy included, so a phone propped up and charging at a lunch stop or overnight on a multi-day trip tracks exactly the same as one sitting untouched in a pocket. Whether StandBy is worth using on a given trip is purely a matter of wanting a clock visible while the phone charges — it has no bearing on the route itself. TrailCam is free to download.