The short answer
A GPS-enabled smartphone is typically accurate to about 5 metres (4.9 m) under open sky, according to the US government’s official GPS information site. Accuracy gets worse near tall buildings, under bridges and among trees. For business tracking — which street, which site, which customer — that is more than enough.
What GPS accuracy actually means
A GPS position is an estimate with a margin of error, usually expressed as a radius: “accurate to 5 metres” means the true position is very probably within a 5-metre circle. Good receivers report that estimate alongside each position, which lets software throw away the weak ones.
What makes GPS less accurate
- Tall buildings block and reflect signals (“urban canyons”).
- Tree cover weakens signals.
- Indoors, tunnels and underground car parks — GPS mostly doesn’t work there at all.
- A cold start — the first fix after the phone has been off can be rough.
See what blocks a GPS tracker for the full list.
What’s the most accurate GPS tracker on the market?
For everyday tracking, the differences between decent devices matter less than the conditions they are used in. Surveying-grade dual-frequency receivers reach centimetre accuracy, but they cost far more and aren’t what a business needs to see which job a van is at. Recent flagship phones are also very good: many use several satellite systems (GPS, Galileo, GLONASS, BeiDou) and some use dual frequencies.
What makes the biggest practical difference is what the software does with the positions: discarding poor-accuracy fixes, smoothing jitter and not drawing a parked phone as a scribble.
How accurate is TrackLink?
TrackLink uses each phone’s high-accuracy location mode, discards any position the phone reports as worse than 25 metres, and smooths the rest so routes follow the roads rather than zig-zagging. When a phone is parked, its history stops recording jitter and holds a single settled position.
Is GPS accurate enough for timesheets and disputes?
For “was the engineer at the customer’s address at 9am?”, yes. For “which side of the road were they on?”, not reliably. Treat GPS as strong evidence of where someone was, to within a few metres in the open and a few tens of metres in a dense city centre.
Common questions
How accurate is phone GPS?
Typically about 5 metres in open sky, worse near tall buildings and trees, and unreliable indoors.
Why does my GPS location jump around?
Reflections from buildings and weak signals produce occasional bad positions. Good tracking software filters these out.
Is GPS more accurate than cell tower location?
Much more. Cell tower location can be off by hundreds of metres; GPS is usually within a few metres outdoors.