Two ways to encode a place, with very different outcomes
There is a standards-based way to put a location in a QR code and a pragmatic way, and the gap between them is wider than for any other payload type.
The geo: URI (RFC 5870) encodes raw coordinates:
geo:51.5007,-0.1246
A maps URL encodes a link to a specific mapping service:
https://www.google.com/maps/search/?api=1&query=51.5007,-0.1246
The geo: version is elegant, service-neutral, and about 100 characters shorter. It is also the one that fails on iPhones. iOS does not register a handler for the geo: scheme, so scanning a geo: code with the native iOS Camera app typically produces a plain-text result rather than opening Maps. Android handles it properly and offers the user a choice of installed map apps.
Since roughly half of the phones pointed at a printed code in most markets are iPhones, the maps URL is the right default for public-facing material. The generator above produces one. Use geo: only when you control the device fleet — a warehouse, a delivery operation, an internal asset map on Android hardware.
Coordinates or a place name?
A second decision, and the one people get wrong more often.
Coordinates drop a pin at an exact point. They are unambiguous, they work for locations with no address at all — a trailhead, a festival gate, a site entrance in the middle of a field — and they never break because a business rebranded.
A place query (?api=1&query=Tate+Modern+London) resolves through the mapping service's search, which means it shows the venue's listing with opening hours, photos and reviews rather than a bare pin. It also means the result depends on the search index, and can drift or go wrong if the name is ambiguous.
For a business with a listing, the strongest option is a query with a place ID, which pins the result to one specific listing rather than a fuzzy name match:
https://www.google.com/maps/search/?api=1&query=Tate+Modern&query_place_id=ChIJ...
For anything without an address — a gate, a meeting point, a parking area, an emergency assembly point — use coordinates and nothing else.
Precision, and the cost of too many decimal places
Latitude and longitude are usually written with far more precision than anyone needs, and each extra digit adds characters to the payload:
| Decimal places | Approximate precision | Useful for |
|---|---|---|
| 2 | ~1.1 km | Nothing practical |
| 3 | ~110 m | A neighbourhood |
| 4 | ~11 m | A building |
| 5 | ~1.1 m | A specific door or gate |
| 6 | ~0.11 m | Survey work |
Five decimal places is enough for any human navigation task. Copying eight from a spreadsheet adds six characters per coordinate for precision finer than the GPS in the phone can resolve anyway. Trim them.
Also note the sign convention: negative latitude is south of the equator, negative longitude is west of Greenwich. Transposing latitude and longitude — a genuinely common error when copying from different tools — usually lands the pin in the ocean, which at least makes it easy to spot.
Density and print size
A maps URL is a long payload. https://www.google.com/maps/search/?api=1&query=51.50072,-0.12462 is around 65 characters, and query strings contain ?, = and &, all of which force byte mode encoding.
| Payload | Length | Version at level M | Sensible print size |
|---|---|---|---|
geo:51.50072,-0.12462 |
21 | 2 | 2 cm |
| Maps URL with coordinates | 65 | 4 | 2.5 cm |
| Maps URL with name and place ID | 120 | 6–7 | 3.5 cm |
If the code is going on outdoor signage read from several metres, apply the 10:1 rule — a code read from 3 metres wants to be around 30 cm across — and use a short redirect on your own domain to keep the payload small at that size.
What the user actually sees
iOS, scanning a Google Maps URL, opens the link in Safari, which then offers to open the Google Maps app if it is installed. An iPhone user without Google Maps installed stays in the browser and gets the web map, which works but is slower. If your audience is predominantly iOS, an Apple Maps URL (https://maps.apple.com/?ll=51.50072,-0.12462) gives them a smoother path — at the cost of the reverse problem for Android users.
Android opens Google Maps directly when it is installed, which it almost always is.
The honest summary: there is no single URL that opens the user's preferred map app natively on both platforms. A Google Maps URL is the best compromise because it degrades to a functional web map everywhere.
Getting the coordinates right
From Google Maps on desktop: right-click the exact point on the map and the coordinates appear at the top of the context menu, ready to copy.
From Google Maps on mobile: press and hold to drop a pin; the coordinates appear in the search bar at the top.
From a photo: most phone cameras embed GPS coordinates in the image EXIF data. If you took a picture standing at the spot, the location is already in the file.
From an address: search it in any mapping tool, then take the coordinates of the resulting pin — but verify the pin is where you think it is. Address geocoding routinely places pins at the centroid of a building, a plot, or occasionally the wrong end of a long road.
Always test the code by scanning it and following the directions, ideally from a starting point a few kilometres away. A pin that looks correct on a zoomed-in map can still route people to the wrong entrance of a large site.
Where these earn their place
- Event signage and invitations — the venue entrance, the car park, the accessible entrance, each with its own code
- Delivery and trade instructions — the loading bay rather than the shop front, which saves drivers a lap of the building
- Property listings and boards — a pin at the actual property
- Trailheads, campsites, moorings and rural venues where there is no usable postal address
- Emergency assembly points and site plans on construction and industrial sites
- Restaurant and shop windows so passers-by can save the location for later
- Festival and site maps, one code per zone
Frequently asked questions
Why does a geo: code not work on iPhone?
iOS does not register a handler for the geo: URI scheme, so the native Camera app shows the raw text instead of opening Maps. Android supports it properly. For any code scanned by a general audience, use a maps URL rather than a geo: URI.
Should I encode coordinates or an address?
Coordinates for anything without a usable postal address — gates, trailheads, meeting points, car parks — because they are exact and cannot go stale. A place name or place ID for a business with a map listing, because the user gets opening hours and reviews rather than a bare pin.
How many decimal places do I need?
Five, which is about a metre of precision. Six is survey-grade and finer than a phone's GPS can resolve. Copying eight decimal places from a spreadsheet just makes the code denser for no benefit.
Can I make one code that opens Apple Maps on iPhone and Google Maps on Android?
Not directly — a QR code encodes one string. You can achieve it by pointing the code at a URL on your own site that detects the user agent and redirects accordingly, which also gives you scan analytics. For most purposes a Google Maps URL is good enough, since it opens the app on Android and a working web map on iOS.
Does it work without a data connection?
Not reliably. The scan itself works offline, but loading the map needs data unless the user has downloaded offline maps for the area. For rural and remote venues, print the coordinates and a what3words or grid reference as text alongside the code.
Will the code still work if my business moves?
No — the coordinates or URL are fixed in the image. If you expect to move, point the code at a short URL on your own domain that redirects to the map, so you can update the destination without reprinting.
Are the coordinates sent to your servers?
No. The URL is assembled and the code rendered in your browser. Nothing you enter reaches us.