The Open Location Code (OLC) is a geocode based in a system of regular grids for identifying an area anywhere on the Earth.[1] It was developed at Google's Zürich engineering office,[2] and released late October 2014.[3] Location codes created by the OLC system are referred to as "plus codes".
Plus Codes logo
Open Location Code is a way of encoding location into a form that is easier to use than showing coordinates in the usual form of latitude and longitude. Plus codes are designed to be used like street addresses, and may be especially useful in places where there is no formal system to identify buildings, such as street names, house numbers, and post codes.[4]
Plus codes are derived from latitude and longitude coordinates, so they already exist everywhere.[5] They are similar in length to a telephone number – 849VCWC8+R9, for example – but can often be shortened to only four or six digits when combined with a locality (CWC8+R9, Mountain View). Locations close to each other have similar codes. They can be encoded or decoded offline. The character set avoids similar looking characters, to reduce confusion and errors, and avoids vowels to make it unlikely that a code spells existing words. Plus codes are not case-sensitive, and can therefore be easily exchanged over the phone.[6]
Since August 2015, Google Maps supports plus codes in its search engine.[7] The algorithm is licensed under the Apache License 2.0.[8] and available on GitHub.[9]
Google has shown practical usage of plus codes for addressing purposes in Cape Verde,[10] parts of Kolkata,[11] and the Navajo Nation.[12] Since the COVID-19 pandemic the usage of Plus Codes as government recognized identification of housing in India has grown significantly.[13]
The Open Location Code system[14] is based on latitudes and longitudes in WGS84 coordinates. Each code describes an area bounded by two parallels and two meridians out of a fixed grid, identified by the South-West corner and its size. The largest grid has blocks of 20 by 20 degrees (9 rows and 18 columns), and is divided in 20 by 20 subblocks up to four times. From that level onwards division is in 5 by 4 subblocks. The table shows the various block sizes at their maximum near the equator. The block width decreases with distance from the equator.
Block sizes of Open Location Codes
Code length
2
4
6
8
+
10
11
Block size
20°
1°
0.05° (3′)
0.0025° (9″)
0.000125° (0.45″)
Approximately
2200 km
110 km
5.5 km
275 m
14 m
3.5 m
The full grid uses offsets from the South Pole (–90°) and the antimeridian (–180°) expressed in base 20 representation. To avoid misreading or spelling objectionable words, the encoding excludes vowels and symbols that may be easily confused with each other. The following table shows the mapping.
Mapping of Open Location Codes
Base 20 digit
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Code digit
2
3
4
5
6
7
8
9
C
F
G
H
J
M
P
Q
R
V
W
X
The code begins with up to five pairs of digits, each consisting of one digit representing latitude and one representing longitude. The biggest blocks have just two digits. After 8 digits, a plus sign "+" is inserted in the code as a delimiter to aid with visual parsing. After 10 digits at each subdivision, subblocks are coded in a single code digit as follows:
Division of subblocks in Open Location Codes
longitude →
latitude →
R
V
W
X
J
M
P
Q
C
F
G
H
6
7
8
9
2
3
4
5
Areas larger than an 8-digit block can be specified by replacing an even number of trailing digits before the + sign with the digit 0, with nothing after the + sign.
Example
Consider, for example, zooming in on the Merlion (N 1.286785, E 103.854503) in Singapore. It lies in the block around the equator bounded by -10° South and +10° North, and between 100° and 120° East. It has offsets 80° from the South Pole, and 280° from the anti-meridian; or, 4 and 14 as first base-20 digits, coded as "6" and "P". Thus, the code is "6P". This may be padded as 6P000000+
Now, refine this block to a subblock between 1° and 2° N and 103° and 104° E. This adds 11° and 3° to the SW corner. So the base-20 coordinate codes added are "H" and "5". The result is padded to 6PH50000+.
After four further refinements, one lands on Merlion park as 6PH57VP3+PR.
The next step requires us to divide the square so far used, to refine the position into a 4-by-5 grid, and finding the cell to which the coordinates are pointing. This is the cell named "6". Therefore, the resulting Open Location Code is: 6PH57VP3+PR6.
Common usage and shortening
It is common to omit the first 4 characters from the code and add an approximate location, such as a city, state, or country. The above example, then, becomes 7VP3+PR6 Singapore. This is supported by the Google Maps app and the https://plus.codes website, and also by non-Google apps. These short forms of Plus Codes can be used in lieu of a house number in a neighborhood.
Shortened codes can no longer be unambiguously encoded or decoded offline without context. The specification doesn't rely on any specific database of contextual reference location place names and their exact locations. But the software requires access to some other information which clearly narrows the possibilities to within about 40 km of the referenced location. That could be done for example via a named reference location which can somehow be mapped to a nearby geolocation. Or if it is known that the plus code is sufficiently nearby, and the coordinates of the current location is available to the decoding software, that can be used.[15][16]
References
^"Plus codes". Plus.codes. Retrieved 3 November 2018.
^. Openlocationcode.com. Archived from the original on 1 March 2018.
^See Open Location Code Github and Open Location Code forum.
^The Open Location Code website provides an overview. The document "An Evaluation of Location Encoding Systems" provides a rationale.
^Specification: "Open Location Code: An Open Source Standard for Addresses, Independent of Building Numbers And Street Names"
^"Open Location Code: Addresses for everything, everywhere". Google-opensource.blogspot.ch. Retrieved 3 November 2018.
^"Plus codes: A new way to help pinpoint places on the map". Google-latlong.blogspot.in. Retrieved 3 November 2018.
^"google/open-location-code". GitHub.com. Retrieved 3 November 2018.
^"google/open-location-code". GitHub.com. Retrieved 3 November 2018.
^"Delivering mail where the streets have no name". Google Africa Blog. December 1, 2016.
^"Plus Codes | Addressing in Kolkata" – via YouTube.
^"The Navajo Nation is getting addresses, thanks to an open-source mapping program used in urban India". The Salt Lake Tribune. 2019-10-25.
^"The Address of the Future". Reasons to be Cheerful. July 15, 2022.
^"google/open-location-code". GitHub. Retrieved 3 November 2018.
^"What's Wrong with Open Location Code? - QA Locate". 2019-09-24. Retrieved 2022-11-07.
^"Open Location Code: An Open Source Standard for Addresses, Independent of Building Numbers And Street Names". GitHub. 2019-04-21. Retrieved 2022-11-25.
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This article s use of external links may not follow Wikipedia s policies or guidelines Please improve this article by removing excessive or inappropriate external links and converting useful links where appropriate into footnote references October 2021 Learn how and when to remove this template message The Open Location Code OLC is a geocode based in a system of regular grids for identifying an area anywhere on the Earth 1 It was developed at Google s Zurich engineering office 2 and released late October 2014 3 Location codes created by the OLC system are referred to as plus codes Plus Codes logo Open Location Code is a way of encoding location into a form that is easier to use than showing coordinates in the usual form of latitude and longitude Plus codes are designed to be used like street addresses and may be especially useful in places where there is no formal system to identify buildings such as street names house numbers and post codes 4 Plus codes are derived from latitude and longitude coordinates so they already exist everywhere 5 They are similar in length to a telephone number 849VCWC8 R9 for example but can often be shortened to only four or six digits when combined with a locality CWC8 R9 Mountain View Locations close to each other have similar codes They can be encoded or decoded offline The character set avoids similar looking characters to reduce confusion and errors and avoids vowels to make it unlikely that a code spells existing words Plus codes are not case sensitive and can therefore be easily exchanged over the phone 6 Since August 2015 Google Maps supports plus codes in its search engine 7 The algorithm is licensed under the Apache License 2 0 8 and available on GitHub 9 Google has shown practical usage of plus codes for addressing purposes in Cape Verde 10 parts of Kolkata 11 and the Navajo Nation 12 Since the COVID 19 pandemic the usage of Plus Codes as government recognized identification of housing in India has grown significantly 13 Contents 1 Specification 2 Example 3 Common usage and shortening 4 References 5 External linksSpecification EditThe Open Location Code system 14 is based on latitudes and longitudes in WGS84 coordinates Each code describes an area bounded by two parallels and two meridians out of a fixed grid identified by the South West corner and its size The largest grid has blocks of 20 by 20 degrees 9 rows and 18 columns and is divided in 20 by 20 subblocks up to four times From that level onwards division is in 5 by 4 subblocks The table shows the various block sizes at their maximum near the equator The block width decreases with distance from the equator Block sizes of Open Location Codes Code length 2 4 6 8 10 11Block size 20 1 0 05 3 0 0025 9 0 000125 0 45 Approximately 2200 km 110 km 5 5 km 275 m 14 m 3 5 mThe full grid uses offsets from the South Pole 90 and the antimeridian 180 expressed in base 20 representation To avoid misreading or spelling objectionable words the encoding excludes vowels and symbols that may be easily confused with each other The following table shows the mapping Mapping of Open Location Codes Base 20 digit 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19Code digit 2 3 4 5 6 7 8 9 C F G H J M P Q R V W XThe code begins with up to five pairs of digits each consisting of one digit representing latitude and one representing longitude The biggest blocks have just two digits After 8 digits a plus sign is inserted in the code as a delimiter to aid with visual parsing After 10 digits at each subdivision subblocks are coded in a single code digit as follows Division of subblocks in Open Location Codes longitude latitude R V W XJ M P QC F G H6 7 8 92 3 4 5Areas larger than an 8 digit block can be specified by replacing an even number of trailing digits before the sign with the digit 0 with nothing after the sign Example EditConsider for example zooming in on the Merlion N 1 286785 E 103 854503 in Singapore It lies in the block around the equator bounded by 10 South and 10 North and between 100 and 120 East It has offsets 80 from the South Pole and 280 from the anti meridian or 4 and 14 as first base 20 digits coded as 6 and P Thus the code is 6P This may be padded as 6P000000 Now refine this block to a subblock between 1 and 2 N and 103 and 104 E This adds 11 and 3 to the SW corner So the base 20 coordinate codes added are H and 5 The result is padded to 6PH50000 After four further refinements one lands on Merlion park as 6PH57VP3 PR The next step requires us to divide the square so far used to refine the position into a 4 by 5 grid and finding the cell to which the coordinates are pointing This is the cell named 6 Therefore the resulting Open Location Code is 6PH57VP3 PR6 Common usage and shortening EditIt is common to omit the first 4 characters from the code and add an approximate location such as a city state or country The above example then becomes 7VP3 PR6 Singapore This is supported by the Google Maps app and the https plus codes website and also by non Google apps These short forms of Plus Codes can be used in lieu of a house number in a neighborhood Shortened codes can no longer be unambiguously encoded or decoded offline without context The specification doesn t rely on any specific database of contextual reference location place names and their exact locations But the software requires access to some other information which clearly narrows the possibilities to within about 40 km of the referenced location That could be done for example via a named reference location which can somehow be mapped to a nearby geolocation Or if it is known that the plus code is sufficiently nearby and the coordinates of the current location is available to the decoding software that can be used 15 16 References Edit Plus codes Plus codes Retrieved 3 November 2018 Open Location Code Openlocationcode com Archived from the original on 1 March 2018 See Open Location Code Github and Open Location Code forum The Open Location Code website provides an overview The document An Evaluation of Location Encoding Systems provides a rationale Specification Open Location Code An Open Source Standard for Addresses Independent of Building Numbers And Street Names Open Location Code Addresses for everything everywhere Google opensource blogspot ch Retrieved 3 November 2018 Plus codes A new way to help pinpoint places on the map Google latlong blogspot in Retrieved 3 November 2018 google open location code GitHub com Retrieved 3 November 2018 google open location code GitHub com Retrieved 3 November 2018 Delivering mail where the streets have no name Google Africa Blog December 1 2016 Plus Codes Addressing in Kolkata via YouTube The Navajo Nation is getting addresses thanks to an open source mapping program used in urban India The Salt Lake Tribune 2019 10 25 The Address of the Future Reasons to be Cheerful July 15 2022 google open location code GitHub Retrieved 3 November 2018 What s Wrong with Open Location Code QA Locate 2019 09 24 Retrieved 2022 11 07 Open Location Code An Open Source Standard for Addresses Independent of Building Numbers And Street Names GitHub 2019 04 21 Retrieved 2022 11 25 External links EditOfficial website with a video explanation open location code on GitHub Retrieved from https en wikipedia org w index php title Open Location Code amp oldid 1130865706, wikipedia, wiki, book, books, library,
