Plus Codes (Open Location Code)

Overview

The Plus Codes encoder and decoder converts between latitude/longitude coordinates and Open Location Codes - short alphanumeric codes that work like postal codes for any spot on Earth. Drop in a coordinate and the tool returns its Plus Code; paste in a code and it returns the centre coordinate plus the bounding box of the cell.

Plus Codes were designed by Google in 2014 to give every location on the planet a memorable address, including places without conventional street addresses. A full 10-character code such as 8FVC9G8F+6X identifies a 13.5 by 13.5 metre area. Shortened forms drop the leading characters when a nearby city is given as context, so 9G8F+6X Geneva resolves to the same spot as the full code. Emergency services, NGOs, mapping platforms and humanitarian agencies use Plus Codes wherever postal addressing is inconsistent.

How it works

A Plus Code is a base-20 grid encoding. The world is divided into a 9 by 18 grid of cells 20 degrees on a side, with characters drawn from a 20-letter alphabet (23456789CFGHJMPQRVWX - vowels and visually similar digits removed). The first two characters identify the cell, the next two narrow it to 1 degree, and so on. After eight characters a literal + is inserted - this distinguishes the code from anything else - and a final two characters refine to roughly 13.5 metres. Codes can extend to 11 characters for 2 m precision.

Shortened codes drop the first four characters and pair the remaining six with a place name (city, town or region). Recovery uses the place's coordinates to fill the missing prefix from the nearest matching full code.

Examples

• (46.2044, 6.1432) - Geneva - encodes to 8FR9C234+CR at 11 characters, about 2 m precision.
• (37.4220, -122.0841) - Googleplex - encodes to 849VCWC8+R9.
• 8FVC9G8F+6X decodes to centre roughly (47.36, 8.55) - Zurich.
• The shortened form 9G8F+6X Geneva resolves to the same Zurich-area cell only if the recovery hint is correct.

FAQ

How is Plus Code different from a geohash?
Both are hierarchical grid encodings. Geohash uses a base-32 alphabet inherited from Geohash.org and produces variable-length codes without a separator. Plus Codes use a 20-character alphabet, include a literal + separator, and were designed for human use - intended to be spoken, written and remembered.

Can I shorten a Plus Code?
Yes. The first four characters can be dropped when paired with a nearby place name. The shortened form needs the place to disambiguate, so a code without context must always be the full 10 or 11 characters.

Which alphabet does the code use?
Twenty characters: 2 3 4 5 6 7 8 9 C F G H J M P Q R V W X. Vowels are excluded to prevent words forming by accident, and visually ambiguous digits (0, 1) are omitted.

Is the standard open?
Yes. The Open Location Code specification is published under the Apache 2.0 licence and is implemented in many open-source libraries.

Try Plus Codes (Open Location Code)