Overview
This page lists steps you can take and example of how to format the forward geocoding query you send to the OpenCage geocoding API. By following these guidelines you give us the best possible chance of answering your request correctly. Your query is the value you specify for the parameterq,
one of the two
required parameters,
on every request you make to the OpenCage geocoding API.
Please see the
API reference
for information on the various optional parameters.
Step by step guide to formatting your geocoding query
-
DO make sure your query is long enough
The query must be at least two characters long, we can not provide a meaniningful answer for a single character query.
Not Good:
BBetter:
Berlin -
DO separate the parts of the location with a comma and a space.
Not Good:
Trierer Straße 15 99423 Weimar DeutschlandNot Good:
Trierer Straße 15,99423,Weimar,DeutschlandBetter:
Trierer Straße 15, 99423, Weimar, Deutschland -
Send us only places/addresses
This might sound obvious, but we often see people geocoding lists of addresses - including the name of the resident or complex company names. That just confuses things.
Not Good:
Mr. Jack London, Trierer Straße 15, 99423, Weimar, GermanyBetter:
Trierer Straße 15, 99423, Weimar, GermanyThis is the most common mistake we see with forward geocoding. Leave out everything that is not part of the address.
-
DO NOT send us "intersections"
Sometimes people want to send us intersections, this is not a format we support.
Not Good:
Corner of 4th and Main St, Some TownBetter:
27 Main Street, Some Town, Country -
DO tell us which country you mean
-
Include the country name (in English or the local language) in the query
Not Good:
Trierer Straße 15, 99423, WeimarBetter:
Trierer Straße 15, 99423, Weimar, Deutschland -
DO NOT just append the ISO countrycode to the query
Not Good:
Trierer Straße 15, 99423, Weimar, DEBetter:
Trierer Straße 15, 99423, Weimar, GermanyISO codes in free text can be ambigious. Does
CAmean Canada or California? DoesDEmean Germany or Deleware? -
Use the optional
countrycodeparameterBetter:
&countrycode=deLearn more about the optional countrycode parameter.
-
-
DO remove unneeded formatting or abbreviations
Not Good:
Trierer Straße 15\n99423 Weimar\nBetter:
Trierer Straße 15, 99423, Weimar, DeutschlandRemove things like
c/o(common abbreviation for 'care of'), orPO BOXthat do not actually specify the location. -
DO remove unneeded address information
An extension of the rule above. Each additional word increases the chance of confusing things, so if possible remove unhelpful address information like "Floor" or "Suite" or "Apt" that don't help with determining the location.
Not Good:
720 VETERANS BLVD; STE 100, City, CountryBetter:
720 VETERANS Boulevard, City, Country -
DO NOT send us undefined values
We often see people send us queries that include
undefinedorNaNorMISSINGor just empty fields.Not Good:
undefined,Pueblo,CO,81003Not Good:
,,,CO,81003Not Good:
none,none,none,CO,81003Not Good:
-,-,-,CO,81003Not Good:
NULL,NULL,NULL,CO,81003Better:
Pueblo, CO, 81003, USA -
DO NOT send us placeholders
There is no need to send us things like XXXX for unknown postcode digits.
Not Good:
Augartenstrasse 26-28, Wien, xxxx, ÖsterreichBetter:
Augartenstrasse 26-28, Wien, Österreich -
9. DO treat postal codes as strings, not numbers
We often see queries with four digit postal codes when they should be five because the leading 0 has been removed somewhere along the way it was treated as a number rather than a string. If you know postal codes should be five digits add a check to ensure you are only sending us five digit strings.
Not Good:
77 Massachusetts Ave, Cambridge, MA 2142, USABetter:
77 Massachusetts Ave, Cambridge, MA 02142, USA -
DO NOT send us non-geographic addresses
Many countries have postal identifiers (postcodes, state codes) that represent non-geographic addresses. As an example, the US postal service has the states codes
AA, AE, APfor American military postal addresses. These do not correspond to any fixed location and thus can not be geocoded, though they are entirely valid addresses. It's better to not even send them to us.Not Good:
APO AE 09180, USA -
DO NOT send us things like URLs or code
Occasionally people intentionally or unintentionally try to "help us" by sending us software code or URLs in their queries. When we see this we will reject your request with response code
400 - missing or bad query.Not Good:
javascript:alert();some addressBetter:
an actual address or placename -
DO NOT send us overly long queries.
If your query is too long or contains too many logical units we will reject your request with response code
400 - query too long.Not Good:
some very very very very very very very very very very very very long long long long long long long long long addressBetter:
some normal address -
DO URL encode the query
Once you've done everything else, please make sure you URL encode the query. Most programming langauges have a standard library for URL encoding (sometimes also known as "percent encoding". Please use it, don't try to invent your own.
Not Good:
KölnBetter:
K%C3%B6lnNot Good:
Thành phố Hà NộiBetter:
Th%C3%A0nh%20ph%E1%BB%91%20H%C3%A0%20N%E1%BB%99i -
DO NOT double URL encode the query
Occasionally we've seen people encode the query themselves, and then the library they are using encodes the request again.
Not Good:
K%25C3%25B6lnGood:
K%C3%B6lnPlease make sure you understand what the libraries you are using do. If you run into problems a good first step is to print the actual HTTP request URL you are sending to us. Is it what you expected?
-
DO NOT assume we support "fuzzy matching"
Our geocoding API does not support "fuzzy matching". You can use our Geosearch service for that.
Not Good:
parGood:
paris
Final thoughts
You might ask why you need to bother doing all this, surely we should catch common problems on our side? A fair question. We do try to catch obvious things, of course.
As you can imagine though, it's difficult for us know all the pecularities of your data in your language and country. The more you can do to simplify, clean, and correct your queries, the better a chance we have to geocode quickly and correctly.