MaxMind tests the accuracy of the GeoIP Databases on a periodic basis. The following table shows a breakdown of recent test results for the accuracy of GeoIP City on a city level by country for selected countries. The GeoIP databases tested at 99.8% accurate at a country level. We arrive at the accuracy figure by checking known IP address and location pairs against our database. We obtain the known IP location pairs from sites that ask the web visitor to provide their geographic location. The geographic location along with the web visitor's IP Address is forwarded to us.

Generally speaking, we are more accurate for broadband IP addresses and less accurate for mobile/cellular networks. Not being able to determine the location of cellular networks is a general limitation of IP geolocation services, due to the wide area cell phone companies allocate IPs over.

While only larger countries are shown below, the GeoIP City database covers cities worldwide.

It is suggested that clients stay as up to date as possible with the databases, as their accuracy erodes over time as IP addresses shift location. As a database gets more and more out of date, it loses accuracy at a rate of approximately 1.5% per month. So, for example, our current GeoIP City database tested as 83% accurate for the US, but last month's release tested (for current data) only 81.5% accurate, and a six-month old version tested only 74% accurate. These databases can still be useful for testing historic data, since they tested as 83% accurate at the time they were first released, but for current use, the most recent database is suggested.

Disclaimer: Due to the nature of geolocation technology and other factors beyond our control, we cannot guarantee any specific future accuracy level. Nevertheless, we expect that the GeoIP City database will at any given time in the future correctly identify locations with an accuracy meeting the level of accuracy indicated in the table below.

Table Terms:

Correctly Resolved Within 25 Miles of True Location: refers to the IP addresses that are correctly resolved within 25 miles of the actual city. The second number in parenthesis refers to the percentage of IP addresses that are correctly resolved if excluding data not covered on a city level.

Incorrectly Resolved More Than 25 Miles From True Location: refers to IP addresses that were incorrectly resolved by more than 25 miles of the actual city.

Not Covered on a City Level: refers to the percentage of the data of select country that does not contain city information. We leave these data ranges without city information to prevent false positives. The city information is not available for AOL IP address or when Internet Service Providers (ISPs) route traffic through proxies thus masking the originating location.

Updated April 20th, 2012

Countries	Correctly Resolved Within 25 Miles of True Location	Incorrectly Resolved More Than 25 Miles from True Location	Not Covered on a City Level
Argentina	75% (77%)	23%	2%
Australia	58% (67%)	28%	14%
Austria	73% (80%)	18%	9%
Belgium	84% (87%)	13%	3%
Brazil	72% (76%)	23%	5%
Bulgaria	75% (81%)	18%	7%
Canada	82% (83%)	17%	1%
Chile	84% (86%)	13%	3%
China	75% (78%)	21%	4%
Cote D'Ivoire	96% (97%)	3%	1%
Croatia	72% (74%)	25%	3%
Cyprus	80% (86%)	13%	7%
Czech Republic	82% (85%)	14%	4%
Denmark	84% (89%)	11%	5%
Finland	66% (73%)	24%	10%
France	67% (72%)	26%	7%
Germany	78% (82%)	18%	4%
Greece	69% (70%)	29%	2%
Hong Kong	90% (91%)	8%	2%
Hungary	70% (77%)	22%	8%
Iceland	83% (84%)	16%	1%
India	61% (63%)	36%	3%
Indonesia	55% (61%)	35%	10%
Ireland	51% (71%)	21%	28%
Israel	72% (77%)	22%	6%
Italy	63% (69%)	29%	8%
Japan	81% (82%)	17%	2%
Korea, Republic of	77% (88%)	10%	13%
Latvia	78% (81%)	18%	4%
Luxembourg	87% (93%)	8%	5%
Malaysia	68% (70%)	29%	3%
Mexico	78% (78%)	21%	1%
Netherlands	85% (89%)	11%	4%
New Zealand	68% (70%)	29%	3%
Norway	78% (81%)	18%	4%
Pakistan	67% (73%)	24%	9%
Peru	90% (91%)	9%	1%
Philippines	50% (61%)	32%	18%
Poland	58% (62%)	36%	6%
Portugal	74% (79%)	21%	5%
Romania	69% (74%)	24%	7%
Russian Federation	82% (83%)	16%	2%
Saudi Arabia	57% (63%)	33%	10%
Singapore	93% (96%)	4%	3%
Slovakia	45% (65%)	25%	30%
South Africa	71% (72%)	26%	3%
Spain	72% (75%)	24%	4%
Sweden	72% (73%)	27%	1%
Switzerland	73% (83%)	15%	12%
Thailand	59% (83%)	13%	28%
Turkey	64% (65%)	35%	1%
Ukraine	56% (70%)	24%	20%
United Arab Emirates	76% (85%)	14%	10%
United Kingdom	72% (77%)	21%	7%
United States	81% (85%)	15%	4%