The following table shows a breakdown of the accuracy of GeoIP City on a city level by country for selected countries. The GeoIP databases are over 99% 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.

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 As a database gets more and more out of date, it looses accuracy at a rate of approximately 1.5% per month. So, for example, our current GeoIP City database is 81% accurate for the US, but last month's release is (for current data) only 79.5% accurate, and a six-month old version is only 72% accurate. These databases can still be useful for testing historic data, since they were 81% accurate at the time they were first released, but for current use, the newest possible database is suggested.

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 February 12th, 2008

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	77% (77%)	22%	1%
Australia	66% (66%)	33%	1%
Austria	78% (78%)	21%	1%
Belgium	89% (90%)	10%	1%
Brazil	74% (76%)	23%	3%
Bulgaria	83% (85%)	14%	3%
Canada	83% (83%)	16%	1%
Chile	73% (74%)	25%	2%
China	60% (61%)	38%	2%
Colombia	82% (83%)	17%	1%
Croatia	78% (79%)	21%	1%
Cyprus	82% (82%)	17%	1%
Czech Republic	71% (71%)	28%	1%
Denmark	83% (84%)	16%	1%
Egypt	73% (79%)	20%	7%
Estonia	77% (77%)	22%	1%
Finland	84% (84%)	15%	1%
France	65% (66%)	33%	2%
Germany	75% (75%)	24%	1%
Greece	58% (58%)	41%	1%
Hong Kong	84% (86%)	14%	2%
Hungary	76% (76%)	23%	1%
Iceland	89% (89%)	10%	1%
India	67% (70%)	30%	3%
Indonesia	72% (73%)	26%	2%
Ireland	72% (73%)	27%	1%
Israel	72% (73%)	27%	1%
Italy	63% (63%)	36%	1%
Japan	72% (78%)	21%	7%
Korea, Republic of	61% (86%)	9%	30%
Latvia	87% (88%)	12%	1%
Luxembourg	95% (95%)	4%	1%
Malaysia	66% (68%)	31%	3%
Mexico	78% (79%)	21%	1%
Netherlands	87% (87%)	12%	1%
New Zealand	66% (69%)	30%	4%
Norway	78% (80%)	20%	2%
Philippines	71% (72%)	28%	1%
Poland	67% (68%)	32%	1%
Portugal	75% (75%)	24%	1%
Romania	64% (64%)	35%	1%
Russian Federation	85% (87%)	13%	2%
Saudi Arabia	44% (51%)	43%	13%
Singapore	94% (95%)	4%	2%
Slovakia	60% (61%)	39%	1%
Slovenia	79% (79%)	20%	1%
South Africa	72% (73%)	26%	2%
Spain	75% (76%)	24%	1%
Sweden	81% (81%)	18%	1%
Switzerland	62% (63%)	37%	1%
Taiwan	85% (87%)	14%	1%
Thailand	72% (73%)	27%	1%
Turkey	82% (82%)	17%	1%
United Arab Emirates	76% (78%)	21%	3%
United Kingdom	54% (64%)	31%	15%
United States	81% (83%)	16%	3%
Venezuela	69% (69%)	30%	1%