I need to geocode around 200 addresses per request and do around 3,000 request per day. I will be doing this server side using PHP. I have looked at How to convert an address to a latitude/longitude?, but could not find a way for either Google Maps HTTP Request API or the Yahoo Geocoding REST API (cannot use JavaScript as this is server side) to send multiple addresses.
I will be primarily using this to sort addresses based on the coordinates and if the API supports, fill in any missing data for each address. The addresses will be in the United States only. The addresses to geocode will be from user input, so be free form, like "street address, postal code", or "city, state", etc. Accuracy is not too important for the coordinates, say within five hundred feet or so.
Is there a free API to handle this? Is there a way to get Yahoo or Google to do multiple locations in a request?
geocoder.us will do what you want, but you may have the same problem for bulk lookups. They do bulk lookups for a fee though.
Would GeoNames provide sufficient information, either through the bulk raw data or via their web services?
I've looked at the Google Maps api, Yahoo Maps Api, MapQuest API, and the Microsoft Virtual Earth API. None of these free services allow bulk geocoding.
But, Google Maps api allows 15,000 goecodes per day. But they don't like it when you send too many at one time. They suggest waiting 200ms between requests. They track you by IP address btw.
Yahoo allows 5,000 per day, and is also an easy api to use. Microsoft Virtual Earth allows 5,000 per day, but the api documentation is a pain in the butt.
MapQuest is just strange, and doesn't seem to give good results (least accurate of all that I've seen).
I've actually set up my code to alternate between several services so I can make multiple requests at once. This - sort of - simulates bulk encoding.
The USC WebGIS Geocoder offers several geocoding API's that can do this. It's free and allows batch lookups from your code, or you can upload a database for batch processing.
Mapquest has an API which allows batch geocoding. However they don't provide one directly for PHP. But you can look up their protocol documentation http://developer.mapquest.com/Library/SDK_Documentation/Protocols to implement it yourself. They may refer to bulk geocoding as a Location Collection in the docs.
This might sound odd but I did a site a while ago and the client wanted the user to enter only a zip and we would provide the remaining data. I used the yahoo weather api which, at the time, returned a xml file with all the weather data, and the ciy,state,zip worked well for addresses in the US
Look at http://www.torchproducts.com/tools/geocode to geocode a list of addresses quickly
Use GDirections. It allows up to 25 waypoints at a time and returns a geocoded location for each one.
来源：https://stackoverflow.com/questions/396819/geocode-multiple-addresses