Language Services

Natural Language Processing Centre provides several APIs for different language services.

How to use the API

You can call the API via GET requests. See examples in the service description.


Required parameters: call=service name, text=text

Optional parameters: output=output (text/JSON applicable only for some services), lang=language (applicable only for some services)

Service-specific parameters: see service description


If output is set to json, returns always a JSON object. See example calls to check the object structure. If output set to text, outputs a text. The default format is text for most services.

Rate limits

You can call the API once a second maximum from one IP address.

The daily limit is set to 500 calls.

Available languages

Available services


All services are provided under the NLP Centre Web Service Licence.

How to add a service

  1. Find a unique name <service_name> for the call.
  2. Create <service_name.json> with the description in the languageservices/json directory. See hello.json as an example.
  3. Add limit to text length (number of characters).
  4. Test it.