web to case using API

Absolutely, it's possible to create cases from an external web form using Salesforce APIs. Here's a brief rundown:

1. SOAP API: Salesforce provides the SOAP API that allows you to create, retrieve, update or delete records, such as cases. You would need to create a web service on your end that calls the appropriate methods of this API.
2. REST API: Alternatively, you can use the Salesforce REST API which operates on the same principle, but with a simpler, HTTP-based protocol.

In both cases, you would capture the form data on your website, then send an API request to Salesforce with the captured data to create a new Case record. It's important to ensure your API calls are secure, and they are properly authenticated with Salesforce.
However, bear in mind that this requires programming knowledge to implement. If you are looking for a no-code solution, the standard Web-to-Case form might be a better fit.