Passing data via URL on embedded form

If I use the hosted form from jotform, can I pass in URL data into a hidden field? If so is there a guide on how to do that?

If you mean on the embedded form, that's possible. It is the same way as prepopulating using the form URL. Guide http://www.jotform.com/help/71-Prepopulating-the-fields-to-your-JotForm-via-URL-parameters

You also need to embed your form using iframe to get it working.

Example:

http://mywebsite.com/embeddedform/?name=john&email=john@doe.com

If you need further assistance, let us know.