How can I tell from which source each lead is coming from?

My urls have analytics parameters on them. I would like to pull that data into each lead that is recieved. How can i do this?

Are you referring to the submission data? You can find each data in the submissions page. Here's how:

1. In the My Forms page, select the form and click the Submissions button.

2. You can find individual data on this page. 

You can also check these widgets: 

1. Get Referrer widget - This widget reports all the URL's which referred visitors to your form.

2. Get Form Page URL widget - This widget detects the webpage where you embedded the form and provides the page URL each time the form is submitted.

Hope that helps. If I misunderstood your concern or you have further questions, please contact us again. Thank you.