Get started here. Before you can use the text analyzer, you'll need to find a text to upload. Text files should be in .txt format. Project Gutenberg is a great place to find free texts in this format. Locate the plain text version of the text you want to analyze and download it to your machine.
If you want to get started quickly, here are a few files that you can download directly.
Once you have a text ready for upload, use the "choose file" button on the right side of this page and find the file on your machine. The upload may take several seconds, depending on the length of the text. Make sure to fill out the other fields to the best of your knowledge as well.
Then, just hit the submit button and see what the tool reveals.