A number of reputable sites all give this information:-
The Official ESTA Website
Many other websites are operating under the claims that they are the official ESTA website, which is not true. There is only one official ESTA website, and that is:
https://esta.cbp.dhs.gov
Every other website, whether it ends with .
com, .org, .us, .esta, or any other, is not official, and does not operate on behalf of the United States government. Remember that all of the US official websites end with
.gov.
The official ESTA charges the applicants with a fee of $14.00, which includes a fee of $10.00, collected pursuant to the Travel Promotion Act (TPA), and a fee of $4.00 for administering ESTA.