Today you can not only purchase a will online and download a form to fill out, you can even find websites that will let you create a free will and sign it digitally. You should not use these services.
There is stiff competition for cheap online wills or you can fill one out for free here, http://www.calbar.ca.gov/Portals/0/documents/publications/2014_CAStatutoryWillForm_ab_1986_bill_20100715.pdf
They regularly pop up and try to beat each other in search engine rankings.
One new trend is for sites to have wills that are completely digital. You can answer some questions to have the will made.
You then sign the will digitally and think you have a will, as Jewish Link of New Jersey discusses in "Why You Really Don't Want an Online Will."
If you use one these sites, you really do not have a will.
You have nothing at all but lost time.
In order to be valid in court, wills must be executed in specific ways.
That means you need to sign the will in front of witnesses, who also need to sign the will.
In some states, a notary public must also be present to certify that you and the witnesses signed the will.
If these steps are not taken, then the will cannot be entered into probate court.
Online wills are not worth your time.
Even if they do not make the basic error above, you cannot trust them to not make other mistakes.
Wills need to be carefully crafted legal documents. You should see an estate planning attorney to get one.
Reference: Jewish Link of New Jersey (August 24, 2017) "Why You Really Don't Want an Online Will."