Ancestry.com announced the complete indexing of the 1940 U.S. Census and I thought it would be a good idea to check in with all of the other sites and see what they say. Indexing the Census is a big deal or it isn't depending on your view of indexes in general. I have had spotty experiences using indexes of all kinds, not just Ancestry.com, but all online indexes for genealogy. I find that you cannot assume, merely because your search is negative, that the information you are seeking is not in the Census (or any other database for that matter). Having multiple indexes, separately compiled, of the same database is valuable, because the record may have been correctly or more accurately indexed by other indexers.
It remains to be seen which of the online sources will have the best "index" or whatever, but right now, the main race is over, almost all of the sites have their indexes well in hand and close to completion. It is important to remember that all of the images have been online for some time now on all of the major sites and you can always do your own search in the images without an index.
FamilySearch.org is moving right along in indexing the entire 1940 U.S. Census. The entire 1940 U.S. Census has been indexed but it is still in the process of being put online for searching. The process of completing the Census was more involved in the case of FamilySearch.org because each entry was indexed by two separate individuals and then the two entries were arbitrated by a third person. This seems to be an inherently more accurate index.
Archives.com has all of the images but the site says that the indexing is still in progress. Archives.com was part of the group of websites promoting the FamilySearch.org indexing effort. However, after the indexing was in progress reports were that Archives.com had been purchased by Ancestry.com. The future of this website is cloudy and we will have to wait and see how this all works out.
CensusRecords.com has a copy of the 1940 U.S. Census, but it isn't clear concerning the status. The website invites users to search the entire Census but does not include a listing for the 1940 U.S. Census in its search list.
MyHeritage.com also has a complete copy of the 1940 U.S. Census but says that they are still in the process of doing the indexing. Even though this is a subscription site, searching the 1940 U.S. Census is free.
Of course, the National Archives has copies of the U.S. Census records, but there is no mention of an index.
You may also want to check the following sites for information about the Census: