I have tried most of the major grant research data-bases. At this point, I do not have any strong preferences between them. They all seem to draw off the same government compiled IRS 990 statements. If the database can give you the top funders in your local area, then they are good enough for me and for most of us. Here is a quick review of your choices.
The Foundation Center
The Foundation Center is the best resource for almost anything related to funding by foundations. The “Foundation Finder” allows you to look up considerably basic information on foundations free of charge. You can also subscribe to The Foundation Directory Online. This comprehensive database provides foundation funding priorities and past grants. Several subscription levels give access to over 100,000 foundations, corporate donors, and public charities. The Foundation Directory is truly the gold standard for databases and is well worth a subscription.
Grants.Gov
If you want to apply for federal government grants, Grants.gov has to be your first stop. This U.S. government website has lots of useful information for nonprofits, including announcements of federal grants. Using the database is somewhat tricky.
Guidestar
Guidestar provides information on all kinds of nonprofits, including foundations. You can register for free and use the advanced search capabilities to find the 990-PFs of foundations.
The Grantsmanship Center
This site is a treasure of information about grants: getting them, finding resources, writing grant proposals. My favorite part of the site is the Funding State by State. There is a map of the U.S. where clicking on a state brings up links to top grantor foundations, community foundations, corporate giving programs, and the state website homepage.
Community Foundation Locator
The Community Foundation Locator is sponsored by the Council on Foundations. The website displays a map of the U.S. where you can click on your region to pull up a list of its local community foundations and links to those foundation sites.
The Chronicle of Philanthropy
The Chronicle is an excellent source of news on the foundation and nonprofit world, and there is a grants database. You do have to subscribe, however, to access the database. There are a limited number of articles available for free.
BIG Online
A for-profit resource, BIG Online provides online and telephone assistance for navigating the various tools on its website. It also offers online classes to learn more about the features of its extensive database, which contains the 990s of many funders. Do not underestimate how much useful information you can find just on these tax returns.
GrantStation
GrantStation allows grant seekers to identify potential funding sources for their programs or projects and mentors them through the process. The site maintains a searchable database of active requests for proposals, federal grant deadlines, online tutorials, and many webinars. You must join the site for full access although a few features are free.
Instrumentl
Instrumentl puts nonprofit grant search on autopilot. Nonprofits provide basic information about their programs and projects and Instrumentl matches them with relevant funding opportunities and helps to manage their process. A paid subscription promises to save dozens of hours and thousands of dollars that you might otherwise spend tracking down the best leads.