How can I trust Quandl's data?
Quandl's free data comes from established sources such as central banks, multinational organizations, government agencies, stock markets and commodity exchanges. Free data feeds on Quandl have links back to its original source. This lets you verify the data as published by its original source. Transparency is the ultimate enabler of trust.
Quandl's premium data is curated by specialist data providers who have decades of domain expertise creating professional-grade data for sale. Thanks to this expertise, premium data feeds are without exception more accurate, better documented, better structured and timelier than their free equivalents. We vouch for the quality, reliability and value of all premium data feeds on Quandl. You can see a list of our data providers on our Partners page. If you're interested in becoming a data partner and would like to learn more about selling your data on Quandl, please go to our Data Monetization page and take our short survey.