How accurate is Quandl's data?
Every single dataset on Quandl is guaranteed to be a perfectly accurate, up-to-date copy of the original data as published by the original source. We include links to all our sources so that you can always validate the accuracy and freshness of the data for yourself.
Our premium databases come from vendors who have decades of domain expertise creating highly accurate, reliable, professional grade data for sale.
Our free databases come from a variety of credible and established sources: central banks, multinational organizations, exchanges, government agencies and so on.
Both premium and free databases are extremely trustworthy.