There are a number of sources available for company financials for publicly traded companies. Fewer sources are available for private companies, and when you do find figures, those are less likely to be exact figures, but are often estimates.
Use the "Get Company Info" search to find a company report. You'll find some financial information on the left side. If you select the Compare Companies link (at the bottom of the report), you can compare balance sheets, income statements, and ratios for up to 5 companies at a time.
All companies, foreign and domestic, are required to file registration statements, periodic reports, and other forms electronically through EDGAR. Anyone can access and download this information for free. On the left side of the page, select Company Filings Search.
If you're looking for information in the financial filings, it can be useful to select the link for SEC Forms List (PDF versions) and look at the form descriptions.
Other financial databases
Also see resources listed under the Company Research tab.
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