Is a fountain soda less carbonated then can soda?

Fountain soda and can soda typically have similar levels of carbonation.

The carbonation level in soda is determined by the amount of carbon dioxide gas dissolved in the liquid. When soda is dispensed from a fountain, the carbon dioxide gas is injected into the water and syrup mixture under pressure, creating bubbles. Similarly, when soda is canned, carbon dioxide gas is added during the filling process.

Therefore, both fountain and can sodas generally contain the same amount of carbonation, unless specifically noted by the manufacturer.