The work consists of the sensitivity analysis of the modeling of losses in the polarization curve and the general efficiency in the operating conditions in the thermodynamic modeling applied to PEMFC (Proton Exchange Membrane Fuel Cell) and SOFC (Solid Oxide Fuel Cell) . To obtain the best modeling among the equations used in the literature, according to the technology and the power offered by the cell, verifying the sensitivity for the parameters used. Through literature correlations, identify the most suitable articles and validate with experimental data the modeling from a simulation developed with its equations. After the validations, by Trindade (2020), Sharaf (2014) and Azizi (2018), the parameters were varied in the simulation to analyze from the variation of the maximum power output value, voltage and current density for maximum power, which models are more sensitive to variations in the respective parameters. With the results for analysis, it was identified that for each of the potential, activation, ohmic and concentration losses, there is a parameter that sensitizes the model more. In the activation loss, the parameter with the greatest impact on the final result is the cathode charge exchange coefficient, which proved to be the parameter with the greatest maximum power variation. For the ohmic loss, it was the resistivity of the cell components, the greater the resistance of the components, the lower the output power. Finally, for the concentration loss, it is the threshold current density, as it impacts the charge transfer threshold through the cell. In relation to better modeling, when comparing the models of Trindade (2020) and Sharaf (2014), it was possible to identify that the models with a greater number of parameters dilute the sensitivity between them more, and when compared between Azizi s (2018) and the PEMFC models, the model with lower sensitivity still stands out for the same reason, showing a sensitivity to the cathode charge exchange coefficient, the component resistivities and the cell limit density, demanding more attention.