This research evaluates the effects of applying different kinetic models (KMs), developed based on thermal analysis using thermogravimetric analysis data, when used in typical 1D pyrolysis models of fiberglass-reinforced polymer (FRP) composites. The effect of different KMs is isolated from the FRP heating by conducting pyrolysis modeling based on measured temperature gradients. Mass loss rate simulations from this pyrolysis modeling with various KMs show changes in the simulations due to applying different KM approaches are minimal in general. Pyrolysis simulations with the most complex KM are conducted at several heat flux levels. Mass loss rate comparison shows there is good overlap between simulations and the experimental data at low incident heat fluxes. Comparison shows there is poor overlap at high incident heat fluxes. These results indicate that increasing complexity of KMs to be used in pyrolysis modeling is unnecessary for these FRP samples and that the basic assumption of considering thermal decomposition of each computational cell in comprehensive pyrolysis modeling as equivalent to that in a thermogravimetric analysis experiment becomes inapplicable at depth and higher heating rates. Copyright © 2014 John Wiley & Sons, Ltd.