<p>The solar chromosphere plays an important role in the transport of energy between the cool, dense photosphere and hot, tenuous corona. The determination of the thermodynamic and kinematics conditions of the chromosphere is crucial to understand the above coupling which is often done with the help of spectral inversion codes (ICs). We study and describe the performance of two ICs that are fundamentally unique in principle, implementation, and speed to infer the temperature of the solar chromosphere over a 3 arcmin field-of-view. We obtained spectral line scans of NOAA active region (AR) 12765 with the Ca <span>ii</span> 8542 Å line using the narrow-band imaging spectro-polarimeter on the 50-cm Multi-Application Solar Telescope at the Udaipur Solar Observatory, India. The temperature of the lower to mid-chromosphere was inferred from the following two ICs, namely, i) Non-LTE Inversion COde using the Lorien Engine (NICOLE) and ii) CAlcium Inversion based on a Spectral ARchive (CAISAR). A similar fit quality of the spectra is obtained with the resulting temperature stratification in good agreement with one another for a significantly large part of the field-of-view, despite the intrinsic differences in the two ICs. A few locations at the umbra-penumbra boundary and palge regions show a deviation in the two temperature stratifications which, to a first order, can be attributed to the generation of the archive spectra in CAISAR, where localised, Gaussian enhancements are provided to the temperature profile and the line-of-sight velocity is not considered/ignored. Once the spectral archive is created, CAISAR is several orders of magnitude faster than the conventional IC NICOLE, can be executed on a simple off-the-shelf workstation, and provide 3-dimensional temperature cubes with temporal information, that is ideally suited for processing observations from imaging spectrometers at most modern solar facilities.</p>