  This paper aims to put constraints on the transition redshift $z_t$, which
determines the onset of cosmic acceleration, in cosmological-model independent
frameworks. In order to do that, we use the non-parametric Gaussian Process
method with $H(z)$ and SNe Ia data. The deceleration parameter reconstruction
from $H(z)$ data yields $z_t=0.59^{+0.12}_{-0.11}$. The reconstruction from SNe
Ia data assumes spatial flatness and yields $z_t=0.683^{+0.11}_{-0.082}$. These
results were found with a Gaussian kernel and we show that they are consistent
with two other kernel choices.
