  We show how the output of the algorithm to compute modular Galois
representations described in our previous article can be certified. We have
used this process to compute certified tables of such Galois representations
obtained thanks to an improved version of this algorithm, including
representations modulo primes up to 31 and representations attached to a
newform with non-rational (but of course algebraic) coefficients, which had
never been done before. These computations take place in the Jacobian of
modular curves of genus up to 26. The resulting data are available on the
author's webpage,
http://www2.warwick.ac.uk/fac/sci/maths/people/staff/mascot/galreps.
