  We demonstrate a Bell state analyzer that operates directly on frequency
mismatch. Based on electro-optic modulators and Fourier-transform pulse
shapers, our quantum frequency processor design implements interleaved Hadamard
gates in discrete frequency modes. Experimental tests on entangled-photon
inputs reveal accuracies of $\sim$98\% for discriminating between the
$|\Psi^+\rangle$ and $|\Psi^-\rangle$ frequency-bin Bell states. Our approach
resolves the tension between wavelength-multiplexed state transport and
high-fidelity Bell state measurements, which typically require spectral
indistinguishability.
