English: A comparison between high-field and zero-field NMR spectra of a sample containing a mixture of [2-¹³C]-acetic acid and [2-¹³C]-bromoacetic acid. In the high field, the ¹H and ¹³C nuclear spins species precess at different frequencies, yielding distinct ¹H and ¹³C spectra with the J-coupling perturbation splitting the resonance into doublet, triplet or quartet multiplet patterns. At zero field, there is no Larmor precession and the resonance frequencies are determined principally by the J-couplings. Another notable feature is the narrow line width at zero field, owing to a lack of inhomogeneous broadening.