The dynamics of the detailed micromagnetic structure of domain walls in thin films are computed by numerical integration of the Landau‐Lifshitz‐Gilbert equation. The temporal and spatial variations of wall structure under a suddenly applied in‐plane field lying in the plane of the wall are investigated. The structure is substantially changed at in‐plane field strengths of only 2% of the anisotropy field,Hk. A critical in‐plane field value is reached at about 2.25% ofHk; at this point, the time required for the wall structure to reach equilibrium is a maximum. This settling time is also a function of the damping parameter &agr;. For &agr;≳0.1, the settling time is found to be nearly proportional to &agr;; for &agr;≲0.1, the settling time becomes larger as &agr; decreases due to oscillations of the wall structure. In the language of harmonic oscillators, the micromagnetic structure appears underdamped for &agr;<0.1, critically damped at &agr;?0.1, and overdamped for &agr;≳0.1.