Abstract This research scrutinizes the impact of external magnetic field strength variations on plasma jet parameters to enhance its performance and flexibility. Plasma jets are widely used for their high thermal and kinetic energy in both medical and industrial fields. The study employs optical emission spectroscopy to measure electron temperature, electron density, and plasma frequency in a plasma jet subjected to varying magnetic field strengths (25, 50, 100, 150, and 250 mT). The results indicate that a stronger magnetic field results in higher electron temperature (1.485 to 1.991 eV), electron density (5.405 × 1017 to 7.095 × 1017), and plasma frequency 7.382 × 1012 to 8.253 × 1012 Hz. As well as the research investigates the influence of gas flow rate on gas temperature in the plasma jet. It is observed that gas temperature gradually drops with a growth in the flow rate of argon gas. The voltage and current waves have a sinusoidal waveform without elevation lines and with decaying waveforms. The existence of a strong magnetic field generates magnetohydrodynamic instability, leading to the plasma jet flame splitting. Understanding the effects of changing the strength of the external magnetic field on the plasma properties provides the ability to control the plasma Permart to make it suitable for many applications.