Eight Limbs vs. Four
Muay Thai is called the art of eight limbs: punches, kicks, knees and elbows. Most kickboxing rule sets allow only punches and kicks, and some limit knees.
The Clinch
The biggest difference. In Muay Thai, fighters grab the neck and body to control each other and land knees. Kickboxing referees usually break the clinch quickly, so it is barely trained.
Rhythm and Stance
Muay Thai stances are taller and more upright to check kicks and fight in the clinch. Kickboxing tends to be lower, bouncier and faster-paced with more punching volume.
Which Should You Train?
If you want a complete striking system with deep tradition, train Muay Thai. Everything you learn in kickboxing exists in Muay Thai, plus elbows, knees and the clinch. Add Brazilian Jiu-Jitsu and you have both striking and grappling covered.