The front squat is a more specific leg and trunk strength exercise to support the clean and jerk by emphasizing maximally upright posture, trunk rigidity and quad strength.
 
Place the bar in the clean rack position—keep the upper back extended while pushing the shoulders forward. Place the bar in the channel between the throat and the highest points of the shoulders. Keep the hands wrapped around the bar as much as you can while keeping the elbows raised high and the bar securely supported on the trunk, but the grip loose.
 
Place the heels at approximately hip width or slightly wider and turn the toes out 15-30 degrees from the center line.
 
Pressurize and brace the trunk forcefully with the lower back in its neutral curvature and the upper back flattened as much as possible.
 
Bend at the knees and hips together to squat as directly down as possible, maintaining even balance over the whole foot.
 
Keep the knees approximately in line with the feet.
 
Full depth is the knee joint closed as much as possible while maintaining whole foot balance and a neutral spine. If you don’t yet  have the mobility to squat to full depth, squat as deep as you can while maintaining proper back position and balance.
 
Maintain tension throughout the legs and trunk all the way through the bottom, and accelerate back up while maintaining an upright posture and whole foot balance.
 
Release a small amount of air as you stand without compromising trunk rigidity if you need to avoid dizziness.
 
Generally the front squat can be performed with a bounce in the bottom to replicate the clean, but at least some front squat training should be done with control through the deepest range of motion, including pauses.
 
Purpose
The front squat is a leg strength exercise very specific to the clean, but also will help the jerk by emphasizing quad strength, and improve the ability of lifters to pull from the floor with upright posture. It is also an effective trunk strengthening exercise, which further supports both the receipt and recovery of the clean and the dip and drive of the jerk. It is nearly always used in combination with the back squat for weightlifting.
 
Programming
There are a huge number of possibilities when it comes to programming the front squat. Most commonly weightlifters will use sets of 1-5 reps, but up to 10 reps are used in some cases early in preparatory phases of training and/or while gaining weight, although nearly always reps will remain lower than in the back squat for a given lifter and training phase. Generally squats are performed near the end of a training session after all competition lift variations and any other speed or technique-oriented exercises. However, they can be performed first in a session if leg strength is severely lacking and needs to be emphasized, or as a way to force an athlete to be more aggressive in subsequent competition lifts and at least theoretically force the body to recruit more and higher-threshold motor units. They can also be done as heavy singles prior to other lifts for the sake of post-activation potentiation, although the effectiveness of this is far from reliable.
 
Variations
The front squat can be performed with a pause in the bottom and/or during the eccentric or concentric phases, with slow eccentrics (usually 3-6 seconds), to partial depths, from pins or blocks at various depths, with accommodating resistance, with different stances, and with or without weightlifting shoes, among other options.
 
See More
Find Your Squat Stance
Squat Depth & Variation
Squat with Hips & Knees Together
Dial in Your Squat
Rack Position
Squat Position
Breathing & Bracing
Avoid Dizziness