Learn harai-goshi, the judo sweeping hip throw: turn-in, sweeping leg and pull. Honest and safe, with breakfalls, head position and a supervised partner.
The honest answer: harai-goshi is a hip throw with a sweeping leg in which you do not lift Uke but sweep his thigh away while his hip tips over your hip. The German Judo Federation lists harai-goshi in the basic programme, assigns it to 5th kyu and requires it at 4th kyu as a mandatory technique next to o-soto-gari and uchi-mata [1]. It is thus one of the throws every kyu candidate must show at some point.
It is a power throw: a 3D analysis classifies harai-goshi and o-soto-gari as "power throws" that transfer large impulse to Uke and suit strong, larger judoka [3]. That does not make it impossible for other body types, but it explains why timing and kuzushi matter more here than muscle strength. Expect several months until the chain of turn-in, sweeping leg and pull works in randori. That is a practical rule of thumb, not a study.
One hand on the sleeve, the other on the lapel. Upright, knees slightly bent, eyes forward. Milestone: you lead Uke forward and sideways without yanking.
You pull Uke sideways forward in the direction of your pulling hand. In a case study with one black-belt thrower, shifting Uke's centre of mass towards the pulling hand proved an ideal preparation for the turn-in [4]. Milestone: Uke rises onto his toes and shifts weight toward the pulling hand.
You turn in, bring your hip in front of Uke's hip and bend slightly forward. The hip turns first, then the shoulders follow: measurements showed a counterclockwise hip rotation at entry, then a clockwise shoulder rotation when completing the throw [4]. Milestone: you hold the turn-in position for one second without tipping over.
The leg sweeps horizontally backward and upward against Uke's thigh. In a kinetic study the sweeping velocity was directly linked to the ground reaction force of the standing leg: whoever pushes off stably and strongly sweeps faster [5]. Novices and advanced judoka differed clearly in horizontal force [5]. Milestone: in uchi-komi your sweeping leg meets Uke's thigh without you losing balance.
With your coach's approval you throw for the first time with reduced swing. The pulling hand draws Uke in an arc around the hip and accompanies him to the landing. In competition an ippon requires speed, force, landing on the back and controlled landing [2]. Milestone: Uke lands under control, you remain upright.
Several risks interlock here. First the head: harai-goshi is among the throws for which diving with the head first counts as dangerous and is punished with hansoku-make [2]. Second the back and joints: being thrown is the most common injury mechanism in judo [7]. Third the force: harai-goshi transfers a lot of impulse to Uke [3]. So, even stricter than with beginner throws: you only throw partners who can do ukemi securely, on tatami and under supervision, and at the start with reduced swing. And as Uke: never deliberately go into a bridge when being thrown, that is with head and feet on the mat. The rules score a voluntary bridge as ippon for tori precisely because it endangers the cervical spine [2]. This guide explains and motivates, it does not replace supervised training.
Ask your coach whether you should use harai-goshi as a combination throw. The throw is hard and straight; many use it after a feint or after a foot attack. Measurements under competition conditions showed that Uke's defensive movements shift the timing and size of the peaks in the throwing sequence [4]. Meaning: a throw in randori feels different from one in uchi-komi. Whoever only throws in uchi-komi knows only half of the throw.
It is a throw for the more advanced in the basic programme: the German Judo Federation assigns it to 5th kyu and requires it at 4th kyu [1]. As a beginner you are better off starting with o-goshi, where you set hip and back safely.
In harai-goshi your leg sweeps the thigh away from the outside, the hip serving as the pivot. In uchi-mata your leg snaps between Uke's legs and meets the inner thigh. The DJB counts both among the mandatory techniques on the kyu path [1].
In a study with ten judoka, participants managed more repetitions in the same time in o-uchi-gari than in harai-goshi and seoi-nage; the energy per repetition in o-uchi-gari was lower than in seoi-nage [6]. How many repetitions your coach asks for is individual.
That is individual. Expect months. That is a practical rule of thumb, not a study.
Uchi-mata: The Inner Thigh Throw That Demands Timing, Hip and Standing Leg