What Is an IJF-Approved Judogi: Uniform Rules and Requirements

An IJF-approved judogi is a competition uniform that meets the International Judo Federation’s published technical specifications and has been tested and certified by the IJF’s equipment division. Since April 1, 2015, wearing an IJF-approved judogi — identified by its official red label — is mandatory at all IJF World Tour events. An athlete arriving at weigh-in without a compliant gi is barred from competing. The specifications cover fabric weight, color, collar dimensions, sleeve length, jacket overlap, and logo placement, and they exist to ensure that all athletes compete with uniform gripping conditions — since the judogi is the primary tool for controlling and throwing opponents, its specifications directly affect competitive fairness.

What Is an IJF-Approved Judogi and Why Approval Matters

The judogi is not passive clothing — it is the central mechanical element of judo competition. Every throw, hold-down entry, and grip-fighting exchange depends on the jacket’s collar, sleeves, and lapels. A gi that is too stiff, too loose, too slippery, or with a collar too thick to grip properly changes the competitive dynamic in ways that give the wearer an unfair physical advantage. The IJF’s approval system addresses this by publishing precise specifications that all certified manufacturers must meet, then testing production samples against those specifications before issuing the approval label. The red label sewn into the collar of a compliant gi contains an optical code that officials scan at judogi control — a check that takes place at every IJF event before the athlete steps on the mat. An athlete whose gi fails inspection must replace it before competing. The system was tightened substantially in 2015, when the mandatory red-label requirement replaced an older, more loosely enforced approval framework. For fans watching a World Tour event, the judogi control checkpoint before competition is as routine as weigh-in: every athlete’s uniform is measured, checked, and logged.

Who Can Manufacture IJF-Approved Judogi

Only manufacturers that have submitted their gi for IJF testing and received approval may produce gis bearing the certification label. The IJF publishes a current Official Supplier List on its website listing approved brands. The major approved manufacturers include Adidas, Mizuno, KuSakura (the oldest continuously operating judo equipment company, founded by Hayakawa Juichi in Japan in 1918), Fighting Films, Matsuru, Daedo, Green Hill, Essimo, and others. Each manufacturer’s approved models have specific label codes — not all gis from a given brand are certified; only the models submitted and tested. This means a judoka buying competition gear must check the specific model and label rather than assuming any gi from an approved brand is competition-legal. The IJF updates its approved list periodically, and gis approved under older standards may lose current-competition eligibility after rule revisions.

Technical Specifications: Fabric, Color, and Fit Requirements

The IJF publishes detailed judogi specifications covering every measurable dimension of the uniform. The core requirements for competition-legal judogi are:

Fabric: Weight must be between 650 and 750 g/m². Cotton content must be 70% or more; synthetic fibers may comprise the remaining 30% maximum. The fabric must meet durability standards that prevent tearing during competitive gripping and throwing.

Collar: Width must be exactly 4 cm, sewn with a minimum of 4 rows of stitching. Collar thickness may not exceed 1 cm (except at sewn seams in specific locations). A collar that is too thick is one of the most common judogi rejection reasons — a wider collar is harder to grip, creating an unfair defensive advantage for the wearer.

Sleeves: Must reach the base of the wrist (the head of the ulna), with a maximum tolerance of 1 cm. The space between the arm and the interior of the sleeve must be between 10 and 15 cm — this specification prevents overly tight sleeves that reduce gripping surface and overly loose sleeves that provide uncontrollable fabric excess.

Jacket length and overlap: The jacket skirt must cover the buttocks with a 5–10 cm overhang. The lapels must cross at a minimum of 25 cm at belt level. The vertical distance from the sternum top to the lapel crossing point must be less than 10 cm — this controls how deeply the jacket opens, which affects lapel-grip accessibility.

Color: White judogi must be perfectly white or off-white (unbleached natural). Blue judogi must match the IJF-specified Pantone color range — between 18-4051TCX and 18-4039TCX — the specific shade of blue used at all World Tour events. Colors outside this range are non-compliant. The blue judogi was introduced to allow officials, broadcasters, and spectators to distinguish athletes instantly during competition; at most IJF events, one athlete wears white and one wears blue, with designation determined by seeding or draw position.

Markings and logos: Only one manufacturer’s logo is permitted per item (jacket, trousers, and belt separately). Logo area on the jacket and trousers may not exceed 30 cm²; on the belt, the maximum is 9 cm². National federation flags and athlete name patches may be added within additional specification limits. Female athletes must also wear a white round-neck T-shirt underneath the jacket for all IJF competition.

Judogi Control: How Uniform Checks Work at Events

At every IJF World Tour event, athletes pass through a judogi control station before competing. Officials use standardized measurement tools — a collar thickness gauge, a sleeve-space template, and a scanning device for the label’s optical code — to verify compliance. Athletes who fail are given a short window to change into a compliant gi; if no compliant gi is available, they are withdrawn from competition. The IJF’s judogi control process is separate from the weigh-in but equally non-negotiable. At major events like Grand Slams and World Championships, athletes typically bring multiple approved gis to avoid disqualification from a single equipment issue. The grip-fighting dimension of elite judo makes the uniform specification a genuinely competitive matter — athletes and coaches invest in specific gi models not just for compliance but because collar and sleeve properties within the allowed range affect how grips feel and function in match conditions.

History and Design of the Judogi: From Kano to Modern Standards

Jigoro Kano designed the first judogi between 1882 and 1889 at the Kodokan in Tokyo, deriving it from the Japanese kimono and other traditional garments. The design challenge was specific: Kano needed a garment strong enough to withstand repeated grip-and-throw training without tearing, loose enough to allow freedom of movement for large hip and shoulder throws, and simple enough to be practical for daily practice. Early judo training had used modified kimonos, which tore regularly and restricted movement — Kano tested multiple fabric weights and constructions before settling on the design his first generation of students adopted. By 1906, the judogi had reached its classic form with long sleeves and the cut we recognize today. A significant technical advance came in 1918, when Hayakawa Juichi — the founder of what would become the KuSakura company — introduced double-weave fabric for the jacket. This construction method, which cross-weaves threads in two layers, dramatically increased durability and provided a more consistent grip surface, and remains the standard for competition judogi to this day.

White and Blue: The History of Color in Judo Competition

The original judogi was white — or more precisely, off-white, the natural color of cotton fabric bleached through repeated washing. Kano chose white deliberately: it eliminated visible distinctions between practitioners and kept the focus on technique rather than appearance. For most of judo’s first century, all competition was in white. The blue judogi was introduced at the elite level to solve a practical problem: in fast-moving competition, distinguishing which athlete had just scored a throw was difficult for judges and broadcasters when both wore white. The IJF introduced the blue judogi for one competitor per match at World Tour events, providing immediate visual distinction. The system has since become standard — at World Championships and Olympic Games, the two athletes wear white and blue, with the specific assignment determined by the draw or seeding rules. Below World Tour level, many national federations still conduct competition in white-only, and the requirement to own both a white and blue competition-legal gi is specific to athletes competing at IJF-governed events. Understanding how to follow judo competition is easier once the white-versus-blue uniform distinction becomes automatic — one color per athlete, consistent throughout the match, making scoring calls instantly attributable.

Frequently Asked Questions

What is an IJF-approved judogi?

An IJF-approved judogi is a judo uniform that has been tested by the International Judo Federation and certified as meeting the IJF’s published technical specifications for competition use. Approved gis bear a red IJF label with an optical code. Since April 1, 2015, all athletes at IJF World Tour events must wear an approved judogi — non-compliant uniforms result in disqualification from that event’s competition.

What fabric weight is required for an IJF judogi?

IJF judogi fabric must weigh between 650 and 750 g/m² and contain at least 70% cotton (synthetic fibers may comprise the remaining 30% maximum). The fabric must also meet durability standards — it must withstand competitive gripping and throwing without tearing. These specifications apply to both white and blue competition judogi.

Why do judo athletes wear blue and white uniforms?

The IJF requires one athlete in each match to wear a blue judogi and one to wear white, so that officials, video review systems, and spectators can instantly identify which athlete has scored a technique. Before blue judogi were introduced, both athletes wore white, making it difficult to attribute scoring calls in fast matches. The blue must meet a specific Pantone color standard (18-4051TCX to 18-4039TCX). Below World Tour level, many federations still compete in white-only uniforms.

Can I wear any brand’s judogi at an IJF event?

No. Only judogi from IJF-approved manufacturers that bear the official red IJF label are permitted at IJF World Tour events. Approved manufacturers include Adidas, Mizuno, KuSakura, Fighting Films, Matsuru, and others on the current IJF Official Supplier List. Not all models from an approved brand are certified — only specific models that were submitted and tested. Athletes must verify that their specific gi model carries the valid red label before competition.

When was the judogi invented?

Jigoro Kano designed the first judogi between 1882 and 1889 at the Kodokan in Tokyo, deriving it from Japanese kimono and traditional garments. By 1906 the judogi had its classic long-sleeve, traditional-cut form. The double-weave jacket fabric — the standard for modern competition judogi — was introduced by Hayakawa Juichi (founder of KuSakura) in 1918. The diamond-pattern (Hishisashi) weave common on modern judogi jackets was standardized in the 1970s.