To preserve the “physical future” of the Japanese language sequence
This proposal is intended to facilitate the long-term sales and support of Japanese keyboard layouts with bottom-row keys, submitted by Kawamura, Editor-in-Chief of keyboard specialist media Greenkeys and representative of the organization GreenEchoes Studio.
Ryosuke Kawamura Profile（JP）（EN）
This page is updated regularly.
– What is JIS Layout Alliance (JLA)? ｜TL;DR
- Purpose: To ensure cross-brand compatibility by clearly specifying two classes of Japanese bottom rows (bottom-row): 4.5u (span of stabilizer fulcrum ≈ 70mm) / 4.25u (span of stabilizer fulcrum ≈ 60mm ). The purpose is to make it easier to identify existing products, not to mandate changes.
- Significance: Replacement parts are more readily available, simplifying JIS keycap/keyboard operation.
- Participation categories: Founding / Participating / Distributors / Review (No restrictions. You can start with Review.)
- How to participate:Submit form → Confirmation email within approx. 5 business days.
- Badges: JLA badges can be displayed on product pages, etc. – Guide｜Downloads
- Tolerance Table: JLA 4.5u / 4.25u Tolerance Table (PDF)
For those considering shorter space bars: As a market reality, 2.75u (Convex included in Alice layout-compatible kits) has relatively better keycap availability in some cases. *JLA standard covers only 4.5u/4.25u.
Purpose of the JLA badge (non-compulsory and visible)
The JLA badge is not intended to encourage changes to current design policies. It is a mechanism to provide “an easy-to-read indication of replacement and compatibility after purchase” for both users and brands. The badge makes the axis of interchangeability (space bar length x stabilizer fulcrum span) easily visible at a glance, allowing the user to operate without compromising the enjoyment of customization.
Only JLA-450 / JLA-425 are applicable for display. The adoption of short space bar itself is respected.
How to Join
Listing in the JLA-450/425 “List of Participating Organizations” will be made only after prior confirmation.
Submit the necessary information such as brand/company name, contact person, official URL, desired status, JLA class (JLA-450 / JLA-425), etc. through the participation application form.
Immediately after submission, you will receive a confirmation email (in both Japanese and English). If there are any errors in the details, please let us know by replying to the email.
The secretariat will confirm the details of the application (brand name and JLA class consistency, validity of the URL). Additional questions will be asked if necessary.
If there are no problems with the application details, we will add a card to the List of Participating Organizations.
However, we will not publish without permission.
The card has an image + 2-column table (Brand/Company | Status | JLA Class | Official URL) configuration and is automatically reflected in the structured data (ItemList).
Please attach a badge to the product page that meets the JLA standards.
See the Badge Terms for details.
About short space bar (JLA’s concept)
For the time being, JLA is organized by 4.5u / 4.25u (stabilizer fulcrum span ≈ 70/60mm) for the purpose of “interchangeability of replacement parts and clarity of distribution”. This does not mean that the design concept and usability are aligned to one color.
We fully understand the rationale for a short space bar in Japanese input (conversion/non-conversion key operation) and respect the product policies of each company.
In addition, considering the practical aspects of post-purchase replacement/repair and availability of keycaps, there are situations where 2.75u is a better option when employing short space bars ( such as the 2.25u + 2.75u convex included in the Alice layout kit; the molds are clearly defined, and the stabilizer spans are also specified), (such as the 2.25u + 2.75u convex included in the kit for Alice layout, the mold is clear, and the stabilizer span is also defined).
Note that the JLA standard class (badge/registry indication) covers only 4.5u / 4.25u, giving priority to clarification of compatibility.
The adoption of the short space bar itself will be respected and information aspects will be shared as needed.
Governance
- Secretariat: Greenkeys (Coordination, Public and Contact Point)
- Technical collaborators (by area):.
- Keycaps: Providing reference dimensions (keycaps)｜Keyreative
- Stabilizers: Reference dimensions provided by Gateron
- PCB: Reference dimensions provided (mounting board)｜zfrontier(Carlxia)
The original drawings and illustrations of each company are the property of their respective right holders and are for display only (not for redistribution) on this site.
0. Introduction
First, we would like to express our respect to the brands that have consistently introduced Japanese layout mechanical keyboards in the Japanese market, especially to the manufacturers who have mass-produced and sold Japanese layout models with 4.5u class spacebars, supporting the culture of ‘selling mechanical keyboards with Japanese layout’ in the retail market.
Because such actual products have been distributed in Japan, we can now realistically discuss “wanting to provide replacement space bars and replacement keycaps for Japanese layouts as well.”
This document is neither an official statement from a specific manufacturer nor a binding industry standard.
This is an attempt to “organize the bottom row dimensions (e.g., space bar length, stabilizer fulcrum span) of Japanese keyboards already on the market today into easy-to-understand compatibility classes” from the perspective of the Japanese market.
This approach is not a request saying “please conform to new specifications from now on.”
It is for verbalizing existing actual dimensions as “compatibility classes” as they are, to make future supply of replacement space bars and keycaps, after-sales support, and resale even slightly easier.
- This does not require design changes, cost burden, or redesign obligations from brands or distributors.
- The purpose is to make it easier to make replacement space bars and keycaps by being able to say, “This class (e.g., 4.5u / stabilizer approx. 70mm span, 4.25u / stabilizer approx. 60mm span).
- Participation and involvement can start with “review participation (content confirmation and opinion sharing).” This is not asking for immediate “official commitment” or “approval.”
- When publishing brand names linked to specific dimensions (space bar length, stabilizer support point span, etc.), we will always conduct prior confirmation with the relevant brand/distributor side. We will not fix or publish without agreement.
This proposal is being compiled by Greenkeys (operated by Kawamura) as the coordinating contact from the perspective of Japanese user support and Japanese sequence localization sites.
Greenkeys is involved in layout supervision and feedback provision for Japanese layout models (consultation and verification of domestic JIS layout layouts, etc.) and judges that Japanese layouts need to remain not as “special, so postponed” but as something “sellable/fixable/enjoyable for a long time.”
The purpose of this document is to catalog the “reality” of the current Japanese bottom row and to facilitate the supply of replacement parts in the future.
For Users / For Users
Why is the JLA important?
Currently, if you purchase a keyboard with a Japanese layout, there are few compatible replacement parts available when the space bar breaks or you want to replace it with your preferred design.
The JLA solves this problem:
- You can get a replacement space bar.
- Third party keycaps can be used.
- Long-lasting and customizable
How to check if your keyboard is JLA compliant
- Check the manufacturer’s website for the “JLA-450” or “JLA-425” label.
- Check to see if JLA badge is listed on product page
- Find your own keyboard brand in the list of participating companies
Advantages of purchasing a JLA compliant keyboard
✓ Replacement space bars will be available in the future
✓ Keycap manufacturers will increase the number of JLA-compatible products
✓ Long-term support and repairability
✓ Contribute to the development of Japanese keyboard culture
How to communicate requests to manufacturers
Your voice is the driving force behind JLA:
- Use hashtags #JLA and #JISLayoutAlliance on social networking sites
- When considering a purchase, “Is it JLA compliant?” and inquire
- Evaluate JLA response through reviews and feedback
1. mission
Key Points
・The JIS standard (JIS X 6002) defines key positions and names, but not the physical specifications.
As a result, the bottom row of the Japanese layout is different from manufacturer to manufacturer, and there is no compatible space bar.
The JIS Layout Alliance aims to create a common physical baseline even for the space bar of JIS layouts, and to return Japanese layouts to a “culture that can be nurtured”.
A keyboard with a Japanese layout is a computer keyboard with a key layout that conforms to the JIS X 6002 Information Processing Keyboard layout, a standard established by the Japanese Industrial Standards (JIS).
However, JIS X 6002 defines mainly the layout of “what should exist in what position as a key” (the arrangement and names of character keys such as alphabet, kana, and symbols), and does not go into the physical specifications.
For example, “hardware form” such as space bar lengths, bottom row key assignments, and stabilizer locations, dimensions, and tolerances are not specified.
As a result, the bottom rows of Japanese layouts (around the space bar, non-conversion, conversion, and kana keys) have not been standardized at all, and have been different from manufacturer to manufacturer/model to model for many years.
The disparate physical specifications make it nearly impossible to substitute parts such as replacement space bars, keycaps, plates, and PCBs from other manufacturers.
A particular problem is the length of the space bar.
In ANSI layouts (commonly used in English-speaking countries), the space bar is approximately 6.25u in length, which is the de facto standard, and a culture of keycap replacement has been established among the products of various companies.
Users can freely customize the space bar and can safely replace it with third-party products.
This is also true for the manufacturers who design and sell keycaps.
As a result, keyboards are not “buy and play” objects.
On the other hand, in Japanese-language layouts, the space bar is often shorter, such as 4.5u or 4.25u, and the length and support (position of stabilizers) of the space bar varies from product to product.
Because of this, the compatible space bar itself is virtually non-existent on the market.
In other words, only Japanese-language sequences are physically isolated.
Furthermore, Japanese users have a strong culture of quickly switching between “Kana” and “Eisu” with a single key, and many find it difficult to use without a “bottom row of Japanese layout (including the non-conversion/conversion key)” to begin with.
In addition to this, the “half/full-width(半角/全角)” key is indispensable for Windows users.
This is a barrier to entry for foreign manufacturers, inducing them to make the decision that Japanese-language layouts are too costly and will be an afterthought.
This situation is disadvantageous to users who want to choose Japanese-language layout, and as a result, it has encouraged design decisions that “Japanese-language layout is too cumbersome to adopt” or “Japanese-language layout is only available in limited models.
In the long run, this will reduce the viability of the Japanese sequence itself.
The JIS Layout Alliance is an effort to address this problem by “creating a minimum common physical baseline for the space bar of Japanese layouts alone.
The goal is not “standardization for standardization’s sake,” but rather “to keep Japanese-language sequences alive in a form that can be sold, made, and played with in the future.
The goal is to return the Japanese language sequence to a culture that can be properly tended to and nurtured, rather than one that is “special and unwieldy.
2. why do it now?
Key Points
・The low-profile market has grown rapidly, but compatibility has rather collapsed.
Although the number of Japanese-language models is increasing, there is no common standard for the dimensions of the bottom row.
If left unchecked, “Japanese-language layouts are too costly and cumbersome, so they will be put on the back burner” will become fixed, and Japanese-language layouts will taper off from the market.
Today, the market for low-profile keyboards is expanding rapidly.
Kailh choc v2, Gateron Low Profile (2.0 / 3.0), and other low-profile key switches are available from various companies, each with its own stabilizer structure, plate design, and PCB cutout.
The result is a rather difficult situation for low-profile mechanical keyboards, including ANSI.
- Low-pro is not compatible, but rather “low-pro is incompatible”.
- Manufacturer A’s space bar does not match manufacturer B’s stabilizer position
- No replacement keycaps or spare parts on the market
At the same time, the number of brands that officially offer Japanese-language sequences is increasing.
Nevertheless, there is still no cross-industry agreement “let’s make this the standard” for the bottom row of Japanese-language sequences.
This is especially true for the size of the space bar, which can be 4.5u or 4.25u, and varies from model to model.
Because of this, it is difficult for Japanese users to enjoy the fun of buying a keyboard and later replacing its parts to their own liking.
Manufacturers are more likely to judge that the return on Japanese-language layouts is small compared to the cost, and the priority for Japanese-language layouts will be reduced.
In other words, we are now at the crossroads of whether to “save the Japanese sequence here and create a common assumption” or to “leave it as a special treatment again.
3. proposed baseline
Key Points
– Clarify that there are two major systems of dimensions that are realistically used for Japanese-language spacebars.
- JLA-450: 4.5u spacebar length / approx. 70mm stabilizer fulcrum span
– JLA-425: 4.25u spacebar length / approx. 60mm stabilizer fulcrum span
– When designing and selling new Japanese keyboards in the future, it is recommended to match either “JLA-450” or We recommend that future Japanese-language keyboards be designed and marketed to match either the “JLA-450” or “JLA-425”.
We would like to agree not to add any more new proprietary dimensions (e.g., intermediate sizes or spans).
We do not bind each company’s know-how in terms of stabilizer mechanisms, materials, etc. What we want to share is only the interface dimension of “where the fulcrum is located.
This is the core of JIS Layout Alliance.
The first thing we need to agree on is how to handle the “physical interface” of the bottom row of the Japanese layout, especially around the space bar.
This is not asking manufacturers to “please change your design.”
This attempts to verbalize the actual bottom row dimensions (space bar length and stabilizer support point span) of Japanese layout models already in mass production and sale as “compatibility classes” as they are.
In other words, the purpose is not “someone imposing a new standard from above,” but “making it easier to supply replacement space bars and keycaps by organizing existing actual dimensions.”
A prerequisite for joining the JLA is that your company’s keyboard and keycap space bar sizes conform to the drawings below to some degree and are determined to be compatible.
3.1 Spacebar Length Class
First, organize the length of the space bar as follows
- We treat 4.5u size space bars as one of the basic sizes for Japanese layout bottom rows. We call this the JLA-450 class.
- For historical reasons and compatibility with existing products, we also treat 4.25u size space bars as an official class. We call this the JLA-425 class.
It is important to note that we are not talking about “only 4.5u is correct and 4.25u is truncated”.
We take the approach of positioning 4.5u (JLA-450) as the future reference axis while keeping 4.25u (JLA-425) as a realistic option as well.
This will prevent Japanese keyboards in the market from being treated as “incompatible” at once.
While various other space bar lengths exist, for Japanese layout keyboards newly designed and developed in the future (lines from brands and distributors involved in the alliance), we basically recommend basing them on either the JLA-450 or JLA-425 class.
3.2 Stabilizer fulcrum span (lateral distance)
Just as important as the length of the spacebar itself is “the positioning of the two points on either side that support it under the spacebar.
Specifically, the distance between the center and center of the fulcrums (i. e., stabilizer and auxiliary feet) on either side of the spacebar center switch (i.e., stabilizer fulcrum span ) has a direct effect on keycap compatibility and plate/PCB design.
Currently, the following two major spans of Japanese sequences are in existence.
- JLA-450
・Space bar length: approx. 4.5u (approx. 85mm)
・Stabilizer fulcrum span: approx. 70mm - JLA-425
・Space bar length: approx. 4.25u (approx. 80mm)
・Stabilizer fulcrum span: approx. 60mm
JIS Layout Alliance defines these two spans as official “compatibility classes” and believes that new Japanese layout keyboards should conform to either JLA-450 or JLA-425.
This is so that each manufacturer can follow their own layout philosophy (whether they want to use 4.5u or 4.25u) while still allowing users to obtain replacement parts later.
Conversely, we want to avoid further increasing proprietary spans that do not fit either JLA-450 or JLA-425.
If such “third physical specifications” increase without limit, Japanese layout users will be isolated again.
This approach of “clearly documenting two classes” becomes the foundation for keycap manufacturers, space bar individual manufacturers, and PCB/plate designers to confidently claim “JIS compatibility.”
The reasons why this classification is important are as follows
- On the keycap/space bar side, by preparing two variations for JLA-450 and JLA-425, they can realistically supply replacement space bars for Japanese layout users.
- On the PCB and plate design side, they only need to declare “whether to go with JLA-450 or JLA-425” at the beginning, eliminating the need to devise new proprietary dimensions.
- Users only need to understand “whether their keyboard is JLA-450 or JLA-425 type” to be able to search for spare parts later.
- In other words, it is easier to establish a culture of “customization after purchase” even with Japanese-language layouts.
What JIS Layout Alliance wants to protect first is providing this “common physical interface expression of JLA-450 / JLA-425” to both the industry and user sides.
3.3 Technical Specifications and Tolerances
This section describes the technical specifications and crossings of the JLA-450/425.
3.3.1 JLA-450 Detailed Specifications
Dimension Definition
- Total length of space bar : 85.60mm±0.20mm (4.5u)
- Stabilizer fulcrum span 70.0mm ± 0.20mm
- Measurements: Distance from center to center of stabilizer housing
- Key switch mounting position: center of space bar
- Stabilizer placement: in line with the key switch
3.3.2 JLA-425 Detailed Specifications
Dimension Definition
- Total space bar length: 80.11mm±0.20mm (4.25u)
- Stabilizer fulcrum span: 60.00mm ± 0.20mm
- Measurement method : Center to center of stabilizer housing
- Key switch mounting position: center of space bar
- Stabilizer placement : in line with key switch
Measurement Reference Points
- Criteria: PCB Surface
- Horizontal reference: center axis of key switch
- Measuring instrument : Digital caliper (0.01 mm resolution)
3.3.3 Technical Drawings
3.3 What not to ask for
I want to make it clear here that we do not intend to go into the internal know-how of each company.
- Mechanism of the stabilizer (wire bending, housing fixing method, lubrication method, auxiliary pin shape, etc.)
- Plate holding structure and fixing clip shape
- Material selection for housing and wires
We respect this kind of content as unique to each brand. We do not require that they be published or standardized.
JIS Layout Alliance only wants to share the interface dimensions (where the fulcrum should be).
3.4 Current Issues
Currently, differences in stabilizer support point spans are isolating only Japanese layouts.
Please refer to the diagram below.
As shown, 4.5u space bars and approximately 4.25u space bars have different stabilizer intervals (support point spans).
Based on this fact, we propose two classes , JLA-450 / JLA-425.
3.5 Request to Keycap Keyboard Stabilizer Brand
Request to Keyboard Brands
JIS Layout Alliance recommends the following for brands that design and sell new Japanese layout products in the future.
- When designing new Japanese layout models, please conform to either the JLA-450 or JLA-425 specifications.
(This means aligning the combination of spacebar length and stabilizer pivot span to one of these standards)
These are widely adopted in Japanese layout products currently distributed in Japan, and we consider them to be standards that make it easier to ensure future compatibility for spacebar and keycap replacements. - Conversely, we would like to avoid adding new proprietary dimensions (e.g., 4.4u / 65mm fulcrum span) that do not fall into either of the above two classes.
This would divide Japanese-language users into “yet another standard” and make the supply of compatible parts more difficult.
Request to Keycap/Spacebar Manufacturers
We would like to request the following cooperation from brands, factories, and designers who make keycaps and single space bars.
- For space bars, we recommend having a lineup of two variations: JLA-450 compatible (4.5u / ≈70mm span) and JLA-425 compatible (4.25u / ≈60mm span).
This will enable Japanese layout users to obtain replacement space bars even for existing keyboards. - However, this does not mean you cannot claim “JLA compliance” unless you support both classes. Supporting either one is sufficient.
- We aim for a state where users who want to purchase Japanese layout replacement keycaps can see labels like “JLA-450 compatible,” “JLA-425 compatible,” or “450/425 both compatible” and choose space bars/key sets that match their keyboards.
- We do not require disclosure or uniformity of internal know-how such as stabilizer housing construction, cross stem side wall shape, wire fixing method, etc.
We only want to share the “mounting position dimensions” such as “space bar length” and “stabilizer fulcrum span (distance between centers of right and left fulcrums).
The goal of the JIS Layout Alliance is to create “a world where replacement space bars/keycaps are properly distributed for Japanese layouts.
The ability to have multiple SKUs on the keycap side is a critical part of that realization.
Dimensions, brand names, and the association with “JLA-450 / JLA-425” naming handled in this draft will not be published without approval from each brand.
The page is only a suggestion to facilitate long-term support of Japanese-language keyboards (JIS bottom row), and is not a unilateral request for design changes or obligations from a specific manufacturer.
4. scope (do’s and don’ts)
Key Points
・Clearly document two classes (JLA-450 / JLA-425) that combine “space bar length (4.5u / 4.25u)” and “stabilizer support point span (approximately 70mm / approximately 60mm)”.
・Enable compatibility maintenance by having new products conform to either of these.
・Do not interfere with company mechanisms, materials, or implementation know-how at all.
・Align only the minimum “common interface” to create culture (foundation).
Here, JIS Layout Alliance clarifies “do’s” and “don’ts”.
what to do
- Clearly document the combination of space bar length and stabilizer support point span in Japanese layout bottom rows as two classes (JLA-450 / JLA-425)
- JLA-450: 4.5u size (approx. 85mm) / approx. 70mm stabilizer span
- JLA-425: 4.25u size (approx. 80mm) / approximately 60mm stabilizer span
- Recommend that Japanese layout keyboards newly designed and sold in the future basically adopt either JLA-450 or JLA-425
- To prevent further disruption of new proprietary sizes and spans
What not to do
- Differences between switch generations themselves, such as Kailh choc v2 / Gateron Low Profile 2.0 / 3.0, are not standardized.
- We do not request the disclosure or standardization of the stabilizer’s structure or materials themselves.
- Firmware and keymaps (e.g., kana/eisuji switching logic) are also excluded.
By clearly delineating this line, manufacturers can create an environment in which users can easily enjoy their products while preserving their “own identity.
5. Display of JLA Badges
For companies, designers, and brands that have agreed to participate, we ask that you display a “label” (badge) supporting physical compatibility with Japanese keyboard layouts.
The objective is to achieve a state where we can declare that “this product complies with the JIS Layout Alliance (JLA-450 / JLA-425).”
Regarding badge download posting rules, the guidelines are summarized below.
Q&a / Frequently Asked Questions
The following are frequently asked questions from manufacturers, distributors, and designers, along with our thinking.
これに「参加する」と公式にこの規格に同意したことになりますか？/Does “participating” in this officially constitute agreement to this standard?
No.
We have established a “review participation” process where we share proposal details (such as dimension classes and notation methods) and ask you to inform us of any concerns.
This is not a binding commitment asking “please officially agree” or “please redesign with these dimensions.”
We would appreciate it if you could switch to the “Participating” status after agreeing to the proposal.
勝手に寸法や社名を“標準クラス”として公開されたりしませんか？/Are dimensions and company names being published as “standard class” without permission?
No.
When writing externally about specific values such as space bar length or stabilizer pivot span in conjunction with brand names, always obtain prior confirmation from the relevant brand or its agency.
We will not publish fixed statements like “this company = JLA-450” or “this model = JLA-425” without agreement.
このアライアンスは、メーカーに設計変更を求める取り組みですか？/Is this alliance an initiative to request design changes from manufacturers?
No. It’s the opposite.
The goal is not to “align with new specifications,” but rather to organize the actual dimensions of commercially available Japanese keyboard layouts (e.g., 4.5u + approx. 70mm stabilizer span, 4.25u + approx. 60mm stabilizer span) under the class names JLA-450 / JLA-425.
This is positioned as “cataloging” to make it easier to supply replacement space bars and keycaps in the future with those dimensions without denying current products.
この提案は誰がまとめていますか？ 個人のアイデアですか？/Who is compiling this draft? Is it an individual’s idea?
Greenkeys (operated by Kawamura) is compiling this as a coordination point for the Japanese market side.
Greenkeys is involved in supervising and supporting the localization of Japanese keyboard layouts (including consulting and providing feedback on domestic JIS layouts). We are organizing this proposal with the goal of preserving Japanese layouts not as “special cases to be put on the back burner,” but in a form that ensures they remain “long-lasting, repairable, and enjoyable.”
This document is not a binding industry standard, but rather a shared memo regarding bottom row dimensions for the Japanese market.
代理店としてはいま何を返せばいいですか？ 賛成・反対をはっきり言う必要がありますか？/ As an agency, what should we respond with now? Do we need to clearly state whether we agree or disagree?
At this point, declarations like “we officially agree/disagree” are not necessary.
What would be most helpful is a response like:
“We are positive about the direction. When you reach the stage of specifically publishing dimensions and class names, please make sure to check with us in advance.”
This is treated as “review participation (content confirmation and concern sharing)” rather than “binding agreement.”
This is positioned to think together about after-sales support for Japanese layouts and replacement space bar supply while reducing risks for distributors and manufacturers.
We would appreciate it if you could switch to the “Participating” status once you agree to this proposal.
4.5u / 4.25u 以外のスタビライザー間隔を使った日本語配列キーボードは、JIS Layout Alliance準拠になりますか？/Do Japanese keyboard layouts using stabilizer spacings other than 4.5u / 4.25u comply with the JIS Layout Alliance?
Not at this point.
JIS Layout Alliance treats only the following two as official classes, based on Japanese layout keyboards actually distributed in the Japanese market.
- JLA-450: Space bar length 4.5u / stabilizer support point span approximately 70mm
- JLA-425: Space bar length 4.25u / stabilizer support point span approximately 60mm
If we further increase the number of new stabilizer pivot spans (for example, adopting a 4.25u size spacebar but with a 55mm stabilizer interval), it will again fragment the compatibility of replacement spacebars and keycaps for Japanese layouts.
Especially in the low-profile area where proprietary dimensions tend to proliferate, we have a policy of not considering new dimensions other than these two classes as “JIS Layout Alliance compliant” in the future.
This is a rule to protect backward compatibility while not increasing variations further.
スペースバーを2つのキーに分割した「分割スペース」は、JIS Layout Allianceの対象になりますか？/Does the “split space” (a spacebar divided into two keys) fall under the JIS Layout Alliance’s scope?
Currently treated as “out of scope.”
The reason is that split space configurations (dividing 4.5u equivalent into 2.25u+2.25u or 2.0u+2.5u, dividing 4.25u equivalent into 2.0u+2.25u, etc.) can be handled with key sizes and stabilizers common in ANSI regions, thus avoiding the problem of Japanese layouts needing isolated special space bars.
What JIS Layout Alliance wants to protect first is the zone with compatibility risks unique to Japanese layouts: “single short space bar + dedicated stabilizer width.”
Since split space methods avoid that risk in the first place, they are positioned not as “not recommended” but as “separate from what this alliance is trying to rescue.”
In the future, we are considering documenting a note that “split space is recognized as an alternative approach that solves compatibility risks independently” (equivalent route), but we prioritize first establishing JLA-450/JLA-425 as industry common language.
2.5u／2.75uはJLAの対象ですか？
The standard class (badge/registry) only covers 4.5u/4.25u, with priority given to clarifying compatibility. We respect the use of short space bars, and in terms of practical availability, there are situations where 2.75u is an easier choice (e.g., 2.25u + 2.75u Convex in Alice layout compatible kits).
矢印キー（↑を1段上に逃がすか、横一列にそろえるかなど）もアライアンスの対象になりますか？/ Do arrow keys also fall under the Alliance?
Not currently covered.
In 65% / 75% class keyboards, many manufacturers maintain case sizes and exterior dimensions derived from ANSI layouts while localizing only the PCB and layout for Japanese layout versions.
As a result, the arrow key area (whether only the ↑ key goes up one row, aligns horizontally, where to place PgUp/PgDn, etc.) strongly depends on case design, brand personality, and product concept.
This area is not the kind of problem that can be “rescued with one replacement part” like space bars, but is the character of case design and key placement itself.
JIS Layout Alliance respects this as each brand’s uniqueness rather than restricting it at this stage.
What we want to protect first is that the bottom row unique to Japanese layouts—a short single bar plus dedicated stabilizer width—does not become irreparable.
既存のキーボードを買い替える必要がありますか？/ Do I need to replace my existing keyboard?
The JLA is a recommendation for “products to be designed and sold in the future” and does not negate keyboards already purchased.
However, since JLA-compliant products will be the ones for which replacement parts are more readily available in the future, we hope that you will use this information as a reference for your next purchase.
JLA準拠のキーキャップはいつ頃市場に出ますか？/ When will JLA-compliant keycaps be available on the market?
We are currently in discussions with several brands.
ロープロファイル以外の通常高さ（Cherry MX互換）のキーボードにも適用されますか？/ Does this also apply to standard height (Cherry MX compatible) keyboards, not just low-profile?
Yes, it applies. JLA applies to “the physical dimensions of the bottom row of a Japanese array” regardless of the height or type of switch.
Both regular-height and low-profile keyboards with Cherry MX compatible switches can comply with JLA-450 or JLA-425.
Administrative Office
JIS Layout Alliance Management Office: GreenEchoes Studio
Representative: Ryosuke Kawamura
Address: 2-1-5 Jindoji Minami, Chuo-ku, Niigata City, Niigata Prefecture
7. glossary
Japanese bottom row (JIS bottom row)
The bottom row in Japanese layout. The area where space bar, muhenkan, henkan, kana keys, etc. are arranged.
4.5u / 4.25u
キーボード設計で使われるキー幅の単位「u」（1u＝標準的な1キーの幅）をもとにしたスペースバーの長さ表現。4.5uは約4.5キー分、4.25uは約4.25キー分の長さのスペースバーを意味する。日本語配列では歴史的に短いスペースバー（3.75u〜4.5u）が使われることが多い。
Stabilizer
A component that supports long keys such as space bar and Shift from the left and right to prevent them from being rattled. The structure differs from manufacturer to manufacturer, such as wire type, auxiliary foot type, etc.
Stabilizer span
The horizontal distance between centers of support points (stabilizer receivers or auxiliary foot contact points, etc.) placed left and right on the back of the space bar. JIS Layout Alliance aims to document this span as JLA-450 / JLA-425 and not increase others further.
Low profile
It refers to low profile mechanical switches and overall keyboard designs that are based on them. Typical examples include Kailh choc v2 and Gateron Low Profile series. The physical specifications are very different from those of general Cherry MX standard-compliant key switches, and in many cases, conventional compatible parts cannot be used without modification.
Finally.
The JIS Layout Alliance is an initiative to allow keyboard manufacturing brands and third-party keycap makers to share ‘the same premises’ regarding the bottom row of Japanese layouts.
By doing so, we hope to make it commonplace in Japan to “cultivate the keyboard as more than an input device, but also as a pleasure,” similar to the 6.25u culture in the rest of the world.
We will support both the industry side and the user side to ensure that Japanese language sequences will remain in the future.
Licenses / Rights notices
The description (text) portion of this page is provided under CC BY 4.0. Please give credit to “JIS Layout Alliance (Greenkeys)” when quoting.
However, drawings, images, and numerical values provided by third parties (e.g., keycap dimensions, stabilizer dimensions, PCB reference) belong to the original copyright holder and are not subject to redistribution or secondary use (display only). Individual rights notes will be assigned to each drawing as necessary.
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Credit example: Source: JIS Layout Alliance (Greenkeys), “JLA-450/425 Overview”, CC BY 4.0