How to choose keycaps for your mechanical keyboard: Reddit's guide

Choosing the right keycap set for a mechanical keyboard means balancing profile height, material, layout compatibility, size, and legend durability. Miss one of these details and the set may not fit, feel uncomfortable, or wear prematurely. This guide brings those decisions together so choosing a custom set is based on the keyboard itself rather than appearance alone.

Check keycap fit before buying

Compatibility comes first. A keycap set may look ideal online but fail to mount if the switch stem, layout, or bottom-row dimensions do not match the target keyboard. Checking all three before buying avoids returns and delays. the keycap compatibility guide from Krome Keycaps explains the process, including stem identification and layout-specific sizing.

Identify your keyboard switch mount

Most aftermarket keycap sets use the Cherry MX-style cross-shaped stem. It also fits compatible switches from Gateron, Kailh, and Outemu, making it the most widely supported standard in the mechanical keyboard market. Many enthusiast sets, including those discussed in custom keyboard keycaps for beginners on reddit, follow this design. Remove one existing keycap and inspect the exposed stem directly.

• Cherry MX-style stem A cross-shaped post compatible with most aftermarket keycap sets and common mechanical keyboards.
• Topre stem A circular electro-capacitive mount requiring dedicated keycaps or an adaptor; standard MX-compatible sets will not attach correctly.
• Alps stem A rectangular post found on older and specialist boards. It is incompatible with Cherry MX keycap sets and requires Alps-specific options.
• Membrane and rubber-dome keyboards These do not accept MX-style keycaps. Some proprietary and optical switches also require an individual compatibility check.

Krome Keycaps sets are designed for Cherry MX-style switches and compatible alternatives, but fit should still be confirmed against the specific keyboard model. The the complete keyboard profile guide is useful alongside stem identification, particularly when comparing profile and material before purchase.

Measure bottom-row keycap size

After confirming the switch stem, check the bottom row. Keycap widths are measured in units, with 1u equalling approximately 18–19 mm; modifier keys and the spacebar vary most often between keyboard models.

• Spacebar size 6.25u is the most common standard, while 6u and 7u versions also exist and are not interchangeable. Confirm this measurement first.
• Standard modifier width Ctrl, Alt, and Windows or Meta keys typically measure 1.25u. Some gaming keyboards use a 1u alternative for the Windows key.
• Right Shift size This is usually 2.75u on full-size keyboards but commonly 1.75u on compact 65% and 75% layouts, so compact users should verify it explicitly.
• ISO versus ANSI Enter ANSI Enter is a horizontal 2.25u key. ISO Enter is a taller, L-shaped two-row key that requires a dedicated mould and included keycap.

A 104/105-key set covering both ANSI and ISO configurations can support many 60%, TKL, and full-size boards from one purchase, provided the bottom-row and spacebar dimensions match the target keyboard. The black and blue PBT keycap set from Krome Keycaps includes a 6.25u spacebar plus ISO and ANSI configurations, making it a useful example of broad layout coverage across different keyboard sizes.

PBT or ABS keycap material

Material choice shapes the long-term typing experience more than almost any other variable after profile. The two dominant options, PBT and ABS, differ in texture, sound, wear resistance and manufacturing behaviour, so each suits different priorities.

Durability and texture compared

PBT keycaps are denser and better at resisting oil from finger contact. High-use keys such as WASD and the spacebar therefore retain a consistent matte texture for longer during daily use.

ABS, in contrast, can develop a glossy finish on heavily used keys through normal contact. That is a property of the material, not a defect, but it is worth considering when durability is a priority. ABS is lighter and typically more affordable, with a wider range of vivid colours available at lower price points.

The choice hinges on how the keyboard will be used. PBT suits users who value wear resistance and a stable surface texture, while ABS suits those who prefer bold colour and a lighter feel.

Double-shot PBT combines the material’s durability with a legend moulded as a separate structural layer, so the marking cannot wear away through typing. Unlike single-shot printing, the legend is not simply applied to the surface; it is formed within the keycap body during manufacture. On RGB builds, double-shot PBT legends can also allow backlighting to pass through without sacrificing legend durability.

Sound and thickness differences

Wall thickness is a direct acoustic variable, and it interacts with material to shape a keyboard’s sound during typing. Keycap walls of 1.5 mm or more tend to produce a deeper, more solid sound by damping higher-frequency resonance. Thinner caps at 1.3 mm or below often sound higher-pitched or more plasticky, regardless of the switches beneath them.

ABS produces a naturally higher-pitched sound compared with PBT, which gives PBT a deeper character. Switches, plate material and case construction still have a substantial effect on the final result, however, so keycaps are only one part of the acoustic picture.

Brands such as Akko have built a following around thicker PBT keycaps paired with dye-sublimated legends. Thicker keycaps add mass, helping to stabilise each keystroke while reducing wobble and hollow resonance during extended typing.

New PBT stems may fit snugly at first because of approximately 1–2% material shrinkage during production. This usually settles with normal use, making fit and stem compatibility worth checking before buying a replacement set.

Choose a keycap profile for feel

A keycap profile determines the height, row angle and top-surface shape of every key on a keyboard, which in turn affects finger extension during typing, comfort over long sessions, sound and the board’s visual character. Understanding the common profiles makes it easier to compare which types suit a particular layout, hand size and use case.

Sculpted keyboard profiles

Sculpted keycap profiles vary in height and angle from row to row, following the natural arc of finger movement. OEM profile ships on most pre-built mechanical keyboards, while Cherry and SA offer different height and sound characteristics for those buying keycaps from aftermarket ranges. GMK keycaps use the Cherry profile and remain popular in enthusiast group buys because the low sculpted shape balances typing comfort with acoustic density.

Cherry profile is approximately 9.4 mm tall, notably lower than OEM. SA profile is the tallest of these sculpted keycap profiles at approximately 16.5 mm, with spherical tops that cradle the fingertip; it produces a deep, resonant sound, although extended sessions may call for a wrist rest.

• Cherry profile Approximately 9.4 mm tall; low sculpted rows, preferred by enthusiasts for gaming and productivity because of the reduced finger extension and familiar feel.
• OEM profile Approximately 11.9 mm tall; the standard sculpted profile shipped on most pre-built mechanical keyboards, widely familiar and generally comfortable for new users.
• SA profile Approximately 16.5 mm tall; spherical tops and deep sculpting create resonant sound and a vintage aesthetic, best suited to a keyboard with wrist support.
• Top-surface shape Cylindrical tops guide columnar finger movement for precise typing, while spherical tops cradle the fingertip more evenly during extended sessions.

Profile choice interacts with hand size and desk posture, so the same set will not feel identical to every user. Testing several options on the same keyboard before committing to a full set is the most reliable approach when budget allows. This holds especially for users who switch between gaming and productivity on one board.

Uniform profiles for flexible layouts

Uniform profiles use the same height and shape in every row, allowing any keycap from the set to move to any position without changing the typing experience. They suit non-standard layouts such as Dvorak, Colemak and ortholinear arrangements, where key positions differ from the standard QWERTY grid. DSA is a low uniform profile at approximately 7.6 mm, making it useful on ortholinear layouts where sculpted rows would create an inconsistent surface. XDA sits slightly taller at approximately 9.1 mm and has a wider top surface, providing more fingertip contact during typing.

Uniform profiles also simplify buying keycaps for split or custom layouts because there is no row-specific orientation to track. Any keycap can sit in any row and retain the same feel.

Height, posture and typing comfort

Taller sculpted profiles such as SA may require a wrist rest to maintain a neutral wrist angle during extended typing, while lower profiles such as Cherry and DSA can usually be used without one. Profile height, chair height and desk surface matter most for users who type for several hours each day. Hand size also plays a role: shorter profiles reduce the distance fingers travel between keys, which can benefit users with smaller hands or those managing wrist strain. When choosing a profile for a gaming or productivity build, consider posture and session length alongside the typing preferences that will shape daily comfort.

Match keycap layouts to your keyboard

Layout compatibility determines whether a keycap set covers every position on a keyboard with the correct shapes and sizes. Before buying keycaps, check the Enter shape, Shift size, modifier widths, and spacebar length.

ANSI and ISO keycap differences

ANSI and ISO layouts share many keycap sizes, but their most important coverage points differ. An ANSI-only set will not include the ISO Enter or the smaller ISO left Shift, leaving those positions uncovered on a UK or European keyboard.

• ANSI Enter A horizontal, single-row key measuring approximately 2.25u. It does not fit ISO keyboard positions, which require a taller, L-shaped, two-row key with its own mould.
• ISO Enter An L-shaped, two-row key found on UK and European keyboards. It requires a keycap set that explicitly includes this mould rather than a generic ANSI-only set.
• ISO left Shift and Alt Gr ISO layouts use a smaller left Shift and include Alt Gr. Both must be present for complete keyboard coverage.

A 104/105-key set offering both ANSI and ISO configurations covers most 60%, TKL, and full-size boards from one purchase, provided the bottom-row modifiers and spacebar dimensions also match. JIS keyboards create a separate compatibility challenge: their short spacebar and several unique key sizes make standard ANSI or ISO sets unsuitable in most cases, so a purpose-built JIS set is the practical option. French Canadian keyboards likewise require ISO-CA sets with correctly placed accented legends rather than a generic ISO configuration.

Compact keyboard bottom rows

Compact keyboards, including 60%, 65%, and 75% layouts, often use non-standard bottom rows that differ from full-size dimensions. The difference comes down to right Shift size and modifier widths, which frequently depart from the values used on a 100% or TKL keyboard. Compare the included key sizes with the actual keyboard measurements before buying keycaps; this prevents the most common fit failures on compact builds.

• Right Shift on compact boards Typically 1.75u on 65% and 75% layouts, compared with the 2.75u standard on full-size keyboards. Broad compatibility requires sets that include both sizes.
• Spacebar width 6.25u is the most common standard, while 6u and 7u variants also exist. They are not interchangeable, so confirm the measurement for each keyboard.
• Standard modifier width Ctrl, Alt, and Windows or Meta keys are typically 1.25u. Some gaming keyboards replace the Windows key with a 1u alternative that not all sets include.
• 60% layout coverage A full 104/105-key set with ANSI and ISO options covers most 60% boards when the bottom-row widths and spacebar dimensions match the board's design.

Checking these measurements against the actual keyboard gives the most reliable result. Manufacturers sometimes vary bottom-row dimensions within the same form factor, so the keyboard model is a better reference than its size category alone.

Legends and RGB lighting

Legend durability follows a clear hierarchy. Pad-printed legends are the least durable and can wear through sustained typing; laser-engraved legends last longer but offer limited colour application. Dye-sublimated keycaps absorb the legend into the keycap material, producing fade-resistant results, while double-shot legends are moulded as a separate layer and do not wear away through normal use. The legend method should match how intensively the keyboard will be used, especially on high-frequency positions such as WASD and the spacebar.

RGB lighting compatibility depends on legend construction rather than stem type or layout. Double-shot translucent legends, clear legend windows, and pudding-style designs with translucent sides can transmit light through the keycap and across the desk surface. Dye-sublimated legends block light in the printed area, creating a backlit silhouette rather than a fully illuminated legend.

Build a gaming keyboard with keycaps

Gaming builds introduce priorities that differ slightly from a pure typing setup.

Fast profiles for gaming

Lower keycap profiles reduce the distance fingers travel between keys during rapid input. That can feel faster and less tiring during prolonged gaming. In keycap recommendations shared by gaming communities, Cherry profile appears consistently as a strong option: it is lower than OEM and SA while retaining sculpted row angles. Both Cherry and OEM profiles are common in gaming builds, though Cherry's lower height can feel faster.

• Cherry profile At approximately 9.4 mm, this low, sculpted option reduces finger extension and is regularly recommended for gaming and fast typing.
• OEM profile At approximately 11.9 mm, OEM is the familiar mid-height option found on most pre-built keyboards. It remains a comfortable all-round choice for mixed use.
• SA profile At approximately 16.5 mm, SA offers a distinctive visual presence and deep, resonant sound, but its height may reduce comfort during extended gaming without a wrist rest.
• DSA profile At approximately 7.6 mm, this uniform, low profile suits users who prefer minimal finger travel and a flat typing surface across every row of the keyboard.

Switch choice remains the dominant factor in gaming performance, while profile height shapes the physical typing experience on every keypress. A lower profile such as Cherry or DSA will generally feel more responsive during fast input than SA.

RGB-ready keycap designs

RGB compatibility depends on the way the keycap legend is constructed, not on the switch type or keyboard layout. Double-shot keycaps with translucent legend windows allow light to pass through clearly, producing sharp illuminated legends at different RGB brightness levels.

Pudding-style keycaps extend the RGB effect with translucent sides that diffuse light across the keycap surface and onto the desk. These usually use a dual-layer ABS design, with a semi-transparent lower section that spreads light in multiple directions. The result is more ambient and less focused than a conventional backlit legend, which suits lighting-led gaming or content-creator desk setups where the keyboard is both a functional tool and a visual element.

That can look effective on some RGB setups, especially with high-contrast colour combinations, but the legend itself does not transmit light. For builds where maximum RGB clarity matters, double-shot construction with translucent legend windows remains the more consistent option across different lighting conditions and colour preferences.

A compatible Krome Keycaps option

Krome Keycaps' black-and-blue double-shot PBT set shows how these considerations combine in one product decision. The set uses the familiar OEM profile and includes RGB-compatible legends with double-shot construction, making the legend permanent while keeping the lighting clearly visible through the keycap surface. ISO and ANSI configurations are included, the spacebar uses the 6.25u standard, and coverage extends across 104/105 keys for 60%, TKL, and 100% keyboard sizes when the layout dimensions match.

The set is designed for Cherry MX-style mechanical switches and compatible alternatives from Gateron, Kailh, and Outemu. It uses the broad stem standard found across many aftermarket keyboard builds. As with any keycap set, check compatibility with the specific keyboard model before ordering, particularly when the board has a compact or non-standard bottom row.

Frequently asked questions

How do I confirm that a keycap set is compatible with my keyboard?

Start by identifying the switch stem: remove one existing keycap and inspect the exposed post. A cross-shaped stem indicates Cherry MX-style compatibility, which covers most aftermarket keycap sets. Next, check the keyboard layout, whether ANSI or ISO, then measure the spacebar width, right Shift size, and bottom-row modifier widths in units. A 6.25u spacebar is the most common standard, but compact boards often use different modifier sizes that not every set includes. Matching the stem, layout, and key sizes provides a reliable guide to compatibility before purchase.

Is PBT or ABS better for everyday typing?

The difference comes down to what degrades first under daily use. PBT is denser and more resistant to surface shine, so high-use keys such as WASD and the spacebar retain their matte texture for longer. That is why community discussion often favours PBT for long-term everyday typing. ABS is lighter and available in a broader range of vivid colours, but sustained finger contact can make its surface glossy; this is a property of the material, not a defect. For most keyboard users who prioritise durability and a consistent texture, PBT is the stronger long-term choice. ABS suits those who value colour range and a lighter feel more than wear resistance.

Do keycap profiles affect typing comfort during long sessions?

Keycap profile height and top-surface shape both influence how fingers interact with a keyboard over time. Taller profiles such as SA, at approximately 16.5 mm, create a more pronounced typing surface that may require a wrist rest during extended sessions. Cherry profile, at approximately 9.4 mm, reduces finger extension per keypress, which many users find more comfortable for sustained productivity. Uniform profiles such as DSA, at 7.6 mm, provide a flat, low typing surface suited to ortholinear or custom layouts. Hand size, desk height, and posture also affect profile choice, so testing different profiles on the same keyboard is the most reliable approach when comfort during long typing sessions matters.