Keychron · 96% (1800) · Version 2 from 2020
The K4 squeezes 100 keys, number pad included, into a 96% layout, which makes it about 6 cm narrower than Keychron's full-size K10. Version 1 came with Gateron or LK optical switches. Version 2 followed in 2020 with a Broadcom Bluetooth 5.1 chip, an inclined bottom frame, a caps lock light and a relocated Delete key, plus soldered or hot-swappable Gateron G Pro switches. Every version pairs with three devices, has a USB-C wired mode and runs on a 4000 mAh battery Keychron rates at up to 240 hours with the lights off. Mac and Windows keycaps come in the box, though Keychron notes Num Lock only works on Windows. Stock caps are ABS, and cases are plastic or plastic with an aluminum frame. Version 3 arrived in 2025 with QMK, Bluetooth 5.2, Keychron Super switches and PBT keycaps. The K4 Pro, Max and HE are separate keyboards.
Versions
Version 1 was sold with Gateron or LK optical switches. Version 2 brought a Broadcom Bluetooth 5.1 chip, an inclined frame, a caps lock light and a moved Delete key, with soldered or hot-swappable Gateron G Pro switches in plastic or aluminum frames, plus UK, German and Nordic ISO versions. Version 3 (2025) adds QMK, Bluetooth 5.2, Keychron Super switches and double-shot PBT keycaps. The K4 Pro, K4 Max, K4 HE and K4 Ultra 8K are different boards.
The ABS keycaps go shiny with use. An LK optical K4 won't take MX switches, and each switch type has its own firmware, so a board flashed with the wrong file may not work at all.
New to used keyboards? How to check a used keyboard covers chatter, stabilizers, keycap shine and the rest in detail.
Buying guide
We'd buy the K4B1 titled tested and working with Red switches at $51 delivered from a 100% seller, under the $75 median, though it wears aftermarket caps, so ask whether the stock set comes too. There are at least 73 for sale; complete used boards from US and Canadian sellers ask $41–90 delivered, open-box and new cards about $81–84, and Japan dealers $185–280. The K4 came soldered or hot-swap and with Gateron or LK optical switches, so believe hot-swap only when the title says it and ask for a photo of one switch with its cap off. Only Version 3 has QMK and PBT caps, so trust a version only from the title or the box, and ask for a keyboardtester.com video with the numpad and how many days a charge lasts with the backlight off. Skip the zero-feedback seller shipping from Israel.
$41.36est. delivered
The lowest delivered complete K4 at $41, shown with its box and cable, from a 100% seller in Canada. The title names no switch or version, so ask which it is and for a typing test with the numpad.
Keychron K4 Gaming, Productivity Mechanical Keyboard Bluetooth/Wired
$51.46est. delivered
Titled tested and working, a K4B1 with Red switches at $51 delivered from a 100% seller, under the $75 median. The photo shows aftermarket caps, so ask whether the stock set comes too.
Keychron K4 (K4B1) Mechanical Keyboard (Used) Tested Working. Red Switches
$73.39est. delivered
Titled tested, a K4C1 with an aluminum frame and Red switches, shown lit, at $73 delivered from a 100% seller. It's mid-band, so it's the one for paying a little more and asking fewer questions; still ask how long a charge lasts.
Keychron K4 K4C1 RGB Mechanical Keyboard Aluminum Wireless Red Switch Tested
Delivered prices include shipping as eBay quoted it to a US address on Oct 14, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 14, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Used$41.36est. delivered
$22.15 + $19.21 shipping
Buy It Now$22.15
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
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Good buy
Shown with its box and cable. Ships from Canada, no switch named.
Seller: rub.snart
100% positive
Used$51.46est. delivered
$35.00 + $16.46 shipping
Buy It Now$35.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
K4B1 titled tested and working, Red switches. Wears aftermarket caps.
Seller: mguerville2009
100% positive
Used$73.39est. delivered
$62.96 + $10.43 shipping
Buy It Now$62.96
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
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Good buy
K4C1 aluminum with Red switches, titled tested and shown lit.
Seller: the_bay_bricks
100% positive
Used$59.00est. delivered
$50.00 + $9.00 shipping
Buy It Now$50.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
Titled Version 2 with Brown switches and a white backlight.
Seller: noschad_0
100% positive
Used$61.55est. delivered
$35.14 + $26.41 shipping
Buy It Now$35.14
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
K4A1Z titled working, shown with its cable. Ships from Canada.
Seller: vendingfams
99.4% positive
Used$97.52est. delivered
$90.00 + $7.52 shipping
Buy It Now$90.00
Our take
Titled Version 2, never used. Photo looks like a stock shot, so ask for real ones.
Seller: veroecheve-0
100% positive
Used$80.00est. delivered
$50.00 + $30.00 shipping
Buy It Now$50.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Check the seller
Titled hot-swappable, Blue switches, US layout, shown with box and extras. Ships from Israel, zero feedback.
Seller: evgeniape
No feedback yet
Used$280.00est. delivered
$220.00 + $60.00 shipping
Buy It Now$220.00
Priced high
Version 3 with Super Brown switches, titled JP JIS. From Japan, about 3.8 times the median.
Seller: kesady
98.8% positive
Prices change daily. The live eBay search shows everything listed now, including anything new since Oct 14, 2026.
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