Keychron B3 Pro Ultra-Slim vs Keychron K5 SE
Keychron B3 Pro Ultra-Slim is the cheaper pick at $34.99, roughly 59% under Keychron K5 SE ($84.99). Keychron K5 SE offers more keys for full-layout workflows, while Keychron B3 Pro Ultra-Slim trims the footprint. The right pick comes down to which spec trade-offs fit your build — the pick-if grid below breaks that out in detail.
Detailed comparison
Spec-by-spec breakdown — differences highlighted in cyan.
| Spec | Keychron B3 Pro Ultra-Slim | Keychron K5 SE |
|---|---|---|
| Name | Keychron B3 Pro Ultra-Slim | Keychron K5 SE |
| Brand | Keychron | Keychron |
| Price range | $34.99 | $84.99 |
| Community score | — | — |
| Form factor | 75% | Full-size (100%) |
| Key count | 84 | 104 |
| Hot-swap | No | Yes |
| Supported switch pins | 3, 5 | 3, 5 |
| Case material | — | — |
| Plate material | — | — |
| Mounting style | — | — |
| Connectivity | Wired USB-C, Bluetooth (5.0+), 2.4GHz wireless (dongle) | Wired USB-C, Bluetooth (5.0+) |
| RGB lighting | No | Yes |
| Layouts supported | — | ISO DE |
| QMK support | No | — |
| VIA support | No | — |
| Weight (g) | — | — |
| Polling rate (Hz) | — | — |
Name
- Keychron B3 Pro Ultra-Slim
- Keychron B3 Pro Ultra-Slim
- Keychron K5 SE
- Keychron K5 SE
Brand
- Keychron B3 Pro Ultra-Slim
- Keychron
- Keychron K5 SE
- Keychron
Price range
- Keychron K5 SE
- $84.99
Community score
Form factor
- Keychron K5 SE
- Full-size (100%)
Key count
Hot-swap
Supported switch pins
- Keychron K5 SE
- 3, 5
Case material
Plate material
Mounting style
Connectivity
- Keychron B3 Pro Ultra-Slim
- Wired USB-C, Bluetooth (5.0+), 2.4GHz wireless (dongle)
- Keychron K5 SE
- Wired USB-C, Bluetooth (5.0+)
RGB lighting
Layouts supported
- Keychron K5 SE
- ISO DE
QMK support
VIA support
Weight (g)
Polling rate (Hz)
Which should you buy?
Keychron B3 Pro Ultra-Slim is the cheaper pick at $34.99, roughly 59% under Keychron K5 SE ($84.99). Keychron K5 SE offers more keys for full-layout workflows, while Keychron B3 Pro Ultra-Slim trims the footprint. The right pick comes down to which spec trade-offs fit your build — the pick-if grid below breaks that out in detail.
Pick Keychron B3 Pro Ultra-Slim if
From $34.99
- You want a 75% layout
- You're on a tighter budget
Pick Keychron K5 SE if
From $84.99
- You want a full-size (100%) layout
- You plan to swap switches without soldering
- You want per-key RGB lighting
Also compared
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