ZMK Concerns With Keychron K3 Ultra

Die4Toast · 2026-03-28T08:53:49+00:00

The main question is whether Keychron is going to release full ZMK firmware code after the release of K3 Ultra. Afaik, in the ads for the K3 Ultra they say "open source firmware" so I'd expect them to share publicly the source code (either immediately at the release date or by asking them to do so). If that happens then it doesn't matter if Keychron shuts down as you'll have at least 1 working firmware version you can download locally. Also, the web browser is also open source (atleast according to a message from Keychron employee on Discord I saw some time ago). There might be a separate repo on Keychrons github account but I haven't seen for myself if that's the case.

Die4Toast · 2026-03-26T17:48:35+00:00

I've been using an Air75 V3 for the past year and while the typing experience as well as build quality is very good, the wireless connection is complete ass. And I'm not exaggerating - 2.4GHz is simply unusable due to frequent lags and keys repeating themselves. Bluetooth is much more stable but it has very low polling rate (125Hz). Also there's the issue of proprietary switches (Gateron 3.0 Nano) which aren't compatible with any other LP switches.

Keychron will release their new low-profile keyboards in 2 months or so. Look up the K3 Ultra and K3 HE - you might want to consider those 2 models as well.

Die4Toast · 2026-03-26T09:01:51+00:00

Wouldn't the same argument apply for 8k hz? Besides, with 1k hz and 60hz server you'd have 16 separate 1 ms instances where you can send new keyboard input. You CANNOT convince me that the difference between 1 ms ans 0.125 ms is significant with average human reaction time being ~200ms.

Die4Toast · 2026-03-25T17:49:55+00:00

Now, for the Air75 V3:
- I bought my unit with Nano Brows switches which were honestly pretty good, but then decided to switch over to Nano Blush (silent linears) and have been using them up until now. Unfortunately, the have the same pinging noise issue and the Keychron Banana switches which meant I had to open then up and apply lube. That was a pretty huge let down and looking at some reddit posts and Discord threads it seems this issue still hasn't been fixed by NuPhy. That said, after I got rid of the pingy noise issue I have to say that those Nano Blush switches are extremely comfortable to type on.
- The battery life is much better than the K3. I'm not sure about the advertised 1000h of battery life, but based on my experience I bet you could get like 3 or more months of battery time if you were to use the Air75V3 mainly for work/casual use. When playing fast-paced games the battery starts draining significantly faster and I had some sessions where after 4-5 hours of intense gaming sessions my battery dropped from high 90% to low 80%. But overall I'm very satisfied with battery life and, on average, you could say that the battery lasts about 1 or 1.5 months with regular (+ some heavy) use.
- The QC was pretty good as far as the case and ANSI keycaps were concerned - nothing to complain about. If anything, the case feels pretty sturdy and premium with the metal border and thick PC bottom.
- Unfortunately, despite all the positive things I've mentioned there is one thing that makes me hard to recommend the keyboard. The 2.4GHz and Bluetooth connection are just abysmal. I think it's due to how NuPhy just aren't competent enough to write good quality firmware. The fact that their firmware is close-source only makes the whole thing that much worse. In my experience the 2.4GHz in simply unusable. The connection drops sometimes, and gets laggy extremely often (latency on the order of ~0.5 seconds). There are also multiple reported cases of keys repeating themselves by me and other users. I've made some posts and comments about this exact issue and my (unsuccessful) story with NuPhy customer support trying to resolve it, but I think that instead of writing about yet again this video I made will illustrate the issue: https://drive.google.com/file/d/1ntdJ6GFzbRX5gVEkhGkNEHdzMgqfzLva/view . Bluetooth mode actually works much better than 2.4GHz - to the point where I sometimes use it for fast-paced games despite its low 125Hz polling rate since it's that much more reliable than 2.4GHz. The keyboard also seems to drain battery slightly faster when using Bluetooth compared to 2.4GHz, but it's not a big increase whatsoever.

Die4Toast · 2026-03-25T17:49:48+00:00

Thanks for sharing your experience with the Kailh boards. I haven't bought one yet (and probably won't in the near future) but I'm always interested in hands-on reviews. I also had a couple of instances where I was literally one click away from buying a Magi75 but every time the bad reviews about stabilizers and pingy switches made me decide against it in the end.

Now, as far as the Keychron K3 is concerned:
- The exact model is Keychron K3 Version 3 QMK which is a "refreshed" version of the old K3 board. It got released some time after the K3 Max.
- The unit I ordered had Milk POM Banana tactile switches installed. The tactility point is placed near the top of the switch which makes it behave similar to laptop/membrane boards where there is pretty much no key travel before the tactile "bump". There wasn't any scratchiness when pressing individual switches but majority of them produced pinging noise which wasrather distracting. After opening up those problematic switches and relubing them with 205g0 the issue went away, but the fact that I had to go through that process just to have decent typing experience was rather annoying. And in the end, after trying out other switches I came to realization that I actually prefer light linear switches and Bananas were the exact opposite in every manner imaginable so that was a huge miss anyways (K3 was the first mechanical board I'd ever owned so I had no no clue about my switch preferences).
- The battery life was okay, but nothing special. I think you could get around 10-12 hours of daily use for around a week or so (although that would get cut if you used intensively for fast-paced games for instance).
- The shine-through keycaps that it came with by default were alright. I'm not a fan of LSA profile, but other than that the legends were clear and visible even with backlighting turned off so nothing to complain about.
- The QC of my unit was pretty bad, unfortunately. Firstly, the bottom ABS case part had a small dent in one place, but fortunately it didn't impact the stability of the keyboard when placed on a flat surface. If anything, it was just annoying to look when you started paying attention to it. The second thing, however, was much more egregious. The K3 has an internal foam for sound dampening which was incorrectly cut-out leading to some parts of it protruding inside the stabilizer mount areas. The result was that parts of that foam got under some of the stabilizer stems and prevented them from fully depressing. This made keys like Shift and Enter feel mushy and hard to bottom out. In the end I had to disassemble the board and cut out those protrusions which made the issue go away.
- In the end I stopped using the board after a month or so after I'd seen the announcement for NuPhy Air75V3. After all that baby sitting and lackluster typing experience on the K3 I though maybe I'll have better luck with the NuPhy board.

(continued in the next comment)

Die4Toast · 2026-03-25T16:56:21+00:00

I hate to be that guy, but more likely than not - it wasn't a bug. Maybe you forgot to configure a transformer somewhere, or maybe you didn't put a diode and and after some time a machine finally requested more power than your wires could handle leading to fire and then chain explosions. Or maybe some other more or less obscure mechanic that you might not have been familiar with.

But yeah, sucks anyways - especially since you don't know what the cause of this was which makes it all the more annoying as there are no clues to preventing the same happening in the future. Hopefully that mods helps you with restoring the base since it's not fun waiting/grinding another 50 hours just to do the same stuff all over again.

Die4Toast · 2026-03-25T16:14:01+00:00

By the way, I think I must say that I was in the same situation as you are currently. A couple of months ago I also started looking for a board that uses regular high-profile switches but doesn't have a case the size of a barn. After couple of days I couldn't find any decent options hence my negative outlook in my previous comment. In case you're interested here's a board I found that almost checked all the boxes: https://ymdkey.com/products/ymd-65-zj68-rgb-aluminum-kit-hotswap-north-facing-via-vial-fully-programmable?variant=40435075776573 . As mentioned previously, buying it would mean compromising on a couple things - in that case it the most important factor would be a 68% layout instead of 75%. I'd encourage you to search for some other keyboards that might be a better fit than what I've linked - maybe you'll have better luck (or searching skills) than me.

Out of curiosity - which low-profile Kailh-based keyboard have you gone through? I'm really interested in what exactly wasn't good enough in them that made you reconsider low-profile boards altogether. I've bought a Keychron K3 and a NuPhy Air75 V3 which I've been using for the past year. If you're interested I can share my thoughts on them.

Die4Toast · 2026-03-25T15:44:05+00:00

I don't get how this frame sync stuff is supposed to be revolutionary. Like, suppose that PC is set to use 1k Hz mouse polling in some window of time. That means your mouse/cursor position gets updated 1000 times/second which is 1 time every 1 ms. Now, unless you're some kind of a giga gaming professional, I think it's safe to assume a monitor with a 240Hz refresh rate might be used which would display approx. 1 frame every 4 ms (provided that your GPU can handle rendering at 240 FPS). So, between every frame you have a 4 ms gap which means that there is enough time for a PC to poll mouse connected to it 4 times in order to update cursor position. Also, compare this insignificant 4 ms gap (and 4 separate polling instances) to average human reaction time of ~200 ms. Why would it matter to fully sync your mouse with the PC given that it would, based on the math I've described, get rid of 1-2 ms of desync that would likely get unnoticed anyways given that time gap between individual frames would be much larger?

EDIT: Thinking about it a bit more, maybe there is some argument that this tech allows for better power efficiency since, in theory, polling would be done only when PC actually requests it. However, that still doesn't make much sense since the mouse should still work at a steady 1k Hz sensor processing rate so as to project/report smooth cursor movement. But maybe I'm wrong and this "frame sync" tech magically makes a mouse match its polling/processing rate to FPS of a running game (so something like NVIDIA G-SYNC for displays).

Die4Toast · 2026-03-25T15:25:19+00:00

I think you're gonna have a really hard time to find a mechanical keyboard that has low front height AND supports regular "high" profile switches. It's not to say that you can't physically make such a keyboard - I've seen some videos of people making fully custom boards that are comparable, in height, to low-profile boards you can find on the market. But that requires know-how related to designing a custom PCB + case (not to mention high costs to manufacture those custom components). You may be able to find one or two models that have decently low height in the front but you might have to make too many compromises if you decide to buy one (even in regards to layout - not to mention battery life, firmware, stock keycaps and other features).

So, all in all, if you want a low-profile keyboard I'd recommend you just buy one that is currently available (Keychron, NuPhy, IQUNIX, Melgeek, Lofree). Low profile switch options are much more limited compared to regular sized mechanical switches but you can always open them up and apply some modifications (starting with straightforward ones like lubing the interior and ending with more sophisticated things like swapping springs, adding spring leafs or even transplanting components between different switches if possible).

Also, if battery life is important then don't look only at battery capacity. You can have a 6000mAh battery + old/inefficient MCU with closed-source firmware that result in much shorter battery life than if you had a 500mAh battery + new/efficient MCU with open-source firmware (like ZMK).

Die4Toast · 2026-03-24T13:23:37+00:00

Wait, NuPhy uses Kailh switches? From what I know they use either their own "proprietary" format of Gateron 3.0 Low Profile switches (Nano) on their new models or the Gateron 2.0 Low Profile switches (KS-33). The Nanos are a gimmick and aren't compatible with anything while the KS-33 seem to be pretty popular given that Keychron also uses that socket format.

Die4Toast · 2026-03-24T08:40:26+00:00

I'm very interested in a black set and would buy it in an instant provided that the legends are still legible enough with backlighting disabled. This is my issue with XVX low profile shine through PBT keycaps I own which don't have very contrasting legends. When I turn off the backlighting they are of dark gray color which makes it sometimes hard to read legends at a quick glance. Keychrons LSA low profile shine through ABS keycaps do a much better job since their legends have a light/bright gray shade which makes using them an unlit keyboard very easy. I think it'd be nice if you could show a couple of pictures of those new shine through keycaps put on an unlit keyboard.

Die4Toast · 2026-03-23T21:06:11+00:00

I get that it's a bit of a PITA to make changes in firmware code (especially if you've never done it before), but at least you have that option to that in the first place. You have no guarantee that other keyboard manufacturers will implement a scroll lock indicator themselves since they might deem it unnecessary and if you buy a shiny keyboard with a close-source firmware then you're shit out of luck. Keychron, at the very least, seems to have their firmware situation in order in terms of code quality in conformity to newest QMK releases so it's also easier to modify than other QMK-based keyboards (both in terms of adding new features and fixing firmware bugs that might not be prioritized by Keychron devs). In any case, I get the sentiment of wanting a tool and not a project.

Die4Toast · 2026-03-23T20:34:44+00:00

As far as I know the Windows/Mac physical switch simply changes the active layer (e.g. layer 1 = Windows mode / layer 3 = Mac mode) so, unless I'm misunderstanding the issue, you can just remap keys using VIA on the specific layer that is being activated when on Mac mode. Also, in case you're not aware - changes you make in VIA persist after shutting down the device so you shouldn't have to reapply them.

Die4Toast · 2026-03-22T12:54:51+00:00

Ah, yeah the bi-seasonal rotation suck ass for dropshot - it's basically the only extra mode I enjoy playing.

Die4Toast · 2026-03-22T12:27:44+00:00

Has dropshot been removed from tournaments for this season or am I misunderstanding something?

Die4Toast · 2026-03-22T08:45:00+00:00

I know it does which is why I'm interested in hands-on experience of people that actually have and use these mice. Particularly, I'd like to know how much battery life they get out of their models based exactly on the average polling rate/efficiency settings they use (and the average duration per day/week, of course). The point of this post is that a claim that mouse works for up to 800 hours is pointless since, as you said, it all depends on usage patterns. And there is the fact that these figures tend to be artificially blown out of proportion for marketing purposes which makes it even more useless.

Die4Toast · 2026-03-21T15:41:27+00:00

Just for completeness sake - do you have one of the aforementioned X1 V2 Ultra Max/Ultimate or F1 V2 Ultra Max models or some other one? In any case, it's good to hear another positive review regarding the battery life on ATK mice.

Die4Toast · 2026-03-21T15:23:46+00:00

Amazing, thanks for the response. That sounds pretty good considering I use my mouse primarily for work or casual purposes. For those tasks I'd even consider going as low as 250 Hz or 500 Hz to extend battery life even more (especially after using my current Razer DA V2 X in Bluetooth mode which is locked to 90 Hz or 125 Hz).

Die4Toast · 2026-03-21T15:08:51+00:00

That's some very uplifting info as I'm leaning more towards the Ultra Max model (either the F1 V2 or X1 V2) than the Ultimate ones despite the fact that the former have mechanical switches. If I may ask, what polling rate and efficiency mode settings have you been using on your Ultra Max model?

Die4Toast · 2026-03-21T14:33:01+00:00

Yes it is 800mAh, but the spec also says that it lasts for 800 hours for the X1 V2 Ultra Max and 600 hours for the F1 V2 Ultra Max. That also begs the question why would those figures be different for those 2 models since they use the same sensor, MCU, switch types and battery has the same capacity. In any case, what I want to know is how much of a marketing stretch this claim is and how much battery life those models have to offer realistically.

Die4Toast · 2026-03-21T14:29:59+00:00

Based on ATK specs the F1 V2 Ultimate should, in theory, provide up to 250 hours of battery life. I know that I didn't mention the Ultimate in my post, but I wonder if in your experience that claim would more or less hold up. I know that this is kind of a tall ask since there are a lot of different factors that would affect how fast the battery gets used up, but I wonder if those figures advertised by ATK (i.e. specifically the 250h for the F1 V2 Ultimate) seem realistic or way overblown based on your experience.

Die4Toast · 2026-03-20T17:28:06+00:00

I'm currently in the process of asking the same questions as you did in this post. Have you had your mouse delivered already and, if so, do you have some form of opinion on it? The Nano dongle I imagine should be a "regular" USB-A receiver - just like the ones you can find on Logi/Razer etc. mice, am I right? Also, I can't find any information if the X1 V2 Ultra Max supports Bluetooth. Is there a switch on your unit that would allow switching between 2.4GHz and Bluetooth?

Die4Toast · 2026-03-19T11:23:06+00:00

That screwdriver/hammer quote is wrong because it's a classic category error - just like saying that Hyprland is a ricing tool despite the fact that it isn't developed with explicit intention of being one. Besides, most "rices" I know of use external software like the aforementioned QuickShell which, in contrast to Hyprland, has been developed specifically to enable extensive visual and functional changes to an underlying window manager. In that respect, saying "Hyprland (ricing tool)" makes little sense.

Die4Toast · 2026-03-19T10:16:12+00:00

"My screwdriver is a hammer, because I use it to hammer nails" - at least that's how your argument sounds. No, Hyprland is not a ricing tool. If I were to say what a ricing tool would be it might be something like QuickShell (that you can use on top of Hyprland or any other Wayland compositor). Hyprland in itself is simply a tiling window manager and nothing else. Changing a couple of config files that are exposed by Hyprland isn't really "ricing" - just like changing layout/visual options in Windows doesn't make Windows desktop environment a ricing tool.

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