4 ms·

WhatCable: Know what your USB-C cable can do

110 points by mikecarlton 2mo ago

pogue 2mo ago
Is there something like this for Windows/Linux?
- delecti 2mo ago
  There are options on Linux that you can google up (I don't know enough about any of them to endorse them by linking to one in particular). As I understand it, Windows doesn't expose the necessary low-level hardware information for something like this to be possible.
- anticorporate 2mo ago
  I came here to ask the same thing. I did find a Linux tool with the same name and purpose but that seems to be an entirely different codebase: https://github.com/nedrichards/whatcable-linux https://github.com/nedrichards/whatcable-linux I have a handful of wireless keyboards that just absolutely refuse to negotiate for charging with certain cables at all, so I'm hoping this will help me at least figure out what those keyboards are looking for in terms of cable.
  - deleted 2mo ago
    [deleted]
- haunter 2mo ago
  "This is a Linux-native reimplementation inspired by darrylmorley/whatcable" https://github.com/nedrichards/whatcable-linux https://github.com/nedrichards/whatcable-linux But (hazard guess) it comes with a headless CLI binary (no GUI libraries needed) so probably could be ported to Linux (easily with an LLM?) https://github.com/darrylmorley/whatcable https://github.com/darrylmorley/whatcable
  - VorpalWay 2mo ago
    There is also https://github.com/Zetaphor/whatcable-linux https://github.com/Zetaphor/whatcable-linux (if you want a KDE UI rather than Gnome) and https://github.com/vzaliva/whatcable-linux-cli https://github.com/vzaliva/whatcable-linux-cli (a fork of the KDE repo, but only leaves the CLI tool).
    - notpushkin 2mo ago
      WhatKable was right there!
- duttish 2mo ago
  A quick search found https://github.com/nedrichards/whatcable-linux https://github.com/nedrichards/whatcable-linux, haven't tried it myself though
- nedrichards 2mo ago
  ChromeOS firmware has a bunch of this built in - it's super cool. https://nelsonslog.wordpress.com/2026/01/05/chromebooks-identify-usb-c-details/ https://nelsonslog.wordpress.com/2026/01/05/chromebooks-iden... and https://www.reddit.com/r/UsbCHardware/comments/1pyojjd/comment/nwknhii/ https://www.reddit.com/r/UsbCHardware/comments/1pyojjd/comme... and https://chromium.googlesource.com/chromiumos/platform2/+/HEAD/typecd/README.md https://chromium.googlesource.com/chromiumos/platform2/+/HEA... is where I found out about it. A lot of the clever capabilities rely on the firmware that you have. Source - having spent a while a few weeks back getting Codex to poke at this topic on my machine https://github.com/nedrichards/whatcable-linux/blob/main/docs/framework-13-usb-c-investigation.md https://github.com/nedrichards/whatcable-linux/blob/main/doc... since framework do reuse parts of the ChromeOS Embedded Controller in their firmware.
- SweetSoftPillow 2mo ago
  Check this for more details on Windows (original author's repo) https://github.com/darrylmorley/whatcable-windows https://github.com/darrylmorley/whatcable-windows
bestouff 2mo ago
I'm using the hardware tester from Treedix in which you have to plug both ends of the cable and which tests a lot of things, I'm quite fond of it. I have a basket with a lot of USB-c cables and without the tester I can't remember (nor guess) which one does what.
- blightful 2mo ago
  Nice. You just got them a sale from me. I have a crap ton of cables so this will come in handy.
  - bestouff 2mo ago
    Exactly my use case. And I have nothing to gain from that sale.
- callumprentice 2mo ago
  Would this tell me if a cable is close to the end of it's life? I like to travel light and I've had cables (mostly phone/pad power) go out on trips after working as expected when I packed.
  - cinntaile 2mo ago
    I think you would need something that tracks relevant per cable metrics over time to see if it is degrading. That one just says yes/no, but maybe yes/no starts to flicker around its end of life?
    - callumprentice 2mo ago
      Nod - that's what I was thinking. I expect it's often the connectors that deteriorate so perhaps moving them around while plugged in would tell me. Seems like a useful tool to have around.
      - kbouck 2mo ago
        i've used a treedix tester like this. the edition with many led lights, not the one with a screen. wiggle the cables around to see if and when any of the lights flicker, indicating a bad or broken connection. i've found a few bad cables that would intermittently fail.
lxgr 2mo ago
Great utility. The only wrinkles for me are that Macs apparently don't interrogate cables when they don't have to, i.e., when the power adapter supplies <= 60W (not sure if that's a USB-C protocol or an Apple implementation limitation) and that the website copy is full of GPT-isms, which makes me suspect that some of the output might be assumed instead of empirically validated as well.
robot_jesus 2mo ago
I'm curious if this also works for USB-A to USB-C. The use case: My Suburu has USB-A inputs and only allows wired Carplay. When I upgraded my iPhone and ditched Lightning, I had to try 6 different cables from my cable drawer to find one that supported data transfer. I have so many cables I've accumulated over the years, I should either purge or at least categorize the functionality of each.
- netsharc 2mo ago
  This adapter works with my Android phone and makes my Android Auto wireless: https://aliexpress.com/item/1005008214786824.html https://aliexpress.com/item/1005008214786824.html But it is the second product I tried; the first one didn't work (it's a 2020 Stellantis car). So, YMMV.
- jorts 2mo ago
  I'd recommend a wireless CarPlay adapter. I bought one for my car, and it's a game-changer.
  - gwbas1c 2mo ago
    I used to use one for Android. It worked for about 6 weeks, then stopped working, then a few months later I tried it and it worked for about 6 weeks before stopping working again!
- reasonabl_human 2mo ago
  I see other folks provided options, in case you want to avoid aliexpress, this one worked for me for the past 4 years https://a.co/d/0d9EOGRW https://a.co/d/0d9EOGRW Does require a bit of setup, can scan reviews to see if people have optimized a config for your specific vehicle
- kccqzy 2mo ago
  For cheap cables like USB-A to USB-C, I just throw away all cables that do not support data transfer. I don’t need the mental overhead of categorizing these cables. So any USB-A to USB-C cable in my cable drawer would work in this scenario. And CarPlay doesn’t even require USB 3.0; 2.0 is enough.
extinctLizard 2mo ago
Small question: did anybody succeed to pay via Apple Pay?
pdpi 2mo ago
I literally spent more than an hour yesterday debugging issues with USB-C cables that I wasn't aware were charging only, and this shows up today... Better late than never, I suppose, and definitely worth my ten quid.
- lxgr 2mo ago
  If you can afford it, I'd honestly throw these out. "Charging only" is not a spec-compliant thing in USB-C, and personally I wouldn't want to re-discover which devices do and don't support them every time I just want to quickly grab a cable. What's less easy to replace are all these damn USB-C devices lacking the UFP-identifying circuitry that only work on USB-A chargers using A-to-C cables...
  - pdpi 2mo ago
    To be clear, they're not literally "charging only", AIUI they're spec-compliant cables with USB2.0 480Mbps and power delivery, and they're allowed to not have the four SuperSpeed wire pairs. They're still useful for low bandwidth devices (like charging my keyboard/mouse). Incidentally — I spent an inordinate amount of time searching for USB3.2 cables on Amazon, and the vast majority of cables were actually just USB2.0 cables with PD support, and not actual Full-Featured cables.
    - lxgr 2mo ago
      Ah, I love these as they're generally much thinner/lighter/more flexible than USB-C 3 cables but still support at least 60W power delivery! Advertising them as USB 3 is a shame, though.
    - ssl-3 2mo ago
      Amazon's search is awful and I do not recall a time when it was better. It's probably this way by design, so that it always tends to present a never-ending stream of products to buy. But over here in the real world where I need a specific sort of USB 3.2 widget: Either the USB 3.2 widget exists, or it does not exist. Presenting pages and pages of not-results that were already explicitly defined as irrelevant do not help a person to spend money. :) (eBay's advanced search mode seems to still get it close-enough to right when rote specificity is important. I use it all the time to find very particular things.)
nerdsniper 2mo ago
Something that keeps needing to be pointed out every thread this stuff appears on: What these tools report are not functionally different from just believing "what's on the packaging", despite the misleading marketing claims. These tools read a chip called an "eMarker". These eMarkers are programmed to say whatever the manufacturer wants them to say - there's no requirement that the information be based in reality. Plenty of cables have eMarkers that claim "40Gbps" or whatever speeds, or support 240W PD...but absolutely cannot deliver either of those. And none of these consumer level software or hardware testers can actually test either of those claims. They can only take the cable's own claims at face value. Resistance measurements can cursorily test claims of 240W but resistance changes with temperature which changes with current...so unless your tester puts 5 amps down the wire for 5 minutes and then tests resistance it's not a very good test. AFAIK none of the testers flow 5 amps through the cable. Actual maximum data throughput is very hard to know. The only way to really "know" how much data can flow through a cable is with an expensive oscilloscope or cable tester. Because 80Gbps cables run at ~13GHz, at minimum you need a 26GHz scope (Nyquist–Shannon sampling theorem) or more practically a 52GHz scope. And it turns out it's really expensive to measure electrical signals 52 billion times per second. The necessary devices start at $15,000 (cable signal integrity tester) [0] on the very low end and only work for max 10Gbps USB 3.2 cables, or past $270,000 for 80Gbps USB4 cables (proper 60GHz oscilloscope) [1]. On the high end, each signal integrity test device can actually cost $1-2 million [2] where the base unit starts at $670,000 plus then spending additional money for hardware-accelerated analysis, specialized active probes, and the specific PAM-3 / USB4 compliance software packages. 0: https://www.totalphase.com/products/advanced-cable-tester-v2/ https://www.totalphase.com/products/advanced-cable-tester-v2... 1: https://www.edn.com/12-bit-oscilloscope-operates-up-to-65-ghz/ https://www.edn.com/12-bit-oscilloscope-operates-up-to-65-gh... 2: https://www.eevblog.com/forum/testgear/uxr1104a-infiniium-uxr-series-oscilloscope-110-ghz-4-channels-price/msg1839848/#msg1839848 https://www.eevblog.com/forum/testgear/uxr1104a-infiniium-ux...
- vel0city 2mo ago
  While I totally agree if you want to truly know the quality of the signal you need a very expensive box to actually measure the tiny deviations, if the question is "can this thing handle 80Gbit of data", can't you just get a couple of USB4 chips or whatever and have one send a pattern at that throughput and have the other try and receive and confirm that pattern? That would give you a basic "yes/no" kind of answer of "can it send XGbit?" I agree the processing capacity for such a thing at retail isn't likely to be $40, but probably a good bit less than >$15k. After all, you can get <$1,000 laptops that can do that pretty easily. For example, I don't need to precisely measure exactly how messed up the signal is to know if the HDMI cable works or not at a given resolution. I'll see the TV have issues displaying a picture. Either the picture is there reliably or its not. I'm not trying to fine tune the cable, I'm just trying to see if it generally works or not. As for testing power delivery, its not that electrically complicated to put a few amps through a wire for a few minutes. That said, the user must be aware if the cable isn't up to the standards that the chip states you could have some serious issues on your hands, but I guess better to find out on the tester at the workbench or desk than at your bedside.
amelius 2mo ago
Give me the freakin bit error rate please.
jwr 2mo ago
What would be really interesting is if I could connect a cable to two ports on a Mac and have the Mac test the cable.
- traceroute66 2mo ago
  > What would be really interesting is if I could connect a cable to two ports on a Mac and have the Mac test the cable. Not reproducible and introduces all sorts of other random variables to your test (buffering etc.).

110 points by mikecarlton 2mo ago

pogue 2mo ago

Is there something like this for Windows/Linux?

delecti 2mo ago
There are options on Linux that you can google up (I don't know enough about any of them to endorse them by linking to one in particular). As I understand it, Windows doesn't expose the necessary low-level hardware information for something like this to be possible.
anticorporate 2mo ago
I came here to ask the same thing. I did find a Linux tool with the same name and purpose but that seems to be an entirely different codebase: https://github.com/nedrichards/whatcable-linux https://github.com/nedrichards/whatcable-linux I have a handful of wireless keyboards that just absolutely refuse to negotiate for charging with certain cables at all, so I'm hoping this will help me at least figure out what those keyboards are looking for in terms of cable.
- deleted 2mo ago
  [deleted]
haunter 2mo ago
"This is a Linux-native reimplementation inspired by darrylmorley/whatcable" https://github.com/nedrichards/whatcable-linux https://github.com/nedrichards/whatcable-linux But (hazard guess) it comes with a headless CLI binary (no GUI libraries needed) so probably could be ported to Linux (easily with an LLM?) https://github.com/darrylmorley/whatcable https://github.com/darrylmorley/whatcable
- VorpalWay 2mo ago
  There is also https://github.com/Zetaphor/whatcable-linux https://github.com/Zetaphor/whatcable-linux (if you want a KDE UI rather than Gnome) and https://github.com/vzaliva/whatcable-linux-cli https://github.com/vzaliva/whatcable-linux-cli (a fork of the KDE repo, but only leaves the CLI tool).
  - notpushkin 2mo ago
    WhatKable was right there!
duttish 2mo ago
A quick search found https://github.com/nedrichards/whatcable-linux https://github.com/nedrichards/whatcable-linux, haven't tried it myself though
nedrichards 2mo ago
ChromeOS firmware has a bunch of this built in - it's super cool. https://nelsonslog.wordpress.com/2026/01/05/chromebooks-identify-usb-c-details/ https://nelsonslog.wordpress.com/2026/01/05/chromebooks-iden... and https://www.reddit.com/r/UsbCHardware/comments/1pyojjd/comment/nwknhii/ https://www.reddit.com/r/UsbCHardware/comments/1pyojjd/comme... and https://chromium.googlesource.com/chromiumos/platform2/+/HEAD/typecd/README.md https://chromium.googlesource.com/chromiumos/platform2/+/HEA... is where I found out about it. A lot of the clever capabilities rely on the firmware that you have. Source - having spent a while a few weeks back getting Codex to poke at this topic on my machine https://github.com/nedrichards/whatcable-linux/blob/main/docs/framework-13-usb-c-investigation.md https://github.com/nedrichards/whatcable-linux/blob/main/doc... since framework do reuse parts of the ChromeOS Embedded Controller in their firmware.
SweetSoftPillow 2mo ago
Check this for more details on Windows (original author's repo) https://github.com/darrylmorley/whatcable-windows https://github.com/darrylmorley/whatcable-windows

bestouff 2mo ago

I'm using the hardware tester from Treedix in which you have to plug both ends of the cable and which tests a lot of things, I'm quite fond of it. I have a basket with a lot of USB-c cables and without the tester I can't remember (nor guess) which one does what.

blightful 2mo ago
Nice. You just got them a sale from me. I have a crap ton of cables so this will come in handy.
- bestouff 2mo ago
  Exactly my use case. And I have nothing to gain from that sale.
callumprentice 2mo ago
Would this tell me if a cable is close to the end of it's life? I like to travel light and I've had cables (mostly phone/pad power) go out on trips after working as expected when I packed.
- cinntaile 2mo ago
  I think you would need something that tracks relevant per cable metrics over time to see if it is degrading. That one just says yes/no, but maybe yes/no starts to flicker around its end of life?
  - callumprentice 2mo ago
    Nod - that's what I was thinking. I expect it's often the connectors that deteriorate so perhaps moving them around while plugged in would tell me. Seems like a useful tool to have around.
    - kbouck 2mo ago
      i've used a treedix tester like this. the edition with many led lights, not the one with a screen. wiggle the cables around to see if and when any of the lights flicker, indicating a bad or broken connection. i've found a few bad cables that would intermittently fail.

lxgr 2mo ago

Great utility. The only wrinkles for me are that Macs apparently don't interrogate cables when they don't have to, i.e., when the power adapter supplies <= 60W (not sure if that's a USB-C protocol or an Apple implementation limitation) and that the website copy is full of GPT-isms, which makes me suspect that some of the output might be assumed instead of empirically validated as well.

robot_jesus 2mo ago

I'm curious if this also works for USB-A to USB-C. The use case: My Suburu has USB-A inputs and only allows wired Carplay. When I upgraded my iPhone and ditched Lightning, I had to try 6 different cables from my cable drawer to find one that supported data transfer. I have so many cables I've accumulated over the years, I should either purge or at least categorize the functionality of each.

netsharc 2mo ago
This adapter works with my Android phone and makes my Android Auto wireless: https://aliexpress.com/item/1005008214786824.html https://aliexpress.com/item/1005008214786824.html But it is the second product I tried; the first one didn't work (it's a 2020 Stellantis car). So, YMMV.
jorts 2mo ago
I'd recommend a wireless CarPlay adapter. I bought one for my car, and it's a game-changer.
- gwbas1c 2mo ago
  I used to use one for Android. It worked for about 6 weeks, then stopped working, then a few months later I tried it and it worked for about 6 weeks before stopping working again!
reasonabl_human 2mo ago
I see other folks provided options, in case you want to avoid aliexpress, this one worked for me for the past 4 years https://a.co/d/0d9EOGRW https://a.co/d/0d9EOGRW Does require a bit of setup, can scan reviews to see if people have optimized a config for your specific vehicle
kccqzy 2mo ago
For cheap cables like USB-A to USB-C, I just throw away all cables that do not support data transfer. I don’t need the mental overhead of categorizing these cables. So any USB-A to USB-C cable in my cable drawer would work in this scenario. And CarPlay doesn’t even require USB 3.0; 2.0 is enough.

extinctLizard 2mo ago

Small question: did anybody succeed to pay via Apple Pay?

pdpi 2mo ago

I literally spent more than an hour yesterday debugging issues with USB-C cables that I wasn't aware were charging only, and this shows up today... Better late than never, I suppose, and definitely worth my ten quid.

lxgr 2mo ago
If you can afford it, I'd honestly throw these out. "Charging only" is not a spec-compliant thing in USB-C, and personally I wouldn't want to re-discover which devices do and don't support them every time I just want to quickly grab a cable. What's less easy to replace are all these damn USB-C devices lacking the UFP-identifying circuitry that only work on USB-A chargers using A-to-C cables...
- pdpi 2mo ago
  To be clear, they're not literally "charging only", AIUI they're spec-compliant cables with USB2.0 480Mbps and power delivery, and they're allowed to not have the four SuperSpeed wire pairs. They're still useful for low bandwidth devices (like charging my keyboard/mouse). Incidentally — I spent an inordinate amount of time searching for USB3.2 cables on Amazon, and the vast majority of cables were actually just USB2.0 cables with PD support, and not actual Full-Featured cables.
  - lxgr 2mo ago
    Ah, I love these as they're generally much thinner/lighter/more flexible than USB-C 3 cables but still support at least 60W power delivery! Advertising them as USB 3 is a shame, though.
  - ssl-3 2mo ago
    Amazon's search is awful and I do not recall a time when it was better. It's probably this way by design, so that it always tends to present a never-ending stream of products to buy. But over here in the real world where I need a specific sort of USB 3.2 widget: Either the USB 3.2 widget exists, or it does not exist. Presenting pages and pages of not-results that were already explicitly defined as irrelevant do not help a person to spend money. :) (eBay's advanced search mode seems to still get it close-enough to right when rote specificity is important. I use it all the time to find very particular things.)

nerdsniper 2mo ago

Something that keeps needing to be pointed out every thread this stuff appears on: What these tools report are not functionally different from just believing "what's on the packaging", despite the misleading marketing claims. These tools read a chip called an "eMarker". These eMarkers are programmed to say whatever the manufacturer wants them to say - there's no requirement that the information be based in reality. Plenty of cables have eMarkers that claim "40Gbps" or whatever speeds, or support 240W PD...but absolutely cannot deliver either of those. And none of these consumer level software or hardware testers can actually test either of those claims. They can only take the cable's own claims at face value. Resistance measurements can cursorily test claims of 240W but resistance changes with temperature which changes with current...so unless your tester puts 5 amps down the wire for 5 minutes and then tests resistance it's not a very good test. AFAIK none of the testers flow 5 amps through the cable. Actual maximum data throughput is very hard to know. The only way to really "know" how much data can flow through a cable is with an expensive oscilloscope or cable tester. Because 80Gbps cables run at ~13GHz, at minimum you need a 26GHz scope (Nyquist–Shannon sampling theorem) or more practically a 52GHz scope. And it turns out it's really expensive to measure electrical signals 52 billion times per second. The necessary devices start at $15,000 (cable signal integrity tester) [0] on the very low end and only work for max 10Gbps USB 3.2 cables, or past $270,000 for 80Gbps USB4 cables (proper 60GHz oscilloscope) [1]. On the high end, each signal integrity test device can actually cost $1-2 million [2] where the base unit starts at $670,000 plus then spending additional money for hardware-accelerated analysis, specialized active probes, and the specific PAM-3 / USB4 compliance software packages. 0: https://www.totalphase.com/products/advanced-cable-tester-v2/ https://www.totalphase.com/products/advanced-cable-tester-v2... 1: https://www.edn.com/12-bit-oscilloscope-operates-up-to-65-ghz/ https://www.edn.com/12-bit-oscilloscope-operates-up-to-65-gh... 2: https://www.eevblog.com/forum/testgear/uxr1104a-infiniium-uxr-series-oscilloscope-110-ghz-4-channels-price/msg1839848/#msg1839848 https://www.eevblog.com/forum/testgear/uxr1104a-infiniium-ux...

vel0city 2mo ago
While I totally agree if you want to truly know the quality of the signal you need a very expensive box to actually measure the tiny deviations, if the question is "can this thing handle 80Gbit of data", can't you just get a couple of USB4 chips or whatever and have one send a pattern at that throughput and have the other try and receive and confirm that pattern? That would give you a basic "yes/no" kind of answer of "can it send XGbit?" I agree the processing capacity for such a thing at retail isn't likely to be $40, but probably a good bit less than >$15k. After all, you can get <$1,000 laptops that can do that pretty easily. For example, I don't need to precisely measure exactly how messed up the signal is to know if the HDMI cable works or not at a given resolution. I'll see the TV have issues displaying a picture. Either the picture is there reliably or its not. I'm not trying to fine tune the cable, I'm just trying to see if it generally works or not. As for testing power delivery, its not that electrically complicated to put a few amps through a wire for a few minutes. That said, the user must be aware if the cable isn't up to the standards that the chip states you could have some serious issues on your hands, but I guess better to find out on the tester at the workbench or desk than at your bedside.

amelius 2mo ago

Give me the freakin bit error rate please.

jwr 2mo ago

What would be really interesting is if I could connect a cable to two ports on a Mac and have the Mac test the cable.

traceroute66 2mo ago
> What would be really interesting is if I could connect a cable to two ports on a Mac and have the Mac test the cable. Not reproducible and introduces all sorts of other random variables to your test (buffering etc.).