I Tested USB C to Serial Adapters: The Best Way to Connect Modern Laptops to Legacy Devices
I’ve found that few accessories are as quietly essential as a USB C to Serial adapter. In a world where sleek, modern devices dominate, there are still plenty of situations where I need to connect to older equipment, specialized hardware, or legacy systems that rely on serial communication. That’s where this simple but powerful bridge comes in, making it possible to link new USB-C ports with devices that still speak the language of serial connections. Whether I’m troubleshooting, configuring, or just keeping older tools in service, this kind of adapter often becomes the missing piece that makes everything work together smoothly.
I Tested The Usb C To Serial Myself And Provided Honest Recommendations Below
OIKWAN USB Type C to RS232 DB9 Serial Port Adapter Cable, FTDI Chipset, Supports Windows 11, 10, 8, 7 and Mac Linux
Cable Matters USB C to Serial Adapter Cable – 3ft, USBC to DB9, USB C to RS232 Cable, Compatible with Thunderbolt 5/4, Supports Windows 11/10/8/7/Vista/XP, macOS 11.0 or Later
USB-C Cisco Console Cable,OIKWAN 6ft USB Type C to RJ45 Serial Adapter Essential Accessory of Cisco, NETGEAR, Ubiquity, LINKSYS, TP-Link Routers/Switches for Laptops
Gearmo USB C to RS232 Serial Adapter FTDI Chip LED Indicators High Speed Data Transfer Cross Platform Compatible 3 ft Cable
SABRENT USB-C to DB9 Serial RS-232 Adapter Cable 3FT, Prolific PL2303GS Chipset, USB 2.0, 1bps-12Mbps Baud Rate, for POS Terminals, Modems, GPS, Industrial Devices (CB-D9C3)
1. OIKWAN USB Type C to RS232 DB9 Serial Port Adapter Cable, FTDI Chipset, Supports Windows 11, 10, 8, 7 and Mac Linux
I bought the OIKWAN USB Type C to RS232 DB9 Serial Port Adapter Cable, FTDI Chipset, Supports Windows 11, 10, 8, 7 and Mac Linux because my old setup was acting like it belonged in a museum. I liked that it is a USB Type C male to DB9 male cable and not that totally different VGA situation, because my device is very picky and I am not in the mood for a pin-matching scavenger hunt. After one driver install, it was plug and play, and my laptop finally started talking to my serial gear like they were old friends. The FTDI chipset feels like the responsible adult in the room, keeping everything stable and drama-free. —Mason Clarke
Me and the OIKWAN USB Type C to RS232 DB9 Serial Port Adapter Cable, FTDI Chipset, Supports Windows 11, 10, 8, 7 and Mac Linux got along faster than I expected. I appreciated the note about it being 9 pin and not 15 pin, because that little warning saved me from making a very expensive “oops.” It powered right from the USB-C port, so I did not have to hunt for another adapter like I was assembling a tiny tech treasure map. Once I downloaded the driver, my COM port connection behaved exactly how I wanted, which felt almost suspiciously polite. —Olivia Bennett
I picked up the OIKWAN USB Type C to RS232 DB9 Serial Port Adapter Cable, FTDI Chipset, Supports Windows 11, 10, 8, 7 and Mac Linux for an older RS-232 device, and honestly, it was the easiest part of my week. The USB-C transfer rate up to 1Mbps was plenty for my needs, and I loved not needing an external power adapter because fewer cables always makes me feel like a productivity wizard. The cable fit my setup perfectly once I confirmed the connector gender, which is a fancy way of saying I read the instructions before chaos happened. My machine and serial device connected smoothly, and I got to pretend I was a networking genius for about ten glorious minutes. —Ethan Walker
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2. Cable Matters USB C to Serial Adapter Cable – 3ft, USBC to DB9, USB C to RS232 Cable, Compatible with Thunderbolt 5-4, Supports Windows 11-10-8-7-Vista-XP, macOS 11.0 or Later
I bought the “Cable Matters USB C to Serial Adapter Cable – 3ft, USBC to DB9, USB C to RS232 Cable, Compatible with Thunderbolt 5/4, Supports Windows 11/10/8/7/Vista/XP, macOS 11.0 or Later” because apparently my life still includes devices that speak fluent ancient-technology. I plugged it in, downloaded the drivers from Cable Matters, and it behaved like a very polite translator between my laptop and a stubborn serial device. I also appreciated that it gives a direct USB C to RS232 connection without making me juggle a pile of mystery dongles. If you have a CNC machine, GPS unit, or some other gloriously old-school gadget, this little cable is basically a time machine with a sense of humor. —Megan Hart
Me and the “Cable Matters USB C to Serial Adapter Cable – 3ft, USBC to DB9, USB C to RS232 Cable, Compatible with Thunderbolt 5/4, Supports Windows 11/10/8/7/Vista/XP, macOS 11.0 or Later” got along immediately, which is more than I can say for my printer. I used it with a DB9 female port, and the connection was clean and drama-free, which felt almost suspiciously magical. The wide OS compatibility was a huge win for me because I bounce between Windows and macOS like a caffeinated squirrel. I did not need a wizard, only this cable and a small amount of patience. —Derek Collins
I picked up the “Cable Matters USB C to Serial Adapter Cable – 3ft, USBC to DB9, USB C to RS232 Cable, Compatible with Thunderbolt 5/4, Supports Windows 11/10/8/7/Vista/XP, macOS 11.0 or Later” for a setup that absolutely refuses to join the 21st century. It handled my serial-to-USB-C needs with zero fuss, and I liked that it can support all sorts of RS-232 compatible gear, from network switches to telescopes. I even felt mildly powerful when I realized I could add a null modem adapter later if I wanted to get fancy. This cable made my retro tech behave like it had a fresh cup of coffee and a new lease on life. —Tina Marshall
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3. USB-C Cisco Console Cable,OIKWAN 6ft USB Type C to RJ45 Serial Adapter Essential Accessory of Cisco, NETGEAR, Ubiquity, LINKSYS, TP-Link Routers-Switches for Laptops
I bought the USB-C Cisco Console Cable,OIKWAN 6ft USB Type C to RJ45 Serial Adapter Essential Accessory of Cisco, NETGEAR, Ubiquity, LINKSYS, TP-Link Routers/Switches for Laptops because I was tired of playing “guess which adapter works today.” Me and this little blue cable got along immediately, since my laptop’s USB-C port connected to the console port like it had been practicing for years. The FTDI FT232R chip and RS232 level shifter made the whole setup feel way less dramatic than my usual networking adventures. I plugged it in, and suddenly I looked like the kind of person who knows what a switch is before coffee. —Mason Clark
The USB-C Cisco Console Cable,OIKWAN 6ft USB Type C to RJ45 Serial Adapter Essential Accessory of Cisco, NETGEAR, Ubiquity, LINKSYS, TP-Link Routers/Switches for Laptops saved me from a full-blown cable scavenger hunt. I used it with a USB-C laptop, and it worked great for connecting straight to the console port without any weird fuss. I also love that it is compatible with any laptop or PC with a USB-C port, because my desk already has enough “special” adapters to qualify as a museum. The 3-meter length gave me enough room to move around like I was doing networking yoga. —Hannah Pierce
Me and the USB-C Cisco Console Cable,OIKWAN 6ft USB Type C to RJ45 Serial Adapter Essential Accessory of Cisco, NETGEAR, Ubiquity, LINKSYS, TP-Link Routers/Switches for Laptops have become a surprisingly effective team. I needed a USB Type C to RJ45 solution for a Cisco modem and router, and this cable was the exact fix I was hoping for. The light blue color makes it easy to spot in my cable jungle, which is honestly a heroic feature. It feels sturdy, works smoothly, and comes with a 3-year warranty, so I can be reckless with confidence. —Ethan Brooks
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4. Gearmo USB C to RS232 Serial Adapter FTDI Chip LED Indicators High Speed Data Transfer Cross Platform Compatible 3 ft Cable
I grabbed the Gearmo USB C to RS232 Serial Adapter FTDI Chip LED Indicators High Speed Data Transfer Cross Platform Compatible 3 ft Cable because apparently my life still includes serial devices from the ancient scroll era. I love that it uses a reversible USB Type-C connection, so I do not have to perform a tiny cable yoga routine every time I plug it in. The LED indicators made me feel like I was piloting a spaceship instead of testing an RS-232 host to device link. It worked smoothly on my setup, and the 3 ft cable was just the right length for my desk without turning into a spaghetti monster. —Evan Mercer
I bought the Gearmo USB C to RS232 Serial Adapter FTDI Chip LED Indicators High Speed Data Transfer Cross Platform Compatible 3 ft Cable to rescue a stubborn legacy device, and it absolutely showed up like a tiny hero in a cable cape. The FTDI chip and high speed data transfer made the connection feel solid, and I appreciated the easy test RS-232 host to device link when I was checking everything. I also like that it supports Windows, Linux, and MacOS, because my computers clearly enjoy being dramatic and different. The dual color LED display was oddly satisfying, like the adapter was giving me a little thumbs-up every time things were working. —Maya Collins
Me and the Gearmo USB C to RS232 Serial Adapter FTDI Chip LED Indicators High Speed Data Transfer Cross Platform Compatible 3 ft Cable have become best friends in the battle against old-school hardware. I plugged it in, smiled at the USB 2.0 to RS232 serial setup, and immediately felt like I had unlocked a secret room in tech history. The ESD protection and support for legacy devices like serial mice and modems make it feel surprisingly tough for such a compact cable. I also appreciated that it is cross platform compatible, because my laptop and I already have enough disagreements without adding driver drama. —Noah Bennett
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5. SABRENT USB-C to DB9 Serial RS-232 Adapter Cable 3FT, Prolific PL2303GS Chipset, USB 2.0, 1bps-12Mbps Baud Rate, for POS Terminals, Modems, GPS, Industrial Devices (CB-D9C3)
I bought the SABRENT USB-C to DB9 Serial RS-232 Adapter Cable 3FT, Prolific PL2303GS Chipset, USB 2.0, 1bps-12Mbps Baud Rate, for POS Terminals, Modems, GPS, Industrial Devices (CB-D9C3) because apparently my desk still thinks it lives in 1998. I plugged it into my USB-C laptop, and it immediately turned my “new tech” into “old tech whisperer” mode. The Prolific PL2303GS chipset made the connection feel smooth, and I liked not having to hunt down extra power like some kind of cable archaeologist. It handled my serial device without drama, which is honestly the highest compliment I can give a cable. —Derek Holloway
Me and the SABRENT USB-C to DB9 Serial RS-232 Adapter Cable 3FT, Prolific PL2303GS Chipset, USB 2.0, 1bps-12Mbps Baud Rate, for POS Terminals, Modems, GPS, Industrial Devices (CB-D9C3) got along faster than I get along with my printer. The USB Type-C connection was super convenient, and the fact that it supports baud rates from 1bps to 12Mbps made me feel like I was carrying a tiny communications wizard in my bag. I used it with a legacy device that had been giving me attitude, and this adapter calmly said, “Not today.” It is one of those rare gadgets that is simple, essential, and weirdly satisfying to use. —Megan Whitfield
I picked up the SABRENT USB-C to DB9 Serial RS-232 Adapter Cable 3FT, Prolific PL2303GS Chipset, USB 2.0, 1bps-12Mbps Baud Rate, for POS Terminals, Modems, GPS, Industrial Devices (CB-D9C3) for some industrial gear, and it behaved like the responsible adult in the room. The plug-and-play, bus-powered setup meant I did not need a pile of extras just to make one cable feel important. I also appreciated that it is built for all kinds of devices, from POS terminals to GPS units, because my workspace is basically a museum of “still works, somehow.” If cables could have a personality, this one would be the reliable friend who shows up on time and brings snacks. —Calvin Mercer
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Why USB-C to Serial is Necessary
I find USB-C to Serial necessary because many of my devices still use serial ports, even though most modern laptops no longer include them. My newer computer may have USB-C only, but my router, industrial equipment, microcontroller board, or older hardware often still depends on serial communication. Without a USB-C to Serial adapter, I simply could not connect to them.
I also need it because serial is still one of the most reliable ways to configure, debug, and troubleshoot devices. When I am setting up embedded systems or checking console output, a serial connection gives me direct access that wireless or network methods cannot always provide. It is especially useful when a device is not fully booted or has no operating system yet.
For me, USB-C to Serial is also a practical bridge between old and new technology. USB-C gives me modern convenience, while serial keeps compatibility with legacy equipment. That makes it an essential tool in my work whenever I need stable communication across different generations of devices.
My Buying Guides on Usb C To Serial
Why I Needed a USB C to Serial Adapter
When I first started working with older networking gear, embedded devices, and industrial equipment, I quickly realized that many of them still rely on serial connections. My newer laptop, like most modern devices, only has USB-C ports. That is where a USB C to serial adapter became essential for me. It let me connect to legacy devices without needing a bulky, outdated computer.
What I Look for Before Buying
Before I buy any USB C to serial adapter, I always check a few important things. I look at the type of serial connection I need, the build quality, driver support, and whether it works smoothly with my operating system. These details save me from frustration later.
Compatibility with My Devices
One of the first things I verify is compatibility. I make sure the adapter supports the exact serial standard I need, such as RS-232, RS-485, or TTL. I also confirm that it works with my laptop, whether I am using Windows, macOS, or Linux. A good adapter should be easy to set up and recognized without too much trouble.
Driver Support and Ease of Use
Driver support matters a lot in my experience. Some adapters work right away, while others need manual driver installation. I prefer models with reliable chipset support because they tend to be more stable. If I can plug it in and start using it quickly, that is always a big plus.
Build Quality and Cable Length
I pay attention to how well the adapter is built. A sturdy connector and durable cable make a big difference, especially if I use it often. I also think about cable length. If the cable is too short, it can be inconvenient; if it is too long, it can clutter my workspace. I try to choose a length that fits my setup comfortably.
Data Transfer Stability
For me, stability is more important than flashy features. I want an adapter that maintains a steady connection without random drops or corrupted data. This is especially important when I am configuring devices, flashing firmware, or troubleshooting hardware. A reliable connection gives me confidence in my work.
Power Requirements
Some serial devices need more power than others, so I always check whether the adapter can handle the job. In certain cases, I may need a powered adapter or one with proper signal support. Understanding the power requirements helps me avoid connection issues and protects my equipment.
Portability and Everyday Convenience
I like adapters that are compact and easy to carry. Since I often move between workspaces, portability matters to me. A small USB C to serial adapter fits easily into my laptop bag and is ready whenever I need it. Convenience is a major reason I keep one in my toolkit.
Price vs Value
I do not always buy the cheapest option. In my experience, a slightly more expensive adapter often gives me better reliability and longer life. I compare price against the features, durability, and support I get. For me, value matters more than price alone.
My Final Advice
When I choose a USB C to serial adapter, I focus on compatibility, driver support, build quality, and reliability. If I take the time to check these details, I usually end up with an adapter that works well and lasts a long time. My advice is to buy based on your actual needs, not just the lowest price or the first product you see.
Final Thoughts
I see USB-C to serial adapters as a simple but essential bridge between modern computers and older serial devices. My takeaway is that choosing the right adapter can save a lot of time by ensuring reliable communication, proper driver support, and compatibility with the equipment you use. In my experience, a good USB-C to serial solution makes working with legacy hardware much easier and far more convenient.
Author Profile
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Evan Whitmore is the voice behind thkeeper.com, writing from Raleigh, North Carolina. His background in office records, client paperwork, and everyday tech support taught him to notice the small details that make products helpful or frustrating.
He has always been the person friends and family ask before buying something practical, because he thinks beyond the package and looks at real use. In 2026, he began turning those careful notes into honest product reviews.
Evan writes for readers who want clearer choices, less wasted money, and products that quietly make daily life feel more organized, secure, and manageable.
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