4 Best USB to Serial (RS-232) Adapters [2023]

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In the realm of tech, it sometimes feels like we’re caught in a generational tug-of-war. On one side, you have your battle-tested legacy devices, and on the other, your shiny new computers.

Enter the USB to Serial (RS-232) adapter. Particularly in sectors like factory automation and telecommunications, this little gadget ensures that your old and new equipment work together seamlessly.

With so many of these adapters out there, picking the best one can feel overwhelming. We know how time-consuming it can be trying to research all your options.

So we sifted through them and chose four awesome adapters that really stand out. Our guide gives you the lowdown on each one. Here’s a quick peek at our top picks:

Product NameTransfer RateCompatibilityPower SourceUnique Features
DriverGeniusUp to 921.6 KbpsWindows, macOS, LinuxUSB9-LED activity monitoring, retains COM port values
GearmoN/AWindows (7 to 11), MacOS 10.X, LinuxUSBLED activity monitoring, full RS-232 signal support
Cable MattersUp to 225 KbpsWindows (2000 to 10), MacOS 10.6+, LinuxUSB (Bus-powered)Sleek design, lightweight
USBGearUp to 921.6 KbpsNot SpecifiedUSB10KV surge protection, flexible COM port assignment

While each adapter brings something unique to the table, they all provide superior connectivity for the aging RS-232. Let’s further explore our top picks so that you can confidently purchase the right one for your needs.

DriverGenius Professional USB-A and USB-C to RS-232 Adapter

DriverGenius Professional USB-A and USB-C to RS-232 Adapter

Key Takeaways:

  • 9-LED activity monitoring system
  • Fast transfers (921.6 Kbps)
  • Wide OS compatibility
  • Retains COM port values (USB232A-E-C)
  • Simplified power through USB

Designed for seamless RS-232 device connectivity, the DriverGenius Professional USB-A and USB-C to RS-232 Adapter steps in as the adept successor to the USB232A-B.

Tailored to meet the diverse needs of sectors like industrial automation, telecommunications, and IT, this device offers more than just a connection – it offers reliability. Its main attraction is undeniably the LED Activity Monitoring System, armed with 9 distinct LEDs. This feature is both aesthetic and functional, granting users a clear, visual representation of each specific signal pin’s status.


This proactive system simplifies diagnosing any potential hiccups in communication. Performance isn’t just a buzzword with the USB232A-E. With transfer rates peaking at 921.6 Kbps, it guarantees swift interactions with RS-232 devices, ranging from Modems to Barcode Scanners. Its cross-platform compatibility spanning Windows, macOS, and Linux makes it a versatile tool. Lightweight and devoid of unnecessary bulk, its portability is its silent strength.

Drawing power directly from the USB port, it foregoes the complexity of additional power sources. Switching gears to its USB-C counterpart, the USB232A-E-C, we see a device tailored for today’s USB-C-equipped gadgets. Sharing the signature 9-LED monitoring system, this adapter becomes indispensable to professionals like programmers and engineers. What’s really cool about it is that it remembers your settings.


So if you disconnect and then plug it back in or even move it to a different USB port, it’ll still recall your previous settings. That’s handy. It means less fiddling around and faster setup. Plus, whether you’re on Windows, Linux, or macOS, you’re covered in compatibility.

Being able to connect older devices with newer USB-C ones makes it a must-have for many professionals. The adapter champions convenience. Whether it’s about keeping the workflow efficient or ensuring device compatibility, the USB232A-E-C strikes the right balance.

Gearmo USB to Serial RS-232 Adapter

Gearmo USB to Serial RS-232 Adapter

Key Takeaways:

  • Compact and lightweight design
  • Comprehensive OS support
  • LED activity monitoring
  • Full RS-232 signal support
  • LED orientation can be tricky

Modern computers have been swiftly phasing out the beloved RS-232 serial port, which a bunch of gadgets and gear still depend on. Think ham radios, PDAs, thermal printers, and weather stations. This is where Gearmo’s USB to Serial RS-232 Adapter steps in.


Housed in a sleek blue design, it measures a compact 5.5 x 3.5 x 0.6 inches and weighs a mere 2.72 ounces. Its function is straightforward: seamlessly bridging the divide between old and new by connecting legacy DB-9 serial communications devices to current-gen USB-equipped machines.

The LED activity monitor on this adapter is a useful feature that indicates your connection status through distinctive flashes. This way, you can easily confirm that data transfer is going smoothly. But the functionality doesn’t stop there. The adapter comprehensively covers RS-232 signals, ensuring compatibility across a broad range of devices. It’s also quite accommodating when it comes to operating systems, supporting Windows versions from 7 to 11, MacOS 10.X, and Linux.


Simply plug it in, and you’re good to go. However, there’s room for improvement regarding the LED display. When you plug it into most devices, the LEDs are oriented downward, making the display somewhat difficult to see.

What really rounds out this product’s appeal is Gearmo’s longstanding reputation for reliability and quality in the tech industry. With over two decades in the business and a commitment to transparency, they offer easily accessible CAD files, mechanical drawings, and data sheets for this adapter.

Cable Matters USB to Serial Adapter Cable

Cable Matters USB to Serial Adapter Cable

Key Takeaways:

  • Bus-powered for plug-and-play
  • Compatible with Windows, MacOS, Linux
  • Compact and lightweight
  • Supports up to 225 Kbps transfer
  • Some systems might not detect cable

If you’re on the hunt for a reliable and efficient USB to RS232 adapter, Cable Matters has a strong contender. Their USB to Serial Adapter Cable simplifies the connection process, allowing a computer’s USB-A port to link up with a device having a female DB9 port. One of the key features of this device is its bus-powered design, which means no external power source is necessary – simply plug and play.

The device comes in a sleek black color and possesses a male-to-male connection, ideal for interfacing with equipment that demands a DB9 connector. If you happen to face compatibility issues with the DB9 port, solutions like a DB9 mini gender changer can help, although it’s sold separately. There’s also a provision to connect a null modem adapter, which can be of assistance if you’re aiming to directly link two computers via serial cables.


One of the stellar highlights of this unit is its compatibility. Whether you’re using Windows (ranging from Windows 2000 up to Windows 10) or MacOS 10.6 and above, this adapter ensures a seamless connection. However, if you’re a Linux user, the device supports kernels from 2.4.31 and later. The adapter weighs a mere 1.44 ounces. Combined with its dimensions of 3.54 x 2.76 x 0.31 inches, it’s incredibly portable.

Performance-wise, expect a data transfer rate that can reach up to 225 Kbps. While drivers for the PL2303 chipset are readily available on Cable Matters’ official website, some equipment might demand proprietary software for communication. Lastly, while this might look somewhat like a VGA cable, don’t be mistaken – it isn’t one! It’s optimized for equipment that’s still reliant on an RS-232 connection.

USBGear USB to RS-232 Serial Adapter

USBGear USB to RS-232 Serial Adapter

Key Takeaways:

  • High-speed baud rate (921.6 Kbps)
  • 10KV surge protection included
  • Powered directly by USB
  • Flexible COM port assignment
  • Might block adjacent USB ports

The USBG-232MINI serial adapter from USBGear proves itself to be a reliable bridge between older serial devices and modern computers equipped with USB ports. Designed in a compact blue chassis measuring 3.4 x 3.1 x 0.7 inches and weighing a mere 0.2 pounds, this device can easily find a spot on any workstation or tucked away in your tech toolkit. At the heart of its functionality, the adapter boasts a high-speed serial port that achieves a baud rate up to 921.6 Kbps.


This adapter has all your RS-232 signal needs covered, from TxD to RxD. But it doesn’t stop at just being comprehensive; it’s got 10KV surge protection to keep your devices safe from voltage spikes.

Nobody wants to wrestle with complicated setups, and thankfully, you don’t have to. Just plug it in, and you’re good to go. Plus, with 512-byte buffers for both sending and receiving, you can count on a smooth data flow. No fuss; just reliable performance.

Powering the unit is hassle-free, as it draws energy directly from the USB port, eliminating the need for external adapters. Another standout attribute is the flexibility to assign any desired COM port number, allowing for better customization based on user preference.


While its build and performance are commendable, it’s worth noting that the product does not include a 3-foot USB cable, as some might expect.

Furthermore, its size can potentially obstruct adjacent USB ports, which might necessitate a short USB extender for some users. USBGear has a reputation for advanced engineering and superior build quality. This adapter is no exception, reflecting the brand’s commitment to delivering reliable products tailored for both legacy and modern tech environments.

USB to Serial (RS-232) Adapter FAQs

What is a USB to serial (RS-232) Adapter, and why would I need one?

Adapters like these serve as indispensable bridges between the old and the new. If you find yourself with a contemporary computer devoid of serial, or RS-232 ports, these adapters save the day.

Are drivers required for USB to serial adapters, and where can I find them?

Most USB to serial adapters require drivers to function correctly, yes. These drivers allow the operating system to recognize and interact with the adapter. Typically, the manufacturer of the adapter will provide the necessary drivers either bundled with the product, on their official website, or both.

Can I use a USB to serial adapter for data transfer between two computers?

Yes, provided both machines support serial communication. But make sure you’re not using a USB data blocker. However, you’ll likely need a null modem cable or adapter, which allows for direct serial communication between two computers.

Final Thoughts

On the hunt for an exceptional USB to Serial adapter? Our top four selections aim to remove the guesswork from your decision.

The USB-A and USB-C to RS-232 adapters from DriverGenius boast a 9-LED activity monitoring system that makes connection diagnostics a cinch.

Switching gears to Gearmo’s offering, this adapter brings a slice of elegance with its sleek design, complete with an LED monitor for real-time connection updates.

In the realm of portability and straightforwardness, Cable Matters offers a lightweight USB to Serial Adapter Cable that features a bus-powered design for plug-and-play operation.

Rounding out our list is the USBGear USB to RS-232 Serial Adapter, a true powerhouse in data transfer speeds, complemented by its 10KV surge protection.

Our picks are the result of a comprehensive evaluation focusing on features, performance, and compatibility. So whether you’re an IT administrator, an engineer, or someone trying to rekindle the utility of older hardware, there’s an adapter in this list custom-fitted to your scenario.

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