Best Serial Port Cards of 2026

Mike Davis Avatar
Mike Davis
Last Updated: Jan 10, 2026

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Serial port cards are a type of expansion card that can be added to a computer to provide additional serial ports for connecting devices such as modems, printers, and scanners. They are especially useful for older computers that may not have built-in serial ports or for users who require more ports than their computer's built-in ports can provide. Serial port cards typically come in PCI or PCIe formats and can support a range of serial communication standards, including RS-232, RS-422, and RS-485. They are easy to install and can greatly improve the functionality and versatility of a computer.

At a Glance: Our Top Picks

StarTech USB to Serial Adapter Cover #TOP 1
StarTech USB to Serial Adapter
ftb score rating icon 9.9
StarTech PCIe RS232 Serial Adapter PEX1S953LP Cover #TOP 2
StarTech PCIe RS232 Serial Adapter PEX1S953LP
ftb score rating icon 9.8
StarTech PCIe RS232 Serial Adapter Card Cover #TOP 3
StarTech PCIe RS232 Serial Adapter Card
ftb score rating icon 9.6

Top 10 Serial Port Cards

#TOP 1

StarTech USB to Serial Adapter

ICUSB2321F
Black
StarTech USB to Serial Adapter Cover
StarTech 6ft (1.8m) 1-Port FTDI USB to Serial RS232 Adapter Cable with COM Retention, USB to RS232 Adapter - TAA

StarTech USB Serial Adapter is a versatile solution for digital signage, point of sale systems, and barcode scanners. It features an FTDI chipset that makes it highly customizable and compatible with any setup. This compact design is USB powered, eliminating the need for bulky power adapters or an outlet. The simple installation and operation with COM port retention provides a robust serial connectivity for legacy devices. With StarTech USB Serial Adapter, you can easily connect your legacy devices to modern computers or laptops without sacrificing performance or productivity.

What We Like
Versatile
Customizable
Compact
#TOP 2

StarTech PCIe RS232 Serial Adapter PEX1S953LP

PEX1S953LP
Low Profile
StarTech PCIe RS232 Serial Adapter PEX1S953LP Cover
StarTech.com 1-port PCI Express RS232 Serial Adapter Card - PCIe RS232 Serial Host Controller Card - PCIe to Serial DB9 - 16950 UART - Low Profile Expansion Card - Windows & Linux , TAA (PEX1S953LP)

The StarTech PCIe Serial Card is a reliable solution for adding a single RS232 serial port to your desktop or server. It supports high-speed data transfer up to 921.6Kbps, making it ideal for smooth communication with various devices. You can choose from 12v, 5v, or no power output on pin 9, giving you flexibility depending on your hardware needs. The card comes with both low profile and full profile brackets, so you can easily install it in different PC cases. Plus, it works with both Windows and Linux, providing broad compatibility for your system.

What We Like
High-speed RS232 communication
Configurable power output
Includes low and full profile brackets
Compatible with Windows and Linux
#TOP 3

StarTech PCIe RS232 Serial Adapter Card

PEX2S953
Full Profile
StarTech PCIe RS232 Serial Adapter Card Cover
StarTech.com 2-port PCI Express RS232 Serial Adapter Card - PCIe RS232 Serial Host Controller Card - PCIe to Dual Serial DB9 Card - 16950 UART - Expansion Card - Windows & Linux, TAA (PEX2S953)

StarTech Serial Adapter Card is a 2-port PCI Express RS232 controller card that allows you to add two DB9 serial ports to your desktop or server. It is based on ASIX AX99100 and has a 16950 UART, which provides bi-directional RS232 speeds of up to 921.6Kbps per port with an available 256 byte FIFO buffer and 9th data bit. This upgraded version of the popular PEX2S952 card provides optional configurable power with a choice of 12V, 5V, or none through pin 9 with up to 2A total, and each of the two ports is individually configurable. The card comes with a standard profile bracket pre-installed and two low profile brackets included for versatile installation. It is compatible with both Windows and Linux operating systems. The StarTech Serial Adapter Card is an ideal solution for point of sale terminals, PLCs, control/automation in factories, scientific sensors, medical equipment, scanners, and oscilloscopes.

What We Like
2-port serial card
Optional configurable power
Standard & low profile brackets included
#TOP 4

StarTech.com PEX4S953LP 4-Port PCIe RS232 Serial Card

PEX4S953LP
Green
Low Profile
StarTech.com PEX4S953LP 4-Port PCIe RS232 Serial Card Cover
StarTech.com 4-port PCI Express RS232 Serial Adapter Card - PCIe RS232 Serial Host Controller Card - PCIe to Serial DB9 - 16950 UART - Low Profile Expansion Card - Windows & Linux , TAA (PEX4S953LP)

The StarTech 4-Port Serial Card offers four RS232 ports that support fast data transfer speeds up to 921.6Kbps each, making it ideal for connecting multiple serial devices efficiently. It features a 256-byte FIFO buffer, which helps reduce data loss during busy transmissions. You can customize the power supplied to each port individually, choosing between 12V, 5V, or no power, which adds flexibility when powering different connected devices. The card comes with both low profile and standard brackets, allowing easy installation in a variety of desktop and server setups. Compatible with Windows and Linux, this card is a practical choice for diverse serial communication needs.

What We Like
High-speed RS232 communication
Customizable port power options
Includes low and standard brackets
Supports Windows and Linux
#TOP 5

StarTech.com 2-Port PCI Express Serial Card

PEX2S1050
2 Port (SysBase)
StarTech.com 2-Port PCI Express Serial Card Cover
StarTech.com 2-Port PCI Express Serial Card with 16C1050 UART - RS232 Low Profile Serial Card - PCI Serial Card, TAA (PEX2S1050)

The StarTech.com 2-Port PCI Express Serial Card is designed to meet industry standards and is compatible with a wide range of applications. It is a dual port DB9 to PCIe adapter that delivers high-performance serial communication, with support for data transfer rates of up to 460Kbps. The installation is simple as the PCI dual serial adapter features IRQ sharing and supports plug-and-play connection. It has a standard-profile bracket installed, and an optional low-profile bracket.

What We Like
Supports high-performance serial communication
Compatible with a wide range of applications
Simple installation with plug-and-play connection
#TOP 6

LinksTek 2-Port PCI Express RS-232 DB9 Serial Port Card

PCIE-SE2
Matte Black
LinksTek 2-Port PCI Express RS-232 DB9 Serial Port Card Cover
LinksTek 2-Port PCI Express RS-232 DB9 Serial Port Card for Windows XP, Vista,7, 8.x, 10, 11 32/64bit and Linux PCs, PCIE RS232 Card, PCIE Serial DB9 Port Card (PCIE-SE2)

LinksTek 2-Port PCI Express RS-232 DB9 Serial Port Card allows users to add two RS232 BD9 serial Ports on desktop PCs or industrial devices through a PCI Express slot. It seamlessly connects to serial port devices, such as POS systems, industrial testing and control devices, security systems, logistic management equipment, scanners and printers. It requires driver installation on Windows and Linux systems. This card features the ASIX AX99100 solution, which supports on-chip 256-byte depth FIFO in transmit and can work on INTEL, AMD, ARM hardware platforms. The expansion card has a full-size bracket for standard size PCs and two low profile brackets for slim PCs. It can work on PCIe X1, X4, X8, and X16 slots.

What We Like
Can add two RS232 BD9 serial Ports on desktop PCs or industrial devices
Seamlessly connects to various serial port devices
Works on Windows and Linux systems
#TOP 7

Moxa MGate MB3180 Serial to Modbus Gateway

MGATE MB3180
Moxa MGate MB3180 Serial to Modbus Gateway Cover
Moxa MGate MB3180: 1 Port RS-232/422/485 Modbus TCP to Serial Communication Gateway

The Moxa MB3180 Gateway makes connecting your Modbus TCP and serial devices easy and flexible. It automatically finds and routes devices, saving you time on setup. You can configure it simply with straightforward hardware installation. The gateway allows you to direct traffic based on TCP ports or IP addresses, giving you more control over your network layout. Plus, it converts signals between Modbus TCP and Modbus RTU/ASCII, so your devices can communicate smoothly regardless of protocol differences. This makes the Moxa MB3180 Gateway a reliable tool for managing your industrial communication needs efficiently.

What We Like
Auto-Device Routing
Easy hardware setup
Flexible TCP/IP routing
Modbus protocol conversion
#TOP 8

Waveshare Rail-Mount Serial Server

RS232/485/422 TO POE ETH Converter(B)
Waveshare Rail-Mount Serial Server Cover
Waveshare RS232/485/422 to RJ45 Ethernet Module, TCP/IP to Serial, with POE Function, Bi-Directional Transparent Transmission, Suitable for Data Acquisition, Intelligent Instrument Monitoring, etc

Waveshare Serial Server is a versatile, industrial-grade data acquisitor and IoT gateway designed for a range of applications. With RS232/485/422 and Ethernet ports, this module combines multiple functions including serial server, Modbus gateway, MQTT gateway, and RS485 to JSON. The device also features PoE function, a compact design with rail-mount support, and screw terminals for easy installation. This module is ideal for data acquisition, IoT gateway, safety and security IoT, and intelligent instrument monitoring. The Waveshare Serial Server is a cost-effective solution that offers convenience and flexibility for industrial environments.

What We Like
Multi-functional
PoE support
Compact design
#TOP 9

StarTech.com PCIe 1-Port Serial Card

11050-PC-SERIAL-CARD
Yellow
1 Port
StarTech.com PCIe 1-Port Serial Card Cover
StarTech.com 1-Port PCI Express Serial Card, PCIe to RS232 (DB9) Serial Interface Card, PC Serial Card, 16C1050 UART, Standard/Low Profile Brackets, COM Retention, Windows/Linux, TAA

The StarTech PCIe Serial Card lets you easily connect RS232 serial devices like barcode scanners, receipt printers, and medical tools to your computer. It uses a high-performance 16C1050 UART chip, ensuring smooth and reliable data transfer. You can quickly check the connection status thanks to built-in LED lights, which provide visual feedback on activity. This card also supports power delivery through pin 9, supplying 5V or 12V to compatible devices, reducing the need for extra power sources. Plus, it comes with both standard and low-profile brackets, making it easy to install in various PC cases.

What We Like
High-performance UART chip
Built-in LED status indicators
Power supply over pin 9
Includes low-profile bracket
Wide device compatibility
#TOP 10

ANMBEST DB25 Solderless Serial Connector 5PCS

ANMBEST DB25 Solderless Serial Connector 5PCS Cover
ANMBEST 5PCS DB25 Solderless Connector, RS232 D-SUB Serial to 25-pin Port 16mm Thinner Terminal Male Adapter Breakout Board with Case Long Bolts Nuts

The ANMBEST DB25 Serial Adapter offers a durable design with pure copper plated joints and precise soldering, ensuring strong connections and long-lasting use. Its solderless feature lets you skip complicated tools and soldering irons, making wiring quick and simple. The adapter also includes a screw lock mechanism that secures the shell tightly, preventing loose connections or gaps. Plus, the clearly labeled terminal block helps you connect wires correctly, reducing mistakes and saving you time. This adapter is a convenient choice if you want a reliable and easy-to-use solution for serial device connections.

What We Like
Durable copper joints
Solderless wiring
Screw lock shell
Clear terminal labels
Buying Guide Image

Why We Recommend Serial Port Cards

Introduction

When it comes to choosing a serial port card, there are a few key factors to consider. In this article, we will discuss what to look for in a serial port card, as well as some common types and features to consider.

Types of Serial Port Cards

There are several different types of serial port cards available, each with its own unique set of features and capabilities. Some of the most common types of serial port cards include:

  • PCI serial port cards: These cards are designed to be installed in a PCI slot on a computer motherboard, and provide additional serial port connectivity.

  • USB serial port cards: These cards use a USB connection to provide additional serial port connectivity.

  • PCIe serial port cards: These cards are designed to be installed in a PCIe slot on a computer motherboard, and provide high-speed serial port connectivity.

Features to Consider

When choosing a serial port card, there are a few key features to consider. Some of the most important features to look for include:

  • Number of serial ports: The number of serial ports on a serial port card can vary, so it's important to choose a card that has enough ports to meet your needs.

  • Data transfer rates: The data transfer rate of a serial port card determines how quickly data can be transferred over the serial connection. Higher data transfer rates are generally better, but they may also be more expensive.

  • Compatibility: It's important to make sure that the serial port card you choose is compatible with your computer and operating system. Check the manufacturer's website for compatibility information before making a purchase.

  • Price: The price of a serial port card can vary depending on the type and features it offers. Consider your budget and the features you need when choosing a serial port card.

Conclusion

Choosing the right serial port card can be a daunting task, but by considering the types, features, compatibility, and price, you can find a card that meets your needs and fits your budget. With the right serial port card, you can expand the connectivity of your computer and take advantage of all the possibilities that serial communication has to offer.

Frequently Asked Questions (FAQs)

1. Is PCIe a serial port?

No, PCIe is not a serial port itself. It is a high-speed interface that can be used to connect a PCIe serial card, which enables high-performance serial communication with support for data transfer rates up to 921.6 Kbps.

2. What still uses serial ports?

Serial ports are still commonly used in applications that require simple, low-speed interfaces. Industries such as industrial automation, scientific instruments, point of sale systems, and certain industrial and consumer products often rely on serial ports for connectivity.

3. What is the use of serial card?

A serial card is typically used to add a serial RS232 port to a computer. This port can be used to connect various RS232 devices. Additionally, serial port cards can also be used to create multiple RS485 or RS422 ports, depending on the specific card.

4. Do all PCs have a serial port?

No, most modern PCs do not come with a built-in serial port. Serial ports are still in use, but they are not commonly found on mainstream computer motherboards. Users requiring serial port connectivity may need to use a serial port card or USB-to-serial adapter.

5. Is PCIe still used?

Yes, PCIe is still widely used as a high-speed interface for connecting various subsystems on a motherboard. However, when it comes to expansion slots, most laptops and mini-PCs do not offer PCIe slots other than for M.2 SSD interfaces.

6. Which is better PCI or PCIe?

PCIe is an improved and faster version of PCI. While both are buses with some similar functions, PCIe offers greater speed and can support devices like graphics cards that PCI cannot handle in modern systems.

7. Is RS-232 obsolete?

While RS-232 ports have been replaced by other standards like USB in mainstream personal computers, they are still in use in certain applications. The RS-232 serial cable has not become entirely obsolete and continues to be used in specific contexts.

8. Is serial port obsolete?

Serial ports are still in use, but they are not commonly found on modern computer motherboards. Mainstream computer users rarely have a need for serial ports, so it may be challenging to find a modern motherboard with a 9-pin serial port as part of the I/O ports.

Editor's Notes

During our serial port card research, we found 24 serial port card products and shortlisted 10 quality products. We collected and analyzed 5,965 customer reviews through our big data system to write the serial port cards list. We found that most customers choose serial port cards with an average price of $85.09.

The serial port cards are available for purchase. We have researched hundreds of brands and picked the top brands of serial port cards, including StarTech, LinksTek, Moxa, waveshare, ANMBEST. The seller of top 1 product has received honest feedback from 384 consumers with an average rating of 4.7.

Written by
Mike Davis Avatar

Mike Davis is a professionally trained electrician with six years of working experience in the electronics industry. He has written an array of web and mobile-based articles for e-magazines and blogs. He loves trying out some novel and popular gadgets and his expertise is in the areas of electronics and computers which is built over many years of working and personal experiences.