Best Serial Adapters Under $100 (2026)
We ranked products by value score using chipset reliability, interface versatility, build quality, included accessories, and overall utility for under $100
The Verdict
- Best Overall: USB to RS232 adapter with FTDI chipset — Best for single-port PC connections: a USB-to-RS232 adapter with an FTDI chipset for stable, wide OS support
- Best Value: DB9 Male Breakout Connector with Case — Best for quick wiring: a DB9 male breakout with case that simplifies serial pin access without soldering
This roundup covers reliable serial adapters and breakout connectors under $100, focused on RS232/TTL/RS485 interfaces, breakout options, and multi-port USB converters. Picks were chosen for practical value using chipset reliability, interface versatility, build style (breakout vs. cable vs. gateway), and overall user utility
Top Picks
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1
Best Overall USB to RS232 adapter with FTDI chipset
Best for single-port PC connections: a USB-to-RS232 adapter with an FTDI chipset for stable, wide OS support
USB to serial RS232 adapter converting USB to a null modem DB9 port. Compatible with Windows, Mac, and Linux. Customers praise plug-and-play setup and reliable FTDI FT232R chip
- FTDI-based reliability
- USB to RS232 null modem capability
- cross-platform compatibility
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2
Best Value DB9 Male Breakout Connector with Case
Best for quick wiring: a DB9 male breakout with case that simplifies serial pin access without soldering
DB9 solderless breakout board for RS232 serial connections. Provides easy wiring and durable joints for reliable signal transfer. Customers note solid quality and ease of use, though some find it bulky
- solderless terminal adapter
- case with long bolts
- pure copper plated joints
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3
DB9 breakout connector set (5 male + 5 female) with case
Best for small labs: a 5× male and 5× female DB9 breakout set that provides multiple solderless connectors in one kit
DB9 breakout boards for RS232 serial connections with solderless terminals and durable casing. Easy to wire and assemble; customers note good quality and functionality
- solderless DB9 terminals
- case-protected breakout
- mixed-quality but functional reviews
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4
Gearmo 4 Port USB to RS232 Adapter with FTDI
Best for multi-device setups: a 4-port USB-to-RS232 adapter using FTDI for dependable multi-serial connections
USB to RS-232 adapter with four ports and FTDI chipset for cross-platform use. Plug-and-play with COM port retention for stable serial connections. Customers note reliable Linux compatibility and solid build quality
- multiplatform compatibility
- four COM ports
- no external power required
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5
DB15 Solderless Connector 15-pin Breakout Board with Case
Best for DB15 projects: a solderless 15-pin breakout board in a case for easy prototyping and signal access
Solderless DB15 breakout board for RS232 D-SUB ports, with a durable copper joint and protective PP casing. Customers note ease of use and reliable functionality
- durable solder joints
- easy-to-use breakout
- protective outer case
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6
DB9 Female Breakout Connector 10-pack
for quantity: a 10-pack of DB9 female solderless breakouts useful for bulk prototyping or inventory
DB9 female breakout board for solderless RS232 connections with case. Helps wire and build serial cables; users report good quality and ease of use
- solderless RS232 breakout
- durable outer casing
- easy wiring
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7
4 Port USB to RS232 DB9 Serial Adapter Cable (5ft) ELECABLE
Best for longer runs: a 4-port 5ft USB-to-RS232 cable set that combines multiple serial ports with convenient cable length
USB to RS-232 adapter supporting 4 ports, compatible with MAC, Windows, Android, Linux. Provides remote wake up and power management; suitable for GPS, modems, printers, scanners, cameras. Customer note: reliable performance and good cable quality
- 4-port RS-232 support
- USB to RS-232 conversion
- remote wake up and power management
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8
USB/RS232/TLL to RS232/485/TLL Multibus Converter
Best for mixed-level projects: a multibus converter that bridges USB, RS232, TTL, and RS485 with isolation-minded features
Industrial isolated converter supporting USB, RS232, TTL to RS232, 485, TTL with onboard power isolation and protection circuits. Built on FT232RL for reliable USB communication
- multibus isolated converter
- USB/RS232/TTL to RS232/485/TLL
- onboard isolation and protection
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9
DB9 Solderless Breakout Connector 3Male+3Female 9-pin
Best compact breakout pack: a 3-male plus 3-female DB9 solderless set for quick custom serial wiring
DB9 solderless breakout with labeled ports for quick wiring. Copper joints and 24K gold-plated connector enhance connectivity and durability. 16mm thin case for flexible wiring
- clear port labeling on both sides
- durable copper joints with gold plating
- lead-free RoHS compliant
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10
DR302 DIN Rail Modbus Gateway: RTU to TCP RS485 to Ethernet
Best for industrial networking: a DIN-rail Modbus gateway that converts RTU/RS485 to TCP Ethernet for automation systems
Modbus gateway converting RTU to TCP/UDP with RS485 to Ethernet. Compact, lightweight, simple configuration. Customer insight hints at ease of use
- Modbus RTU to Modbus TCP conversion
- DIN rail mounted gateway
- multi-protocol server/client support