Best Serial Cables Under $100 (2026)

We scored cables under $100 by compatibility, build quality, user ratings, feature set (LEDs, changeable connectors, shielding), and overall value

This roundup covers serial cables and adapters under $100, focusing on value-oriented choices for RS232, RS485, DB25/DB9, and PCIe riser applications. Selections prioritize compatibility, build quality, user-rated reliability, and useful features like LED indicators or changeable connectors

Top Picks

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    LINKUP PCIe 5.0 riser cable for vertical GPU mount

    LINKUP PCIe 5.0 riser cable for vertical GPU mount

    LINKUP • ★ 3.7/5 • Mid-Range

    PCIe 5.0 riser cable designed for vertical GPU mounting and standard layouts. Delivers full 128GB/s on PCIe 5.0 x16 with tuned impedance and shielding. Customers note easy alignment and solid build

    • Gen5 x16 performance with full 128GB/s
    • Backward-compatible with PCIe 4.0
    • Ready for next-gen cards and precise GPU placement
    Check current price on Amazon →
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    USB to RS485 Serial Cable with TX/RX LEDs (1.5m) EZSync

    USB to RS485 Serial Cable with TX/RX LEDs (1.5m) EZSync

    EZSync • ★ 3.6/5 • Budget

    USB to RS485 serial interface cable with TX/RX LEDs and over-molded electronics. Compatible with Windows and Mac; suitable for RS485 devices. Customers note easy installation and reliable connectivity in tight spaces

    • TX/RX LEDs for traffic indication
    • Plug-and-play USB to RS485
    • Single-chip USB to asynchronous serial transfer
    Check current price on Amazon →
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    DB9 male to female RS232 extension cable, 12 ft

    DB9 male to female RS232 extension cable, 12 ft

    Custom Cable Connection • ★ 3.4/5 • Mid-Range

    DB9 male to female RS232 extension cable with 24 AWG copper conductors and grey PVC jacket. Provides flexible placement for peripherals and supports straight-through wiring. Customer insight: mentions practical extension for multiple monitor setups

    • metal housings with thumbscrews
    • straight-through wiring
    • DB9 to DB9 extension for RS-232
    Check current price on Amazon →

Buying Guide

Match interface and pinout

Confirm whether you need RS232, RS485, DB25, DB9, or PCIe signals and check straight-through vs. null-modem pinouts to avoid connectivity issues

Consider connector types

Choose between fixed DB9/DB25 cables, USB-to-serial adapters, or PCIe risers depending on device ports and whether you need a cable or an adapter

Check platform and driver support

For USB-to-serial adapters and RS485 converters, verify Windows, macOS, or Linux compatibility and whether drivers are required

Look for useful hardware features

LED TX/RX indicators, changeable DB9 screws or screw-lock connectors, and shielding can simplify troubleshooting and improve signal integrity

Assess length and signal integrity

Long runs (like 100 ft DB25) need quality shielding and proper termination to maintain RS232/RS485 signal reliability