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Plugable USB to Serial RS-232 Adapter (5ft) with COM Retention - Compatible with Windows, Mac, Linux (DB9 DTE Male Connector, Prolific PL2303GT Chipset, Up to 1Mbps) - PL2303-DB9
Plugable

Plugable USB to Serial RS-232 Adapter (5ft) with COM Retention (PL2303-DB9)

Bottom line: The Plugable USB to Serial RS-232 Adapter with COM Retention ($19.96 on Amazon as of 2026-10-06): Genuine Prolific PL2303GT chipset avoids counterfeit-driver blocks; main trade-off: 5ft fixed cable length may not reach rack-mounted or floor equipment.

$19.96

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Buy on Amazon — $19.96 Compare to similar cables & connectors

By , Founder & Editor-in-Chief · Listing data updated

Mike Perry — Hardware researcher since 2014. For retro PC hardware and period-correct parts, synthesises manufacturer documentation, community compatibility lists and marketplace listings rather than first-hand lab testing. Core beat: GPU performance across gaming, rendering, and local-LLM inference.

*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.

Pros & Cons

Pros

  • ✓ Genuine Prolific PL2303GT chipset avoids counterfeit-driver blocks
  • ✓ COM retention keeps the same port number and settings after reboots
  • ✓ Programmable baud rate spans 75bps to 1Mbps
  • ✓ USB bus-powered, no external power adapter required
  • ✓ 2-year limited parts and labor warranty with North American support

Cons

  • ✗ 5ft fixed cable length may not reach rack-mounted or floor equipment
  • ✗ DB9 DTE male only, needs a NULL modem cable for DTE-to-DTE links
  • ✗ Single port, so multiple serial devices mean multiple adapters
  • ✗ Prolific driver install may still be needed on older Windows builds

Manufacturer description

The Plugable PL2303-DB9 USB to Serial RS-232 Adapter puts a real DB9 COM port back on a machine that shipped without one. The 5ft cable terminates in a DB9 DTE male connector and draws all its power over USB, so there is no wall wart to find a spot for. Inside is a genuine Prolific PL2303GT chipset, which is why this adapter enumerates cleanly on Windows 11, 10, 8.x, 7 and Vista, plus Mac and Linux, instead of tripping the counterfeit-chip driver blocks that plague no-name adapters. Baud rate is programmable from 75bps all the way to 1Mbps, covering everything from a vintage modem or serial…

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SpecPicks Verdict

SpecPicks scored Plugable USB to Serial RS-232 Adapter with COM Retention using a rating × review-volume × price-fit model applied to published specs and reviews across the cables & connectors category. Plugable's cables & connectors lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.

Common buyer scenarios for cables & connectors of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.

Frequently Asked Questions

Will this work on Windows 11 and macOS?

Yes. The genuine Prolific PL2303GT chipset supports Windows 11, 10, 8.x, 7 and Vista, plus Mac, Linux and other platforms.

Does the COM port number change every time I reboot?

No. This adapter features COM retention, which maintains the assigned port number and its settings across reboots, so scripts and terminal profiles keep working.

What baud rates does it support?

The adapter supports a programmable baud rate from 75bps up to 1Mbps, covering legacy modems, serial consoles and higher-speed instrumentation.

Do I need a separate power supply?

No. It is powered entirely over USB, so no external power brick is needed.

Do I need an extra cable to connect my device?

Usually yes. The adapter ends in a DB9 DTE male connector, and Plugable recommends pairing it with a serial cable or a NULL modem cable depending on your device.

Key Features

  • USB To RS232 Serial Adapter (5ft) - Connect legacy DB-9 serial communications devices to a modern computer over USB. Powered by USB; no external power needed
  • Legacy Support - Add a 9-pin DB9 RS-232 serial port to any modern computer, replaces built-in or PCIe serial adapters, recommended for use with a serial cable or NULL modem cable
  • Compatibility Guarantee - Genuine Prolific PL2303GT Chipset for widest possible compatibility with Windows (11, 10, 8.x, 7, and Vista), Mac, Linux, and other platforms
  • Flexible - The USB RS-232 adapter supports a programmable baud rate from 75bps to 1Mbps. This RS232 USB Adapter allows for a plug-and-play creation of a COM port. Features COM retention to maintain port number and settings across reboots
  • Warranty and Support - Questions only an expert can answer? When you contact our support team, you’re connecting with the engineers who design our devices. Every Plugable product is backed by our North American support team–even before purchase, and a 2-year limited parts and labor warranty after purchase

Full Specifications

BrandPlugable
ColorGrey
FinishGlossy
Unit Count1 Count
ConnectivityUSB
Model NumberPL2303-DB9
CompatibilityMac, Linux
Warranty TypeLimited
Built-In MediaSerial adapter
Connector TypeUSB Type A
Item Type NamePL-2303HX Serial Adapter
Item Dimensions26.5 x 1.5 x 0.6 inches
Mfr Part NumberPL2303-DB9
Number of Items1
Number of Ports1
Power Plug TypeNo Plug
Compatible DevicesWindows (11, 10, 8.x, 7, Vista), macOS, Linux
Warranty Description2 Year Limited Parts and Labor
Item dimensions L x W x H26.5 x 1.5 x 0.6 inches
Specific Uses For ProductPC
Full listing titlePlugable USB to Serial RS-232 Adapter (5ft) with COM Retention - Compatible with Windows, Mac, Linux (DB9 DTE Male Connector, Prolific PL2303GT Chipset, Up to 1Mbps) - PL2303-DB9

Ready to buy?

Plugable USB to Serial RS-232 Adapter (5ft) with COM Retention - Compatible with Windows, Mac, Linux (DB9 DTE Male Connector, Prolific PL2303GT Chipset, Up to 1Mbps) - PL2303-DB9 is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.

Buy on Amazon — $19.96

*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.

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Plugable USB to Serial RS-232 Adapter (5ft) with COM Retention - Compatible with Windows, Mac, Linux (DB9 DTE Male Connector, Prolific PL2303GT Chipset, Up to 1Mbps) - PL2303-DB9
$19.96
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